HTTP Headers

9 Method Definitions

The set of common methods for HTTP/1.1 is defined below. Although this set can be expanded, additional methods cannot be assumed to share the same semantics for separately extended clients and servers.

The Host request-header field (section 14.23) MUST accompany all HTTP/1.1 requests.

9.1 Safe and Idempotent Methods

9.1.1 Safe Methods

Implementors should be aware that the software represents the user in their interactions over the Internet, and should be careful to allow the user to be aware of any actions they might take which may have an unexpected significance to themselves or others.

In particular, the convention has been established that the GET and HEAD methods SHOULD NOT have the significance of taking an action other than retrieval. These methods ought to be considered "safe". This allows user agents to represent other methods, such as POST, PUT and DELETE, in a special way, so that the user is made aware of the fact that a possibly unsafe action is being requested.

Naturally, it is not possible to ensure that the server does not generate side-effects as a result of performing a GET request; in fact, some dynamic resources consider that a feature. The important distinction here is that the user did not request the side-effects, so therefore cannot be held accountable for them.

9.1.2 Idempotent Methods

Methods can also have the property of "idempotence" in that (aside from error or expiration issues) the side-effects of N > 0 identical requests is the same as for a single request. The methods GET, HEAD, PUT and DELETE share this property. Also, the methods OPTIONS and TRACE SHOULD NOT have side effects, and so are inherently idempotent.

However, it is possible that a sequence of several requests is non- idempotent, even if all of the methods executed in that sequence are idempotent. (A sequence is idempotent if a single execution of the entire sequence always yields a result that is not changed by a reexecution of all, or part, of that sequence.) For example, a sequence is non-idempotent if its result depends on a value that is later modified in the same sequence.

A sequence that never has side effects is idempotent, by definition (provided that no concurrent operations are being executed on the same set of resources).

9.2 OPTIONS

The OPTIONS method represents a request for information about the communication options available on the request/response chain identified by the Request-URI. This method allows the client to determine the options and/or requirements associated with a resource, or the capabilities of a server, without implying a resource action or initiating a resource retrieval.

Responses to this method are not cacheable.

If the OPTIONS request includes an entity-body (as indicated by the presence of Content-Length or Transfer-Encoding), then the media type MUST be indicated by a Content-Type field. Although this specification does not define any use for such a body, future extensions to HTTP might use the OPTIONS body to make more detailed queries on the server. A server that does not support such an extension MAY discard the request body.

If the Request-URI is an asterisk ("*"), the OPTIONS request is intended to apply to the server in general rather than to a specific resource. Since a server's communication options typically depend on the resource, the "*" request is only useful as a "ping" or "no-op" type of method; it does nothing beyond allowing the client to test the capabilities of the server. For example, this can be used to test a proxy for HTTP/1.1 compliance (or lack thereof).

If the Request-URI is not an asterisk, the OPTIONS request applies only to the options that are available when communicating with that resource.

A 200 response SHOULD include any header fields that indicate optional features implemented by the server and applicable to that resource (e.g., Allow), possibly including extensions not defined by this specification. The response body, if any, SHOULD also include information about the communication options. The format for such a

body is not defined by this specification, but might be defined by future extensions to HTTP. Content negotiation MAY be used to select the appropriate response format. If no response body is included, the response MUST include a Content-Length field with a field-value of "0".

The Max-Forwards request-header field MAY be used to target a specific proxy in the request chain. When a proxy receives an OPTIONS request on an absoluteURI for which request forwarding is permitted, the proxy MUST check for a Max-Forwards field. If the Max-Forwards field-value is zero ("0"), the proxy MUST NOT forward the message; instead, the proxy SHOULD respond with its own communication options. If the Max-Forwards field-value is an integer greater than zero, the proxy MUST decrement the field-value when it forwards the request. If no Max-Forwards field is present in the request, then the forwarded request MUST NOT include a Max-Forwards field.

9.3 GET

The GET method means retrieve whatever information (in the form of an entity) is identified by the Request-URI. If the Request-URI refers to a data-producing process, it is the produced data which shall be returned as the entity in the response and not the source text of the process, unless that text happens to be the output of the process.

The semantics of the GET method change to a "conditional GET" if the request message includes an If-Modified-Since, If-Unmodified-Since, If-Match, If-None-Match, or If-Range header field. A conditional GET method requests that the entity be transferred only under the circumstances described by the conditional header field(s). The conditional GET method is intended to reduce unnecessary network usage by allowing cached entities to be refreshed without requiring multiple requests or transferring data already held by the client.

The semantics of the GET method change to a "partial GET" if the request message includes a Range header field. A partial GET requests that only part of the entity be transferred, as described in section 14.35. The partial GET method is intended to reduce unnecessary network usage by allowing partially-retrieved entities to be completed without transferring data already held by the client.

The response to a GET request is cacheable if and only if it meets the requirements for HTTP caching described in section 13.

See section 15.1.3 for security considerations when used for forms.

9.4 HEAD

The HEAD method is identical to GET except that the server MUST NOT return a message-body in the response. The metainformation contained in the HTTP headers in response to a HEAD request SHOULD be identical to the information sent in response to a GET request. This method can be used for obtaining metainformation about the entity implied by the request without transferring the entity-body itself. This method is often used for testing hypertext links for validity, accessibility, and recent modification.

The response to a HEAD request MAY be cacheable in the sense that the information contained in the response MAY be used to update a previously cached entity from that resource. If the new field values indicate that the cached entity differs from the current entity (as would be indicated by a change in Content-Length, Content-MD5, ETag or Last-Modified), then the cache MUST treat the cache entry as stale.

9.5 POST

The POST method is used to request that the origin server accept the entity enclosed in the request as a new subordinate of the resource identified by the Request-URI in the Request-Line. POST is designed to allow a uniform method to cover the following functions:

      - Annotation of existing resources; 

      - Posting a message to a bulletin board, newsgroup, mailing list, or similar group of articles; 

      - Providing a block of data, such as the result of submitting a form, to a data-handling process; 

      - Extending a database through an append operation. 

The actual function performed by the POST method is determined by the server and is usually dependent on the Request-URI. The posted entity is subordinate to that URI in the same way that a file is subordinate to a directory containing it, a news article is subordinate to a newsgroup to which it is posted, or a record is subordinate to a database.

The action performed by the POST method might not result in a resource that can be identified by a URI. In this case, either 200 (OK) or 204 (No Content) is the appropriate response status, depending on whether or not the response includes an entity that describes the result.

If a resource has been created on the origin server, the response SHOULD be 201 (Created) and contain an entity which describes the status of the request and refers to the new resource, and a Location header (see section 14.30).

Responses to this method are not cacheable, unless the response includes appropriate Cache-Control or Expires header fields. However, the 303 (See Other) response can be used to direct the user agent to retrieve a cacheable resource.

POST requests MUST obey the message transmission requirements set out in section 8.2.

See section 15.1.3 for security considerations.

9.6 PUT

The PUT method requests that the enclosed entity be stored under the supplied Request-URI. If the Request-URI refers to an already existing resource, the enclosed entity SHOULD be considered as a modified version of the one residing on the origin server. If the Request-URI does not point to an existing resource, and that URI is capable of being defined as a new resource by the requesting user agent, the origin server can create the resource with that URI. If a new resource is created, the origin server MUST inform the user agent via the 201 (Created) response. If an existing resource is modified, either the 200 (OK) or 204 (No Content) response codes SHOULD be sent to indicate successful completion of the request. If the resource could not be created or modified with the Request-URI, an appropriate error response SHOULD be given that reflects the nature of the problem. The recipient of the entity MUST NOT ignore any Content-* (e.g. Content-Range) headers that it does not understand or implement and MUST return a 501 (Not Implemented) response in such cases.

If the request passes through a cache and the Request-URI identifies one or more currently cached entities, those entries SHOULD be treated as stale. Responses to this method are not cacheable.

The fundamental difference between the POST and PUT requests is reflected in the different meaning of the Request-URI. The URI in a POST request identifies the resource that will handle the enclosed entity. That resource might be a data-accepting process, a gateway to some other protocol, or a separate entity that accepts annotations. In contrast, the URI in a PUT request identifies the entity enclosed with the request -- the user agent knows what URI is intended and the server MUST NOT attempt to apply the request to some other resource. If the server desires that the request be applied to a different URI,

it MUST send a 301 (Moved Permanently) response; the user agent MAY then make its own decision regarding whether or not to redirect the request.

A single resource MAY be identified by many different URIs. For example, an article might have a URI for identifying "the current version" which is separate from the URI identifying each particular version. In this case, a PUT request on a general URI might result in several other URIs being defined by the origin server.

HTTP/1.1 does not define how a PUT method affects the state of an origin server.

PUT requests MUST obey the message transmission requirements set out in section 8.2.

Unless otherwise specified for a particular entity-header, the entity-headers in the PUT request SHOULD be applied to the resource created or modified by the PUT.

9.7 DELETE

The DELETE method requests that the origin server delete the resource identified by the Request-URI. This method MAY be overridden by human intervention (or other means) on the origin server. The client cannot be guaranteed that the operation has been carried out, even if the status code returned from the origin server indicates that the action has been completed successfully. However, the server SHOULD NOT indicate success unless, at the time the response is given, it intends to delete the resource or move it to an inaccessible location.

A successful response SHOULD be 200 (OK) if the response includes an entity describing the status, 202 (Accepted) if the action has not yet been enacted, or 204 (No Content) if the action has been enacted but the response does not include an entity.

If the request passes through a cache and the Request-URI identifies one or more currently cached entities, those entries SHOULD be treated as stale. Responses to this method are not cacheable.

9.8 TRACE

The TRACE method is used to invoke a remote, application-layer loop- back of the request message. The final recipient of the request SHOULD reflect the message received back to the client as the entity-body of a 200 (OK) response. The final recipient is either the

origin server or the first proxy or gateway to receive a Max-Forwards value of zero (0) in the request (see section 14.31). A TRACE request MUST NOT include an entity.

TRACE allows the client to see what is being received at the other end of the request chain and use that data for testing or diagnostic information. The value of the Via header field (section 14.45) is of particular interest, since it acts as a trace of the request chain. Use of the Max-Forwards header field allows the client to limit the length of the request chain, which is useful for testing a chain of proxies forwarding messages in an infinite loop.

If the request is valid, the response SHOULD contain the entire request message in the entity-body, with a Content-Type of "message/http". Responses to this method MUST NOT be cached.

9.9 CONNECT

This specification reserves the method name CONNECT for use with a proxy that can dynamically switch to being a tunnel (e.g. SSL tunneling [44]).

List of HTTP Response Status Codes

1xx Info / Informational

HTTP_INFO - Request received, continuing process.

Indicates a provisional response, consisting only of the Status-Line and optional headers, and is terminated by an empty line.

• 100 Continue - HTTP_CONTINUE
• 101 Switching Protocols - HTTP_SWITCHING_PROTOCOLS
• 102 Processing - HTTP_PROCESSING

2xx Success / OK

HTTP_SUCCESS - The action was successfully received, understood, and accepted.

Indicates that the client's request was successfully received, understood, and accepted.

• 200 OK - HTTP_OK
• 201 Created - HTTP_CREATED
• 202 Accepted - HTTP_ACCEPTED
• 203 Non-Authoritative Information - HTTP_NON_AUTHORITATIVE
• 204 No Content - HTTP_NO_CONTENT
• 205 Reset Content - HTTP_RESET_CONTENT
• 206 Partial Content - HTTP_PARTIAL_CONTENT
• 207 Multi-Status - HTTP_MULTI_STATUS

3xx Redirect

HTTP_REDIRECT - The client must take additional action to complete the request.

Indicates that further action needs to be taken by the user-agent in order to fulfill the request. The action required may be carried out by the user agent without interaction with the user if and only if the method used in the second request is GET or HEAD. A user agent should not automatically redirect a request more than 5 times, since such redirections usually indicate an infinite loop.

• 300 Multiple Choices - HTTP_MULTIPLE_CHOICES
• 301 Moved Permanently - HTTP_MOVED_PERMANENTLY
• 302 Found - HTTP_MOVED_TEMPORARILY
• 303 See Other - HTTP_SEE_OTHER
• 304 Not Modified - HTTP_NOT_MODIFIED
• 305 Use Proxy - HTTP_USE_PROXY
• 306 unused - UNUSED
• 307 Temporary Redirect - HTTP_TEMPORARY_REDIRECT

4xx Client Error

HTTP_CLIENT_ERROR - The request contains bad syntax or cannot be fulfilled.

Indicates case where client seems to have erred. Except when responding to a HEAD request, the server should include an entity containing an explanation of the error situation, and whether it is a temporary or permanent condition.

• 400 Bad Request - HTTP_BAD_REQUEST
• 401 Authorization Required - HTTP_UNAUTHORIZED
• 402 Payment Required - HTTP_PAYMENT_REQUIRED
• 403 Forbidden - HTTP_FORBIDDEN
• 404 Not Found - HTTP_NOT_FOUND
• 405 Method Not Allowed - HTTP_METHOD_NOT_ALLOWED
• 406 Not Acceptable - HTTP_NOT_ACCEPTABLE
• 407 Proxy Authentication Required - HTTP_PROXY_AUTHENTICATION_REQUIRED
• 408 Request Time-out - HTTP_REQUEST_TIME_OUT
• 409 Conflict - HTTP_CONFLICT
• 410 Gone - HTTP_GONE
• 411 Length Required - HTTP_LENGTH_REQUIRED
• 412 Precondition Failed - HTTP_PRECONDITION_FAILED
• 413 Request Entity Too Large - HTTP_REQUEST_ENTITY_TOO_LARGE
• 414 Request-URI Too Large - HTTP_REQUEST_URI_TOO_LARGE
• 415 Unsupported Media Type - HTTP_UNSUPPORTED_MEDIA_TYPE
• 416 Requested Range Not Satisfiable - HTTP_RANGE_NOT_SATISFIABLE
• 417 Expectation Failed - HTTP_EXPECTATION_FAILED
• 418 unused - UNUSED
• 419 unused - UNUSED
• 420 unused - UNUSED
• 421 unused - UNUSED
• 422 Unprocessable Entity - HTTP_UNPROCESSABLE_ENTITY
• 423 Locked - HTTP_LOCKED
• 424 Failed Dependency - HTTP_FAILED_DEPENDENCY
• 425 No code - HTTP_NO_CODE
• 426 Upgrade Required - HTTP_UPGRADE_REQUIRED

5xx Server Error

HTTP_SERVER_ERROR - The server failed to fulfill an apparently valid request.

Indicate cases in which the server is aware that it has erred or is incapable of performing the request. Except when responding to a HEAD request, the server should include an entity containing an explanation of the error situation, and whether it is a temporary or permanent condition. User agents should display any included entity to the user. These response codes are applicable to any request method.

• 500 Internal Server Error - HTTP_INTERNAL_SERVER_ERROR
• 501 Method Not Implemented - HTTP_NOT_IMPLEMENTED
• 502 Bad Gateway - HTTP_BAD_GATEWAY
• 503 Service Temporarily Unavailable - HTTP_SERVICE_UNAVAILABLE
• 504 Gateway Time-out - HTTP_GATEWAY_TIME_OUT
• 505 HTTP Version Not Supported - HTTP_VERSION_NOT_SUPPORTED
• 506 Variant Also Negotiates - HTTP_VARIANT_ALSO_VARIES
• 507 Insufficient Storage - HTTP_INSUFFICIENT_STORAGE
• 508 unused - UNUSED
• 509 unused - UNUSED
• 510 Not Extended - HTTP_NOT_EXTENDED

Helpful HTTP Links

1. HTTP specification, Section 10
2. TLS Upgrade within HTTP specification, Section 4
3. HTTP Status Code Registry
4. WebDAV specification, Section 11
5. IANA registry
6. Adobe Flash status code definitions (ie 408)
7. Microsoft Internet Information Server Status Codes and Sub-Codes
8. httplint
9. HTTP Headers, brief intro.
10. Common User-Agent Issues

DRP

"The HTTP Distribution and Replication Protocol"

DupSup

"Duplicate Suppression in HTTP"

EARL Schema

"Evaluation and Report Language (EARL) 1.0 Schema"

EDD

"An exploration of dynamic documents"

EdgeArch

"Edge Architecture Specification"

HttpClient

Jakarta Commons HttpClient

HTML4

"HTML 4.01 Specification"

JEPI

"White Paper: Joint Electronic Payment Initiative"

ObjectHeaders

"Object Header lines in HTTP"

OPS-OverHTTP

"Implementation of OPS Over HTTP"

OPTIONS messages

"Specification of HTTP/1.1 OPTIONS messages"

P3P

"The Platform for Privacy Preferences 1.0 (P3P1.0) Specification"

PEP

"PEP - an Extension Mechanism for HTTP"

PICSLabels

"PICS Label Distribution Label Syntax and Communication Protocols, Version 1.1"

Proxy Notification

"Notification for Proxy Caches"

RDF

"Resource Description Framework (RDF): Concepts and Abstract Syntax"

RDF-PRIMER

RDF Primer

RFC2068

"Hypertext Transfer Protocol -- HTTP/1.1"

RFC2109

"HTTP State Management Mechanism"

RFC2183

"Communicating Presentation Information in Internet Messages: The Content-Disposition Header Field"

RFC2227

"Simple Hit-Metering and Usage-Limiting for HTTP"

RFC2295

"Transparent Content Negotiation in HTTP"

RFC2310

"The Safe Response Header Field"

RFC2324

"Hyper Text Coffee Pot Control Protocol (HTCPCP/1.0)"

RFC2397

"The 'data' URL scheme"

RFC2518

"HTTP Extensions for Distributed Authoring -- WEBDAV"

RFC2616

"Hypertext Transfer Protocol -- HTTP/1.1"

RFC2617

"HTTP Authentication: Basic and Digest Access Authentication"

RFC2660

"The Secure HyperText Transfer Protocol"

RFC2774

"An HTTP Extension Framework"

RFC2965

"HTTP State Management Mechanism"

RFC3229

"Delta encoding in HTTP"

RFC3230

"Instance Digests in HTTP"

RFC3253

"Versioning Extensions to WebDAV (Web Distributed Authoring and Versioning)"

RFC3648

"Web Distributed Authoring and Versioning (WebDAV) Ordered Collections Protocol"

RFC3986

"Uniform Resource Identifier (URI): Generic Syntax"

RFC4229

"HTTP Header Field Registrations"

SOAP1.1

"Simple Object Access Protocol (SOAP) 1.1"

UA Attributes

"User-Agent Display Attributes Headers"

WIRE

"WIRE - W3 Identifier Resolution Extensions"

Raw HTTP Header Debugger originally appeared on AskApache.com

Lightning Strikes Twice!

LOL..

3rd Dimension Broken with Bash!

So 3D... it'll hurt you eyes! lol.. Man I am cracking up here. Ha but seriously those really do look 3D for terminal though.. I am actually really impressed. Sweet. Here is the little function I wrote to output that grey marble.

Just a word to the wise, start learning and going over some of these concepts, especially the code used in functions, I will be back in a followup that details actually using this stu.

This function is one of my favorites because it is so fast and useful. Like when designing a 256color prompt.

aa_256 ()
{
    local o x=`tput op` y=`printf %$((${COLUMNS}-6))s`;
    for i in {0..256};
    do
        o=00$i;
        echo -e ${o:${#o}-3:3} `tputm "setaf $i" "setab $i"`${y// /=}$x;
    done
}

Ya this is actually not very helpful or useful, but there you have it.

tputm ()
{
    local a;
    for a in "$@";
    do
        echo -en "${a}\n";
    done | tput -S
}

Some people call this function the grey bringer of death. Not really.

a256 ()
{
    ( x=`tput op` y=`printf %$((${COLUMNS}-6))slocal `;
    for i in {242..232} 232 232;
    do
        echo -en "`tput setaf $i;tput setab $i`${y}${x}`tput op`";
    done )
}

Helpful Ncurses Programs

ALWAYS check out my functions!

This function will print out the terminal, show it's colors, etc.. I have some really nice ones in this article that I use for tmux, screen, and that sort of thing.

c ()
{
    tput clear;
    pm "$TERM: [colors:`tput colors`/`tput pairs`]";
    RC=`tput op` L1=$(L '=' $(( ${COLUMNS} - 25 )));
    for i in `seq ${1:-0} ${2:-16}`;
    do
        o="  $i";
        echo -e " ${o:${#o}-3:3} `tput setaf $i;tput setab $i`${L1}${RC}";
    done
}

Standard Capabilities

X.364 and iBCS2

• \033c - RIS - full reset
• \0337 - SC - save cursor
• \0338 - RC - restore cursor
• \033[r - RSR - not an X.364 mnemonic
• \033[m - SGR0 - not an X.364 mnemonic
• \033[2J - ED2 - clear page

Specified by ISO 2022

• \033(0 - ISO DEC G0 - enable DEC graphics for G0
• \033(A - ISO UK G0 - enable UK chars for G0
• \033(B - ISO US G0 - enable US chars for G0
• \033)0 - ISO DEC G1 - enable DEC graphics for G1
• \033)A - ISO UK G1 - enable UK chars for G1
• \033)B - ISO US G1 - enable US chars for G1

ISO 2022 charset switching:

• ISO/IEC 2022:1994
• "Character code structure and extension techniques"
• ECMA-035
• code structure
  • =00..=1F C0 set of control characters
  • =20..=7F G0 set of 94 or 96 graphic characters
  • =80..=9F C1 set of control characters "C1 controls"
  • =A0..=FF G1 set of 94 or 96 graphic characters
  • ... G2 and G3
• registration authority
  • ISO/IEC 2375:1985 Procedure for registration of escape sequences
  • "ECMA registry"
  • ISO-IR registration number
  • ftp://dkuug.dk/i18n/iso2375reg.txt
  • Internaltional register of coded character sets to be used with escape sequences
  • ISO/IEC JTC1/SC2/WG3
• ISO-2022 terminals from Siemens
• recode iso-2022..utf-8 not yet implemented
• CJK charsets
  • ISO-2022-JP
  • ISO-2022-JP-2
  • ISO-2022-KR
  • ISO-2022-CN
  • ISO-2022-CN-EXT

DEC private controls widely supported by emulators

• \033= - DECPAM - application keypad mode
• \033> - DECPNM - normal keypad mode
• \033< - DECANSI - enter ANSI mode
• \033[!p - DECSTR - soft reset
• \033 F - S7C1T - 7-bit controls

ECMA modes

ISO 2022

• 2 - AM - keyboard action mode
• 4 - IRM - insert/replace mode
• 12 - SRM - send/receive mode
• 20 - LNM - linefeed mode

DEC modes

• 1 - CKM - application cursor keys
• 2 - ANM - set VT52 mode
• 3 - COLM - 132-column mode
• 4 - SCLM - smooth scroll
• 5 - SCNM - reverse video mode
• 6 - OM - origin mode
• 7 - AWM - wraparound mode
• 8 - ARM - auto-repeat mode

ECMA attribute sequences

• 0 - NORMAL - normal
• 1 - +BOLD - bold on
• 2 - +DIM - dim on
• 3 - +ITALIC - italic on
• 4 - +UNDERLINE - underline on
• 5 - +BLINK - blink on
• 6 - +FASTBLINK - fastblink on
• 7 - +REVERSE - reverse on
• 8 - +INVISIBLE - invisible on
• 9 - +DELETED - deleted on
• 10 - MAIN-FONT - select primary font
• 11 - ALT-FONT-1 - select alternate font 1
• 12 - ALT-FONT-2 - select alternate font 2
• 13 - ALT-FONT-3 - select alternate font 3
• 14 - ALT-FONT-4 - select alternate font 4
• 15 - ALT-FONT-5 - select alternate font 5
• 16 - ALT-FONT-6 - select alternate font 6
• 17 - ALT-FONT-7 - select alternate font 7
• 18 - ALT-FONT-1 - select alternate font 1
• 19 - ALT-FONT-1 - select alternate font 1
• 20 - FRAKTUR - Fraktur font
• 21 - DOUBLEUNDER - double underline
• 22 - -DIM - dim off
• 23 - -ITALIC - italic off
• 24 - -UNDERLINE - underline off
• 25 - -BLINK - blink off
• 26 - -FASTBLINK - fastblink off
• 27 - -REVERSE - reverse off
• 28 - -INVISIBLE - invisible off
• 29 - -DELETED - deleted off

Init strings

Cap strings

Variable and Function Index

For stty

• BC: tgoto
• ospeed: Output Padding
• PC: Output Padding
• tgetent: Find
• tgetflag: Interrogate
• tgetnum: Interrogate
• tgetstr: Interrogate
• tgoto: tgoto
• tparam: tparam
• tputs: Output Padding
• UP: tgoto

Summary of Capability Names

Here are all the terminal capability names in alphabetical order with a brief description of each. For cross references to their definitions, see the index of capability names.

Variable and Function Index

• BC: tgoto
• ospeed: Output Padding
• PC: Output Padding
• tgetent: Find
• tgetflag: Interrogate
• tgetnum: Interrogate
• tgetstr: Interrogate
• tgoto: tgoto
• tparam: tparam
• tputs: Output Padding
• UP: tgoto

• ae: Standout
• AL: Insdel Line
• al: Insdel Line
• am: Wrapping
• as: Standout
• bc: Cursor Motion
• bl: Bell
• bs: Cursor Motion
• bt: Cursor Motion
• bw: Cursor Motion
• CC: Basic
• cd: Clearing
• ce: Clearing
• ch: Cursor Motion
• cl: Clearing
• CM: Cursor Motion
• cm: Cursor Motion
• co: Screen Size
• cr: Cursor Motion
• cS: Scrolling
• cs: Scrolling
• ct: Initialization
• cv: Cursor Motion
• da: Scrolling
• dB: Pad Specs
• db: Scrolling
• dC: Pad Specs
• DC: Insdel Char
• dc: Insdel Char
• dF: Pad Specs
• DL: Insdel Line
• dl: Insdel Line
• dm: Insdel Char
• dN: Pad Specs
• DO: Cursor Motion
• do: Cursor Motion
• ds: Status Line
• dT: Pad Specs
• ec: Clearing
• ed: Insdel Char
• ei: Insdel Char
• eo: Basic
• es: Status Line
• ff: Cursor Motion
• fs: Status Line
• gn: Basic
• hc: Basic
• hd: Half-Line
• ho: Cursor Motion
• hs: Status Line
• hu: Half-Line
• hz: Basic
• i1: Initialization
• i3: Initialization
• IC: Insdel Char
• ic: Insdel Char
• if: Initialization
• im: Insdel Char
• in: Insdel Char
• ip: Insdel Char
• is: Initialization
• it: Initialization
• K1...K5: Keypad
• k1...k9: Keypad
• kA...kT: Keypad
• ka...ku: Keypad
• km: Meta Key
• l0...l9: Keypad
• LE: Cursor Motion
• le: Cursor Motion
• li: Screen Size
• ll: Cursor Motion
• lm: Scrolling
• LP: Wrapping
• mb: Standout
• md: Standout
• me: Standout
• mh: Standout
• mi: Insdel Char
• mk: Standout
• mm: Meta Key
• mo: Meta Key
• mp: Standout
• mr: Standout
• ms: Underlining
• ms: Standout
• nc: Cursor Motion
• nd: Cursor Motion
• NF: Initialization
• nl: Cursor Motion
• ns: Scrolling
• nw: Cursor Motion
• os: Basic
• pb: Pad Specs
• pc: Pad Specs
• pf: Printer
• pO: Printer
• po: Printer
• ps: Printer
• rc: Cursor Motion
• RI: Cursor Motion
• rp: Basic
• rs: Initialization
• sa: Standout
• sc: Cursor Motion
• se: Standout
• SF: Scrolling
• sf: Scrolling
• sg: Standout
• so: Standout
• SR: Scrolling
• sr: Scrolling
• st: Initialization
• ta: Cursor Motion
• te: Initialization
• ti: Initialization
• ts: Status Line
• uc: Underlining
• ue: Underlining
• ug: Underlining
• ul: Underlining
• UP: Cursor Motion
• up: Cursor Motion
• us: Underlining
• vb: Bell
• ve: Cursor Visibility
• vi: Cursor Visibility
• vs: Cursor Visibility
• wi: Windows
• ws: Status Line
• xb: Basic
• xn: Wrapping
• xs: Standout
• xt: Standout
• xt: Cursor Motion

• Basic: Basic characteristics.
• Screen Size: Screen size, and what happens when it changes.
• Cursor Motion: Various ways to move the cursor.
• Wrapping: What happens if you write a character in the last column.
• Scrolling: Pushing text up and down on the screen.
• Windows: Limiting the part of the window that output affects.
• Clearing: Erasing one or many lines.
• Insdel Line: Making new blank lines in mid-screen; deleting lines.
• Insdel Char: Inserting and deleting characters within a line.
• Standout: Highlighting some of the text.
• Underlining: Underlining some of the text.
• Cursor Visibility: Making the cursor more or less easy to spot.
• Bell: Attracts user's attention; not localized on the screen.
• Keypad: Recognizing when function keys or arrows are typed.
• Meta Key: META acts like an extra shift key.
• Initialization: Commands used to initialize or reset the terminal.
• Pad Specs: Info for the kernel on how much padding is needed.
• Status Line: A status line displays background information.
• Half-Line: Moving by half-lines, for superscripts and subscripts.
• Printer: Controlling auxiliary printers of display terminals.

Translated Term Capabilities

This is helpful so you can understand what a term cap does, by looking at the long name.

List of All Terminals

You can view this list with the following command:

$ toe -a|sort -d

VT100 keypad Diagram

VT100 LINK

Here's a diagram of the VT100 keypad keys with their bindings. The top line is the name of the key (some DEC keyboards have the keys labelled somewhat differently, like GOLD instead of PF1, but this is the most "official" name). The second line is the escape sequence it generates in Application Keypad mode (where "$" means the ESC character). The third line contains two items, first the mapping of the key in terminfo, and then in termcap.

   _______________________________________
  |   PF1   |   PF2   |   PF3   |   PF4   |
  |   $OP   |   $OQ   |   $OR   |   $OS   |
  |_kf1__k1_|_kf2__k2_|_kf3__k3_|_kf4__k4_|
  |    7         8         9         -    |
  |   $Ow   |   $Ox   |   $Oy   |   $Om   |
  |_kf9__k9_|_kf10_k;_|_kf0__k0_|_________|
  |    4    |    5    |    6    |    ,    |
  |   $Ot   |   $Ou   |   $Ov   |   $Ol   |
  |_kf5__k5_|_kf6__k6_|_kf7__k7_|_kf8__k8_|
  |    1    |    2    |    3    |         |
  |   $Oq   |   $Or   |   $Os   |  enter  |
  |_ka1__K1_|_kb2__K2_|_ka3__K3_|  $OM    |
  |         0         |   .     |         |
  |        $Op        |  $On    |         |
  |___kc1_______K4____|_kc3__K5_|_kent_@8_|

A better adaptation to modern keyboards such as the PC's, which have a dozen function keys and the keypad 2,4,6,8 keys are labeled with arrows keys, is to use the 5-key arrangement to model the arrow keys as suggested in the terminfo guidelines:

   _______________________________________
  |   PF1   |   PF2   |   PF3   |   PF4   |
  |   $OP   |   $OQ   |   $OR   |   $OS   |
  |_kf1__k1_|_kf2__k2_|_kf3__k3_|_kf4__k4_|
  |    7         8         9         -    |
  |   $Ow   |   $Ox   |   $Oy   |   $Om   |
  |_ka1__K1_|_________|_ka3__K3_|_________|
  |    4    |    5    |    6    |    ,    |
  |   $Ot   |   $Ou   |   $Ov   |   $Ol   |
  |_________|_kb2__K2_|_________|_________|
  |    1    |    2    |    3    |         |
  |   $Oq   |   $Or   |   $Os   |  enter  |
  |_kc1__K4_|_________|_kc3__K5_|  $OM    |
  |         0         |   .     |         |
  |        $Op        |  $On    |         |
  |___________________|_________|_kent_@8_|

SGR parameter values

Sequence     Sequence                             Parameter   or
Mnemonic     Name              Sequence           Value      Mode   terminfo
-----------------------------------------------------------------------------
APC  Applicatn Program Command \E _                -         Delim  -
BEL  Bell *                    ^G                  -         -      bel
BPH  Break Permitted Here *    \E B                -         *      -
BS   Backpace *                ^H                  -         EF     -
CAN  Cancel *                  ^X                  -         -      -   (A)
CBT  Cursor Backward Tab       \E [ Pn Z           1         eF     cbt
CCH  Cancel Previous Character \E T                -         -      -
CHA  Cursor Horizntal Absolute \E [ Pn G           1         eF     hpa (B)
CHT  Cursor Horizontal Tab     \E [ Pn I           1         eF     tab (C)
CMD  Coding Method Delimiter * \E
CNL  Cursor Next Line          \E [ Pn E           1         eF     nel (D)
CPL  Cursor Preceding Line     \E [ Pn F           1         eF     -
CPR  Cursor Position Report    \E [ Pn ; Pn R      1, 1      -      -   (E)
CSI  Control Sequence Intro    \E [                -         Intro  -
CTC  Cursor Tabulation Control \E [ Ps W           0         eF     -   (F)
CUB  Cursor Backward           \E [ Pn D           1         eF     cub
CUD  Cursor Down               \E [ Pn B           1         eF     cud
CUF  Cursor Forward            \E [ Pn C           1         eF     cuf
CUP  Cursor Position           \E [ Pn ; Pn H      1, 1      eF     cup (G)
CUU  Cursor Up                 \E [ Pn A           1         eF     cuu
CVT  Cursor Vertical Tab       \E [ Pn Y           -         eF     -   (H)
DA   Device Attributes         \E [ Pn c           0         -      -
DAQ  Define Area Qualification \E [ Ps o           0         -      -
DCH  Delete Character          \E [ Pn P           1         eF     dch
DCS  Device Control String     \E P                -         Delim  -
DL   Delete Line               \E [ Pn M           1         eF     dl
DLE  Data Link Escape *        ^P                  -         -      -
DMI  Disable Manual Input      \E \                -         Fs     -
DSR  Device Status Report      \E [ Ps n           0         -      -   (I)
DTA  Dimension Text Area *     \E [ Pn ; Pn SPC T  -         PC     -
EA   Erase in Area             \E [ Ps O           0         eF     -   (J)
ECH  Erase Character           \E [ Pn X           1         eF     ech
ED   Erase in Display          \E [ Ps J           0         eF     ed  (J)
EF   Erase in Field            \E [ Ps N           0         eF     -
EL   Erase in Line             \E [ Ps K           0         eF     el  (J)
EM   End of Medium *           ^Y                  -         -      -
EMI  Enable Manual Input       \E b                          Fs     -
ENQ  Enquire                   ^E                  -         -      -
EOT  End Of Transmission       ^D                  -         *      -
EPA  End of Protected Area     \E W                -         -      -   (K)
ESA  End of Selected Area      \E G                -         -      -
ESC  Escape                    ^[                  -         -      -
ETB  End Transmission Block    ^W                  -         -      -
ETX  End of Text               ^C                  -         -      -
FF   Form Feed                 ^L                  -         -      -
FNK  Function Key *            \E [ Pn SPC W       -         -      -
GCC  Graphic Char Combination* \E [ Pn ; Pn SPC B  -         -      -
FNT  Font Selection            \E [ Pn ; Pn SPC D  0, 0      FE     -
GSM  Graphic Size Modify       \E [ Pn ; Pn SPC B  100, 100  FE     -   (L)
GSS  Graphic Size Selection    \E [ Pn SPC C       none      FE     -
HPA  Horz Position Absolute    \E [ Pn `           1         FE     -   (B)
HPB  Char Position Backward    \E [ j              1         FE     -
HPR  Horz Position Relative    \E [ Pn a           1         FE     -   (M)
HT   Horizontal Tab *          ^I                  -         FE     -   (N)
HTJ  Horz Tab w/Justification  \E I                -         FE     -
HTS  Horizontal Tab Set        \E H                -         FE     hts
HVP  Horz & Vertical Position  \E [ Pn ; Pn f      1, 1      FE     -   (G)
ICH  Insert Character          \E [ Pn @           1         eF     ich
IDCS ID Device Control String  \E [ SPC O          -         *      -
IGS  ID Graphic Subrepertoire  \E [ SPC M          -         *      -
IL   Insert Line               \E [ Pn L           1         eF     il
IND  Index                     \E D                -         FE     -
INT  Interrupt                 \E a                -         Fs     -
JFY  Justify                   \E [ Ps SPC F       0         FE     -
IS1  Info Separator #1 *       ^_                  -         *      -
IS2  Info Separator #1 *       ^^                  -         *      -
IS3  Info Separator #1 *       ^]                  -         *      -
IS4  Info Separator #1 *       ^\                  -         *      -
LF   Line Feed                 ^J                  -         -      -
LS1R Locking Shift Right 1 *   \E ~                -         -      -
LS2  Locking Shift 2 *         \E n                -         -      -
LS2R Locking Shift Right 2 *   \E }                -         -      -
LS3  Locking Shift 3 *         \E o                -         -      -
LS3R Locking Shift Right 3 *   \E |                -         -      -
MC   Media Copy                \E [ Ps i           0         -      -   (S)
MW   Message Waiting           \E U                -         -      -
NAK  Negative Acknowledge *    ^U                  -         *      -
NBH  No Break Here *           \E C                -         -      -
NEL  Next Line                 \E E                -         FE     nel (D)
NP   Next Page                 \E [ Pn U           1         eF     -
NUL  Null *                    ^@                  -         -      -
OSC  Operating System Command  \E ]                -         Delim  -
PEC  Pres. Expand/Contract *   \E Pn SPC Z         0         -      -
PFS  Page Format Selection *   \E Pn SPC J         0         -      -
PLD  Partial Line Down         \E K                -         FE     -   (T)
PLU  Partial Line Up           \E L                -         FE     -   (U)
PM   Privacy Message           \E ^                -         Delim  -
PP   Preceding Page            \E [ Pn V           1         eF     -
PPA  Page Position Absolute *  \E [ Pn SPC P       1         FE     -
PPB  Page Position Backward *  \E [ Pn SPC R       1         FE     -
PPR  Page Position Forward *   \E [ Pn SPC Q       1         FE     -
PTX  Parallel Texts *          \E [ \              -         -      -
PU1  Private Use 1             \E Q                -         -      -
PU2  Private Use 2             \E R                -         -      -
QUAD Typographic Quadding      \E [ Ps SPC H       0         FE     -
REP  Repeat Char or Control    \E [ Pn b           1         -      rep
RI   Reverse Index             \E M                -         FE     -   (V)
RIS  Reset to Initial State    \E c                -         Fs     -
RM   Reset Mode *              \E [ Ps l           -         -      -   (W)
SACS Set Add. Char. Sep. *     \E [ Pn SPC /       0         -      -
SAPV Sel. Alt. Present. Var. * \E [ Ps SPC ]       0         -      -   (X)
SCI  Single-Char Introducer    \E Z                -         -      -
SCO  Sel. Char. Orientation *  \E [ Pn ; Pn SPC k  -         -      -
SCS  Set Char. Spacing *       \E [ Pn SPC g       -         -      -
SD   Scroll Down               \E [ Pn T           1         eF     rin
SDS  Start Directed String *   \E [ Pn ]           1         -      -
SEE  Select Editing Extent     \E [ Ps Q           0         -      -   (Y)
SEF  Sheet Eject & Feed *  \E [ Ps ; Ps SPC Y  0,0       -      -
SGR  Select Graphic Rendition  \E [ Ps m           0         FE     sgr (O)
SHS  Select Char. Spacing *    \E [ Ps SPC K       0         -      -
SI   Shift In                  ^O                  -         -      -   (P)
SIMD Sel. Imp. Move Direct. *  \E [ Ps ^           -         -      -
SL   Scroll Left               \E [ Pn SPC @       1         eF     -
SLH  Set Line Home *           \E [ Pn SPC U       -         -      -
SLL  Set Line Limit *          \E [ Pn SPC V       -         -      -
SLS  Set Line Spacing *        \E [ Pn SPC h       -         -      -
SM   Select Mode               \E [ Ps h           none      -      -   (W)
SO   Shift Out                 ^N                  -         -      -   (Q)
SOH  Start Of Heading *        ^A                  -         -      -
SOS  Start of String *         \E X                -         -      -
SPA  Start of Protected Area   \E V                -         -      -   (Z)
SPD  Select Pres. Direction *  \E [ Ps ; Ps SPC S  0,0       -      -
SPH  Set Page Home *           \E [ Ps SPC G       -         -      -
SPI  Spacing Increment         \E [ Pn ; Pn SPC G  none      FE     -
SPL  Set Page Limit *          \E [ Ps SPC j       -         -      -
SPQR Set Pr. Qual. & Rapid. *  \E [ Ps SPC X       0         -      -
SR   Scroll Right              \E [ Pn SPC A       1         eF     -
SRCS Set Reduced Char. Sep. *  \E [ Pn SPC f       0         -      -
SRS  Start Reversed String *   \E [ Ps [           0         -      -
SSA  Start of Selected Area    \E F                -         -      -
SSU  Select Size Unit *        \E [ Pn SPC I       0         -      -
SSW  Set Space Width *         \E [ Pn SPC [       none      -      -
SS2  Single Shift 2 (G2 set)   \E N                -         Intro  -
SS3  Single Shift 3 (G3 set)   \E O                -         Intro  -
ST   String Terminator         \E \                -         Delim  -
STAB Selective Tabulation *    \E [ Pn SPC ^       -         -      -
STS  Set Transmit State        \E S                -         -      -
STX  Start pf Text *           ^B                  -         -      -
SU   Scroll Up                 \E [ Pn S           1         eF     indn
SUB  Substitute *              ^Z                  -         -      -
SVS  Select Line Spacing *     \E [ Pn SPC \       1         -      -
SYN  Synchronous Idle *        ^F                  -         -      -
TAC  Tabul. Aligned Centered * \E [ Pn SPC b       -         -      -
TALE Tabul. Al. Leading Edge * \E [ Pn SPC a       -         -      -
TATE Tabul. Al. Trailing Edge* \E [ Pn SPC `       -         -      -
TBC  Tab Clear                 \E [ Ps g           0         FE     tbc
TCC  Tabul. Centered on Char * \E [ Pn SPC c       -         -      -
TSR  Tabulation Stop Remove  * \E [ Pn SPC d       -         FE     -
TSS  Thin Space Specification  \E [ Pn SC E        none      FE     -
VPA  Vert. Position Absolute   \E [ Pn d           1         FE     vpa
VPB  Line Position Backward *  \E [ Pn k           1         FE     -
VPR  Vert. Position Relative   \E [ Pn e           1         FE     -   (R)
VPR  Vert. Position Relative   \E [ Pn e           1         FE     -   (R)
VT   Vertical Tabulation *     ^K                  -         FE     -
VTS  Vertical Tabulation Set   \E J                -         FE     -

Basic Characteristics

This section documents the capabilities that describe the basic and nature of the terminal, and also those that are relevant to the output of graphic characters.

7bit vs. 8bit

These recommendations are optional. IBCS2 allows the leading escape to # be either the 7-bit \E[ or 8-bit \0233 introducer, in accordance with # the ANSI X.364/ISO 6429/ECMA-48 standard.

1.6.1 Describing the Encoding

For example, the cm string for a standard ANSI terminal is written as \E[%i%d;%dH. (\E stands for .) cm by convention always requires two parameters, the vertical and horizontal goal positions, so this string specifies the encoding of two parameters. Here %i increments the two values supplied, and each %d encodes one of the values in decimal. If the cursor position values 20,58 are encoded with this string, the result is \E[21;59H.

First, here are the %-sequences that generate output. Except for %%, each of them encodes one parameter and advances the pointer to the following parameter.

• %% Output a single %. This is the only way to represent a literal % in a terminal command with parameters. %% does not use up a parameter.
• %d As in printf, output the next parameter in decimal.
• %2 Like %02d in printf: output the next parameter in decimal, and always use at least two digits.
• %3 Like %03d in printf: output the next parameter in decimal, and always use at least three digits. Note that %4 and so on are _not_ defined.
• %. Output the next parameter as a single character whose ASCII code is the parameter value. Like %c in printf.
• %+CHAR Add the next parameter to the character CHAR, and output the resulting character. For example, %+ represents 0 as a space, 1 as !, etc.

The following %-sequences specify alteration of the parameters (their values, or their order) rather than encoding a parameter for output. They generate no output; they are used only for their side effects on the parameters. Also, they do not advance the "next parameter" pointer except as explicitly stated. Only %i, %r and %> are defined in standard Unix termcap. The others are GNU extensions.

• %i Increment the next two parameters. This is used for terminals that expect cursor positions in origin 1. For example, %i%d,%d would output two parameters with 1 for 0, 2 for 1, etc.
• %r Interchange the next two parameters. This is used for terminals whose cursor positioning command expects the horizontal position first.
• %s Skip the next parameter. Do not output anything.
• %b Back up one parameter. The last parameter used will become once again the next parameter to be output, and the next output command will use it. Using %b more than once, you can back up any number of parameters, and you can refer to each parameter any number of times.
• %>C1C2 Conditionally increment the next parameter. Here C1 and C2 are characters which stand for their ASCII codes as numbers. If the next parameter is greater than the ASCII code of C1, the ASCII code of C2 is added to it.
• %a OP TYPE POS Perform arithmetic on the next parameter, do not use it up, and do not output anything. Here OP specifies the arithmetic operation, while TYPE and POS together specify the other operand.

Spaces are used above to separate the operands for clarity; the spaces don't appear in the data base, where this sequence is exactly five characters long. The character OP says what kind of arithmetic operation to perform. It can be any of these characters:

• = - assign a value to the next parameter, ignoring its old value. The new value comes from the other operand.
• + - add the other operand to the next parameter.
• - - subtract the other operand from the next parameter.
• * - multiply the next parameter by the other operand.
• / - divide the next parameter by the other operand.

The "other operand" may be another parameter's value or a constant; the character TYPE says which. It can be:

• p - Use another parameter. The character POS says which parameter to use. Subtract 64 from its ASCII code to get the position of the desired parameter relative to this one. Thus, the character A as POS means the parameter after the next one; the character ? means the parameter before the next one.
• c - Use a constant value. The character POS specifies the value of the constant. The 0200 bit is cleared out, so that 0200 can be used to represent zero.

The following %-sequences are special purpose hacks to compensate for the weird designs of obscure terminals. They modify the next parameter or the next two parameters but do not generate output and do not use up any parameters. %m is a GNU extension; the others are defined in standard Unix termcap.

• %n - Exclusive-or the next parameter with 0140, and likewise the parameter after next.
• %m - Complement all the bits of the next parameter and the parameter after next.
• %B - Encode the next parameter in BCD. It alters the value of the parameter by adding six times the quotient of the parameter by ten. Here is a C statement that shows how the new value is computed: PARM = (PARM / 10) * 16 + PARM % 10;
• %D - Transform the next parameter as needed by Delta Data terminals. This involves subtracting twice the remainder of the parameter by 16. PARM -= 2 * (PARM % 16);

Terminal Type Name Conventions

Here is a list of standard suffixes and their conventional meanings:

• -w - Short for "wide". This is a mode that gives the terminal more columns than usual. This is normally a user option.
• -am - "Automatic margins". This is an alternate description for use when the terminal's margin-wrap switch is on; it contains the am flag. The implication is that normally the switch is off and the usual description for the terminal says that the switch is off.
• -nam - "No automatic margins". The opposite of -am, this names an alternative description which lacks the am flag. This implies that the terminal is normally operated with the margin-wrap switch turned on, and the normal description of the terminal says so.
• -na - "No arrows". This terminal description initializes the terminal to keep its arrow keys in local mode. This is a user option.
• -rv - "Reverse video". This terminal description causes text output for normal video to appear as reverse, and text output for reverse video to come out as normal. Often this description differs from the usual one by interchanging the two strings which turn reverse video on and off.

This is a user option; you can choose either the "reverse video" variant terminal type or the normal terminal type, and termcap will obey.

• -s - "Status". Says to enable use of a status line which ordinary output does not touch (*note Status Line::).

Some terminals have a special line that is used only as a status line. For these terminals, there is no need for an -s variant; the status line commands should be defined by default. On other terminals, enabling a status line means removing one screen line from ordinary use and reducing the effective screen height. For these terminals, the user can choose the -s variant type to request use of a status line.

• -NLINES - Says to operate with NLINES lines on the screen, for terminals such as the Ambassador which provide this as an option. Normally this is a user option; by choosing the terminal type, you control how many lines termcap will use.
• -NPAGESp - Says that the terminal has NPAGES pages worth of screen memory, for terminals where this is a hardware option.
• -unk - Says that description is not for direct use, but only for reference in tc capabilities. Such a description is a kind of subroutine, because it describes the common characteristics of several variant descriptions that would use other suffixes in place of -unk.

MS-DOS ANSI.SYS

Here is a description of the color and attribute controls supported in the ANSI.SYS driver under MS-DOS. Most console drivers and ANSI terminal emulators for Intel boxes obey these. They are a proper subset of the ECMA-48 escapes.

Bright black becomes gray, bright brown becomes yellow. These coincide with the prescriptions of the ISO 6429/ECMA-48 standard. * If the 5 attribute is on and you set a background color (40-47) it is supposed to enable bright background.

0        all attributes off
1        foreground bright
4        underscore on
5        blink on/background bright (not reliable with brown)
7        reverse-video
8        set blank (non-display)
10       set primary font
11       set first alternate font (on PCs, display ROM characters 1-31)
12       set second alternate font (on PCs, display IBM high-half chars)
3n       set foreground color       / 0=black, 1=red,     2=green, 3=brown,
4n       set background color       \ 4=blue,  5=magenta, 6=cyan,  7=white

STTY

Stty Control Settings

Stty Input settings

Stty Output settings

These arguments specify output-related operations.

Stty Local settings

Stty Combination settings

cread -ignbrk brkint -inlcr -igncr icrnl -ixoff -iuclc -ixany imaxbel opost -olcuc -ocrnl onlcr -onocr -onlret -ofill -ofdel nl0 cr0 tab0 bs0 vt0 ff0 isig icanon iexten echo echoe echok -echonl -noflsh -xcase -tostop -echoprt echoctl echoke

-ignbrk -brkint -ignpar -parmrk -inpck -istrip -inlcr -igncr -icrnl -ixon -ixoff -iuclc -ixany -imaxbel -opost -isig -icanon -xcase min 1 time 0

Special characters

The special characters' default values vary from system to system. They are set with the syntax name value, where the names are listed below and the value can be given either literally, in hat notation (^C), or as an integer which may start with 0x to indicate hexadecimal, 0 to indicate octal, or any other digit to indicate decimal.

For GNU stty, giving a value of ^- or undef disables that special character. (This is incompatible with Ultrix stty, which uses a value of u to disable a special character. GNU stty treats a value u like any other, namely to set that special character to .)

Special settings

• min N - Set the minimum number of characters that will satisfy a read until the time value has expired, when -icanon is set.
• time N - Set the number of tenths of a second before reads time out if the minimum number of characters have not been read, when -icanon is set.
• ispeed N - Set the input speed to N.
• ospeed N - Set the output speed to N.
• rows N - Tell the tty kernel driver that the terminal has N rows. Non-POSIX.
• cols N, columns N - Tell the kernel that the terminal has N columns. Non-POSIX.
• size - Print the number of rows and columns that the kernel thinks the terminal has. (Systems that don't support rows and columns in the kernel typically use the environment variables LINES and COLUMNS instead; however, GNU stty does not know anything about them.) Non-POSIX.
• line N - Use line discipline N. Non-POSIX.
• speed - Print the terminal speed.
• N - Set the input and output speeds to N. N can be one of: 0 50 75 110 134 134.5 150 200 300 600 1200 1800 2400 4800 9600 19200 38400 exta extb. exta is the same as 19200; extb is the same as 38400. 0 hangs up the line if -clocal is set.

Color Terminals

color256 ()
{
    local L=$(sed 's/[0-9]//g; s/./#/g' <<<`seq -s+0 $(($COLUMNS - 10))`);
    for i in `seq 0 $(tput colors)`;
    do printf " %.3d `tput setab $i`${L}${R} %.3d `tput setab 0;tput setaf 7`\n" $i $i | tr '#' ' ';
    done
}

for F in `find ~/.terminfo/ -type f | sed 's/^.*\///' | xargs -P0 -I'TT' sh -c 'echo "$(tput -T TT colors): TT"'|sed '/^-/d'| grep ^16:|cut -d: -f2`; do
echo -e "\n\n";
pm $F; export TERM=$F; tput -T $F initc; color256; done

find ~/.terminfo/ -type f | sed 's/^.*\///' | xargs -I'TT' sh -c 'echo "$(tput -T TT colors): TT"'|sed '/^-/d'

Terminals with 16 Colors

• aixterm-16color
• amiga-vnc
• hp2397
• hp2397a
• hp+color
• ibm+16color
• konsole-16color
• nsterm-16color
• nsterm-7-c
• nsterm-7-c-s
• nsterm-acs-c
• nsterm-acs-c-s
• nsterm-c
• nsterm+c
• nsterm-c-7
• nsterm-c-acs
• nsterm-c-s
• nsterm-c-s-7
• nsterm-c-s-acs
• rxvt-16color
• screen-16color
• screen-16color-bce
• screen-16color-bce-s
• screen-16color-s
• xterm-16color

Terminals with 52 Colors

• d430c-dg-ccc
• d430c-unix-25-ccc
• d430c-unix-ccc
• d430c-unix-s-ccc
• d430c-unix-sr-ccc
• d430c-unix-w-ccc
• d430-dg-ccc
• d430-unix-25-ccc
• d430-unix-ccc
• d430-unix-s-ccc
• d430-unix-sr-ccc
• d430-unix-w-ccc
• dg+ccc
• dgunix+ccc

Terminals with 64 Colors

• hpterm-color
• wy370
• wy370-101k
• wy370-105k
• wy370-EPC
• wy370-nk
• wy370-rv
• wy370-vb
• wy370-w
• wy370-wvb
• wyse370
• Eterm-88color
• rxvt-88color
• xterm-88color
• xterm+88color

Terminals with 256 colors

• Eterm-256color
• gnome-256color
• konsole-256color
• putty-256color
• rxvt-256color
• screen-256color
• screen-256color-bce
• screen-256color-bce-s
• screen-256color-s
• xterm-256color
• xterm+256color

View All tput capabilities

http://blogs.msdn.com/adioltean/articles/271063.aspx

function tputs(){ infocmp -1|sed 's/^[   ]*//; /=/!d; s/=.*//g; /[#\|]/d'; }

Some common terminfo parameter sequences, their termcap equivalents, and some terminal types which commonly have such sequences, are:

terminfo                    termcap   Representative Terminals
---------------------------------------------------------------
%p1%c                       %.        adm
%p1%d                       %d        hp, ANSI standard, vt100
%p1%+%c                 %+x       concept
%i                          %iq       ANSI standard, vt100
%p1%?%>%t%p1%+%;    %>xy      concept
%p2 is printed before %p1   %r        hp

Installing your Own Terminfo

MostLike, or if that is offline I uploaded a copy: mostlike - manpages with color looking like most

rm -rvf ~/.terminfo
mkdir -pv ~/.terminfo
curl -o terminfo.master http://nion.modprobe.de/mostlike.txt; curl -Ss ftp://invisible-island.net/ncurses/terminfo.src.gz
export TERMINFO=~/.terminfo;
sudo tic -e screen-256color,screen-256color-s,screen-256color-bce,screen-256color-bce-s,xterm+256color,xterm,xterm-pcolor terminfo.src

256 Colors in Terminal

256 Colors (Background)

W=`tput setaf 7` RC="\E[0;0;0m" L=$(sed 's/[0-9]//g; s/./ /g' <<<`seq -s+0 $(($COLUMNS/2))`);
 
for i in `seq 0 256`;
do
  printf "${W}\n%.3d `tput setab $i`${L}${RC}" $i;
done

256 Colors (Foreground)

W=`tput setaf 7` WB=`tput setab 0` RC="\E[0;0;0m" L=$(sed 's/[0-9]//g; s/./#/g' <<<`seq -s+0 $(($COLUMNS/2))`);
for i in `seq 0 256`;
do
  printf "${WB}\n%.3d `tput setaf $i`${L}${RC}" $i;
done

Terminal Capabilities - Infocmp

infocmp -1Lq|grep -v "$TERM\|#"|tr -d '  '

DEC/ANSI special sequences

List of the DEC/ANSI special sequences recognized:

Term Sorted

./MKtermsort.sh |sed 's/.*\/\*  \(.*\)  \*\//\1/g'|sort -u|grep ^[a-zA-Z]|sortwc|grep -v ^static|sort -d|tr " " ','|sed 's/\([^,]\{1,\}\),/<var>\1<\/var>,/g'

AB,ac,acs_btee,acsc,acs_chars,acs_hline,acs_llcorner,acs_lrcorner,acs_ltee,acs_plus,acs_rtee,acs_ttee,acs_ulcorner,acs_urcorner,acs_vline,ae,AF,al,AL,alt_scancode_esc,am,apstr,arrow_key_map,as,auto_left_margin,auto_right_margin,back_color_erase,backspace_delay,backspace_if_not_bs,backspaces_with_bs,back_tab,batt1,batt2,bc,bce,bel,bell,bicr,binel,birep,bit_image_carriage_return,bit_image_entwining,bit_image_newline,bit_image_repeat,bit_image_type,bitwin,bitype,bl,blink,bold,box1,box2,box_chars_1,bs,bt,BT,btml,btns,buffer_capacity,bufsz,buttons,bw,bx,can_change,carriage_return,carriage_return_delay,cb,cbt,cc,CC,ccc,cd,ce,ceol_standout_glitch,ch,change_char_pitch,change_line_pitch,change_res_horz,change_res_vert,change_scroll_region,char_padding,char_set_names,chr,chts,ci,civis,cl,clear,clear_all_tabs,clear_margins,clear_screen,clr_bol,clr_eol,clr_eos,cm,CM,cmdch,cnorm,co,Co,code_set_init,col_addr_glitch,colb0,colb1,colb2,colb3,colb4,colb5,colb6,colb7,colf0,colf1,colf2,colf3,colf4,colf5,colf6,colf7,color_names,colornm,colors,cols,column_address,columns,command_character,cpi,cpi_changes_res,cpix,cps,cr,cr_cancels_micro_mode,create_window,crt_no_scrolling,crxm,cs,csin,csnm,csr,ct,cub,cub1,cud,cud1,cuf,cuf1,cup,cursor_address,cursor_down,cursor_home,cursor_invisible,cursor_left,cursor_mem_address,cursor_normal,cursor_right,cursor_to_ll,cursor_up,cursor_visible,cuu,cuu1,cv,cvr,cvvis,CW,cwin,da,daisy,db,dB,dc,dC,DC,dch,dch1,dclk,defbi,defc,define_bit_image_region,define_char,delete_character,delete_line,dest_tabs_magic_smso,device_type,devt,DI,dial,dial_phone,dim,dispc,display_clock,display_pc_char,dis_status_line,DK,dl,DL,dl1,dm,dN,do,DO,docr,dot_horz_spacing,dot_vert_spacing,down_half_line,ds,dsl,dT,dv,eA,eat_newline_glitch,ec,ech,ed,ehhlm,ei,el,el1,elhlm,elohlm,ena_acs,enacs,endbi,end_bit_image_region,enter_alt_charset_mode,enter_am_mode,enter_blink_mode,enter_bold_mode,enter_ca_mode,enter_delete_mode,enter_dim_mode,enter_doublewide_mode,enter_draft_quality,enter_horizontal_hl_mode,enter_insert_mode,enter_italics_mode,enter_left_hl_mode,enter_leftward_mode,enter_low_hl_mode,enter_micro_mode,enter_near_letter_quality,enter_normal_quality,enter_pc_charset_mode,enter_protected_mode,enter_reverse_mode,enter_right_hl_mode,enter_scancode_mode,enter_secure_mode,enter_shadow_mode,enter_standout_mode,enter_subscript_mode,enter_superscript_mode,enter_top_hl_mode,enter_underline_mode,enter_upward_mode,enter_vertical_hl_mode,enter_xon_mode,eo,erase_chars,erase_overstrike,erhlm,es,eslok,ethlm,evhlm,exit_alt_charset_mode,exit_am_mode,exit_attribute_mode,exit_ca_mode,exit_delete_mode,exit_doublewide_mode,exit_insert_mode,exit_italics_mode,exit_leftward_mode,exit_micro_mode,exit_pc_charset_mode,exit_scancode_mode,exit_shadow_mode,exit_standout_mode,exit_subscript_mode,exit_superscript_mode,exit_underline_mode,exit_upward_mode,exit_xon_mode,F1,F2,F3,F4,F5,F6,F7,F8,F9,Fa,FA,Fb,FB,Fc,FC,Fd,FD,Fe,FE,ff,Ff,FF,Fg,FG,fh,Fh,FH,Fi,FI,fixed_pause,Fj,FJ,Fk,FK,Fl,FL,flash,flash_hook,flash_screen,fln,Fm,FM,Fn,FN,Fo,FO,font0,font1,font2,font3,font4,font5,font6,font7,form_feed,Fp,FP,Fq,FQ,Fr,FR,from_status_line,fs,FS,fsl,FT,FU,FV,FW,FX,FY,FZ,G1,G2,G3,G4,GC,GD,generic_type,getm,get_mouse,GH,GL,Gm,gn,gnu_has_meta_key,goto_window,GR,GU,GV,hangup,hard_copy,hard_cursor,has_hardware_tabs,has_meta_key,has_print_wheel,has_status_line,hc,HC,hd,hl,hls,ho,home,hook,horizontal_tab_delay,hpa,hs,ht,hts,hu,HU,hue_lightness_saturation,hup,hz,i1,i2,i3,ic,Ic,IC,ich,ich1,if,il,il1,im,in,ind,indn,init_1string,init_2string,init_3string,initc,init_file,initialize_color,initial ize_pair,initp,init_prog,init_tabs,insert_character,insert_line,insert_null_glitch,insert_padding,invis,ip,iP,Ip,iprog,is,is1,is2,is3,it,k;,k0,k1,K1,k2,K2,k3,K3,k4,K4,k5,K5,k6,k7,k8,k9,ka,kA,ka1,ka3,kact,kb,kB,kb2,kbeg,kBEG,kbs,kbtab,kC,kc1,kc3,kcan,kCAN,kcbt,kclo,kclr,kcmd,kCMD,kcpn,kcpy,kCPY,kcrt,kCRT,kctab,kcub1,kcud1,kcuf1,kcuu1,kd,kD,kDC,kdch1,kDL,kdl1,kdo,ke,kE,ked,kel,kend,kEND,kent,kEOL,kext,kEXT,key_a1,key_a3,key_b2,key_backspace,key_beg,key_btab,key_c1,key_c3,key_cancel,key_catab,key_clear,key_close,key_command,key_copy,key_create,key_ctab,key_dc,key_dl,key_down,key_eic,key_end,key_enter,key_eol,key_eos,key_exit,key_f0,key_f1,key_f10,key_f11,key_f12,key_f13,key_f14,key_f15,key_f16,key_f17,key_f18,key_f19,key_f2,key_f20,key_f21,key_f22,key_f23,key_f24,key_f25,key_f26,key_f27,key_f28,key_f29,key_f3,key_f30,key_f31,key_f32,key_f33,key_f34,key_f35,key_f36,key_f37,key_f38,key_f39,key_f4,key_f40,key_f41,key_f42,key_f43,key_f44,key_f45,key_f46,key_f47,key_f48,key_f49,key_f5,key_f50,key_f51,key_f52,key_f53,key_f54,key_f55,key_f56,key_f57,key_f58,key_f59,key_f6,key_f60,key_f61,key_f62,key_f63,key_f7,key_f8,key_f9,key_find,key_help,key_home,key_ic,key_il,key_left,key_ll,key_mark,key_message,key_mouse,key_move,key_next,key_npage,key_open,key_options,keypad_local,keypad_xmit,key_ppage,key_previous,key_print,key_redo,key_reference,key_refresh,key_replace,key_restart,key_resume,key_right,key_save,key_sbeg,key_scancel,key_scommand,key_scopy,key_screate,key_sdc,key_sdl,key_select,key_send,key_seol,key_sexit,key_sf,key_sfind,key_shelp,key_shome,key_sic,key_sleft,key_smessage,key_smove,key_snext,key_soptions,key_sprevious,key_sprint,key_sr,key_sredo,key_sreplace,key_sright,key_srsume,key_ssave,key_ssuspend,key_stab,key_sundo,key_suspend,key_undo,key_up,kF,kf0,kf1,kf10,kf11,kf12,kf13,kf14,kf15,kf16,kf17,kf18,kf19,kf2,kf20,kf21,kf22,kf23,kf24,kf25,kf26,kf27,kf28,kf29,kf3,kf30,kf31,kf32,kf33,kf34,kf35,kf36,kf37,kf38,kf39,kf4,kf40,kf41,kf42,kf43,kf44,kf45,kf46,kf47,kf48,kf49,kf5,kf50,kf51,kf52,kf53,kf54,kf55,kf56,kf57,kf58,kf59,kf6,kf60,kf61,kf62,kf63,kf7,kf8,kf9,kfnd,kFND,kh,kH,khlp,kHLP,kHOM,khome,khts,kI,kIC,kich1,kil1,kind,kl,kL,kLFT,kll,km,kM,Km,kmous,kmov,kMOV,kmpf1,kmpf2,kmpf3,kmpf4,kmpf5,kmpf6,kmpf7,kmpf8,kmpf9,kmpt1,kmpt2,kmpt3,kmpt4,kmpt5,kmpt6,kmpt7,kmpt8,kmpt9,kmrk,kmsg,kMSG,kn,kN,knl,knp,knpn,knxt,kNXT,ko,kopn,kopt,kOPT,kP,kpp,kppn,kprt,kPRT,kprv,kPRV,kquit,kr,kR,krdo,kRDO,kref,kres,kRES,krfr,kri,kRIT,krmir,krpl,kRPL,krst,ks,kS,ksav,kSAV,kscl,kscr,ksel,ksf1,ksf10,ksf2,ksf3,ksf4,ksf5,ksf6,ksf7,ksf8,ksf9,kslt,kspd,kSPD,kt,kT,ktab,ktbc,ku,kund,kUND,l0,l1,l2,l3,l4,l5,l6,l7,l8,l9,la,label_format,label_height,label_off,label_on,label_width,lab_f0,lab_f1,lab_f10,lab_f2,lab_f3,lab_f4,lab_f5,lab_f6,lab_f7,lab_f8,lab_f9,le,LE,Lf,LF,lf0,lf1,lf10,lf2,lf3,lf4,lf5,lf6,lf7,lf8,lf9,lh,li,linefeed_if_not_lf,linefeed_is_newline,lines,lines_of_memory,ll,lm,LO,lpi,lpi_changes_res,lpix,lvert,lw,ma,maddr,magic_cookie_glitch,magic_cookie_glitch_ul,max_attributes,max_colors,maximum_windows,max_micro_address,max_micro_jump,max_pairs,mb,MC,mc0,mc4,mc5,mc5i,mc5p,mcs,mcub,mcub1,mcud,mcud1,mcuf,mcuf1,mcuu,mcuu1,md,me,meml,memory_above,memory_below,memory_lock,memory_unlock,memu,meta_off,meta_on,mgc,mh,mhpa,mi,Mi,micro_col_size,micro_column_address,micro_down,micro_left,micro_line_size,micro_right,micro_row_address,micro_up,minfo,mir,mjump,mk,ml,ML,mls,mm,mo,mouse_info,move_insert_mode,move_standout_mode,mp,mr,MR,mrcup,ms,msgr,MT,mu,mvpa,MW,nc,NC,ncv,nd,ND,ndscr,needs_xon_xoff,nel,newline,new_line_delay,nl,Nl,NL,nlab,no_color_video,no_correctly_working_cr,no_esc_ctlc,non_dest_scroll_region,non_rev_rmcup,no_pad_char,NP,npc,npins,NR,nrrmc,ns,number_of_function_keys,number_of_pins,num_labels,nw,nx,nxon,oc,op,orc,order_of_pins,orhi,orig_colors,orig_pair,orl,orvi,os,OTbc,OTbs,OTdB,OTdC,OTdN,OTdT,OTG1,OTG2,OTG3,OTG4,OTGC,OTGD,OTGH,OTGL,OTGR,OTGU,OTGV,other_non_function_keys,OTi2,OTkn,OTko,OTma,OTMT,OTnc,OTnl,OTNL,OTns,OTpt,OTrs,OTug,OTxr,output_res_char,output_res_horz_inch,output_res_line,output_res_vert_inch,over_strike,pa,PA,pad,pad_char,padding_baud_rate,pairs,parm_dch,parm_delete_line,parm_down_cursor,parm_down_micro,parm_ich,parm_index,parm_insert_line,parm_left_cursor,parm_left_micro,parm_right_cursor,parm_right_micro,parm_rindex,parm_up_cursor,parm_up_micro,pause,pb,pc,pc_term_options,pctrm,pf,pfkey,pfloc,pfx,pfxl,pk,pkey_key,pkey_local,pkey_plab,pkey_xmit,pl,plab_norm,pln,pn,po,pO,porder,print_rate,print_screen,prot,prtr_non,prtr_off,prtr_on,prtr_silent,ps,pt,PU,pulse,px,QD,qdial,quick_dial,r1,r2,r3,RA,rbim,rc,RC,rcsd,remove_clock,rep,repeat_char,req_for_input,req_mouse_pos,reqmp,reset_1string,reset_2string,reset_3string,reset_file,restore_cursor,return_does_clr_eol,rev,rf,RF,rfi,ri,RI,rin,ritm,rlm,rmacs,rmam,rmclk,rmcup,rmdc,rmicm,rmir,rmkx,rmln,rmm,rmp,rmpch,rmsc,rmso,rmul,rmxon,row_address,row_addr_glitch,rp,rP,RQ,rs,rs1,rs2,rs3,rshm,rsubm,rsupm,rum,rvert,rwidm,RX,s0,s0ds,s1,S1,s1ds,s2,S2,s2ds,s3,S3,s3ds,S4,S5,S6,S7,S8,sa,sA,SA,sam,save_cursor,Sb,sbim,sc,SC,scancode_escape,scesa,scesc,sclk,scp,scroll_forward,scroll_reverse,scs,scsd,sdrfq,se,select_char_set,semi_auto_right_margin,set0_des_seq,set1_des_seq,set2_des_seq,set3_des_seq,set_a_attributes,setab,set_a_background,setaf,set_a_foreground,set_attributes,setb,set_background,set_bottom_margin,set_bottom_margin_parm,set_clock,setcolor,set_color_band,set_color_pair,setf,set_foreground,set_left_margin,set_left_margin_parm,set_lr_margin,set_page_length,set_pglen_inch,set_right_margin,set_right_margin_parm,set_tab,set_tb_margin,set_top_margin,set_top_margin_parm,set_window,sf,Sf,SF,sg,sgr,sgr0,sgr1,sitm,sL,slength,slines,slm,smacs,smam,smcup,smdc,smgb,smgbp,smgl,smglp,smglr,smgr,smgrp,smgt,smgtb,smgtp,smicm,smir,smkx,smln,smm,smpch,smsc,smso,smul,smxon,snlq,snrmq,so,sp,spinh,spinv,sr,SR,sshm,ssubm,ssupm,st,start_bit_image,start_char_set_def,status_line_esc_ok,stop_bit_image,stop_char_set_def,subcs,subscript_characters,sum,supcs,superscript_characters,swidm,SX,ta,tab,tbc,te,termcap_init2,termcap_reset,these_cause_cr,ti,tilde_glitch,TO,tone,topl,to_status_line,transparent_underline,ts,tsl,u0,u1,u2,u3,u4,u5,u6,u7,u8,u9,uc,ue,ug,ul,underline_char,up,UP,up_half_line,us,user0,user1,user2,user3,user4,user5,user6,user7,user8,user9,ut,vb,ve,vi,virtual_terminal,vpa,vs,vt,WA,wait,wait_tone,WG,wi,widcs,wide_char_size,width_status_line,wind,wingo,wnum,ws,wsl,xb,xenl,XF,Xh,xhp,xhpa,xl,Xl,xmc,xn,XN,xo,Xo,xoffc,xoff_character,xon,xonc,xon_character,xon_xoff,xr,Xr,xs,xsb,xt,Xt,Xv,xvpa,Xy,Ya,YA,Yb,YB,Yc,YC,Yd,YD,Ye,YE,Yf,YF,Yg,YG,Yh,Yi,Yj,Yk,Yl,Ym,Yn,Yo,Yp,Yv,Yw,Yx,Yy,Yz,YZ,Za,ZA,Zb,ZB,Zc,ZC,Zd,ZD,Ze,ZE,zerom,zero_motion,Zf,ZF,Zg,ZG,Zh,ZH,Zi,ZI,Zj,ZJ,Zk,ZK,Zl,ZL,Zm,ZM,Zn,ZN,Zo,ZO,Zp,ZP,Zq,ZQ,Zr,ZR,Zs,ZS,Zt,ZT,Zu,ZU,Zv,ZV,Zw,ZW,Zx,ZX,Zy,ZY,Zz,ZZ

TERMINAL TYPE DESCRIPTIONS SOURCE FILE

ANSI, UNIX CONSOLE, AND SPECIAL TYPES
Specials
ANSI.SYS/ISO 6429/ECMA-48 Capabilities
ANSI/ECMA-48 terminals and terminal emulators
DOS ANSI.SYS variants
ANSI console types
BeOS
Linux consoles
Mach
OSF Unix
QNX
NetBSD consoles
FreeBSD console entries
386BSD and BSD/OS Consoles
DEC VT52
DEC VT100 and compatibles
VT100 emulations
X terminal emulators
MGR
UNIX VIRTUAL TERMINALS, VIRTUAL CONSOLES, AND TELNET CLIENTS
Pilot Pro Palm-Top
COMMERCIAL WORKSTATION CONSOLES
Alpha consoles
Sun consoles
Iris consoles
NeWS consoles
NeXT consoles
Sony NEWS workstations
Common Desktop Environment
Non-Unix Consoles
COMMON TERMINAL TYPES
Altos
Hewlett-Packard (hp)
Honeywell-Bull
Lear-Siegler (adm)
Prime
Qume (qvt)
Televideo (tvi)
Visual (vi)
Wyse (wy)
Kermit terminal emulations
NON-ANSI TERMINAL EMULATIONS
Avatar
RBcomm
LCD DISPLAYS
Matrix Orbital
OLDER TERMINAL TYPES
AT&T (att, tty)
Ampex (Dialogue)
Ann Arbor (aa)
Applied Digital Data Systems (adds)
C. Itoh Electronics
Control Data (cdc)
Getronics
Human Designed Systems (Concept)
Contel Business Systems.
Data General (dg)
Datamedia (dm)
Falco

Just something sorta cool for you to check out

{
 local t=`tputm 'clear' 'setaf 75'` l a b f=/tmp/ps IFS=' ';
exec 6<>$f;ps L|tr -s ' ' &>$f;
while read -u6 l;do a=${l/% */} b=${l/* /};
figlet -rtw $((${COLUMNS} /2 )) -f big "$l";
tput sgr0;
command ps wwo pid:6,user:8,vsize:8,comm:20,$a:50 k -$a -A;cont;
done;
};

Terminal Escape Code Zen originally appeared on AskApache.com

This is part of the GRUB article on the Arch Linux wiki that I contributed. As of now, just a copy.

The grub menu.lst provides for a convenient way to add a number of entries with extended kernel parameters to configure all sorts of advanced settings to enable you to quickly and conveniently boot into your existing system with varying levels of debugging output. It's very easy and useful to create several levels of debugging just by adding additional entries to your grub configuration. And if you ever have issues or problems down the road due to a power-failure or hardware failure, it can save you hours of trouble, and of course nothing can beat debugging output when it comes to learning about your system.

Useful Menu.lst Entries

If you are interested in debugging, then you deserve some grub entries for powerusers, here are a few that I like (just add to your menu.lst).

title Shutdown the Computer
halt
 
title Reboot the Computer
reboot
 
title Command Line
commandline
 
title Install GRUB to hd0 MBR
root (hd0,0)
setup (hd0)
 
title Matrix
color green/black light-green/green
 
title Scan for /boot/grub/menu.lst
find --set-root --ignore-floppies /boot/grub/menu.lst
configfile /boot/grub/menu.lst
 
title Scan for /boot/menu.lst
find --set-root --ignore-floppies /menu.lst
configfile /boot/menu.lst
 
# http://www.vortex.prodigynet.co.uk/x86test/
title    Run x86test (CPU Info)
kernel /boot/x86test_zImage.bin
#wget http://www.vortex.prodigynet.co.uk/x86test/x86test_zImage.bin
 
# http://www.memtest.org/
title    Run memtest86+ (Memory Testing)
kernel /boot/memtest86+-1.70.bin

Light Debug

A quick way to see more verbose messages on your console is to bootup your normal grub entry after appending verbose to the kernel line. This simple word added to your kernel line turns on more logging thanks to the /etc/rc.sysinit file, which at the top of the file runs:

if /bin/grep -q " verbose" /proc/cmdline; then /bin/dmesg -n 8; fi

Very simple way to get a bit more messages and debug output in your logs.

title  Arch Linux DEBUG Light
kernel /vmlinuz26 root=/dev/disk/by-label/ROOT ro rootwait verbose
initrd /kernel26.img

Medium Debug

This example menu.lst entry turns on real logging that is set by the kernel and not in an init script. Adding the debug kernel parameter to your kernel line is recognized by a lot of linux internals and enables quite a bit of debugging compared to the default.

title Arch Linux DEBUG Medium
kernel /vmlinuz26 root=/dev/disk/by-label/ROOT ro rootdelay=5 panic=10 debug
initrd /kernel26.img

Heavy Debug

An even more impressive kernel parameter is the ignore_loglevel, which causes the system to ignore any loglevel and keeps the internal loglevel at the maximum debugging level, basically rendering dmesg unable to lower the debug level.

title Arch Linux DEBUG Heavy
kernel /vmlinuz26 root=/dev/disk/by-label/ROOT ro rootdelay=5 panic=10 debug ignore_loglevel
initrd /kernel26.img

Extreme Debug

If the "Heavy Debug" seemed like a lot of output, thats about 1/2 of the logging that occurs with this example. This does a couple things, it uses the earlyprintk parameter to setup your kernel for "early" "printing" of messages to your "vga" screen. The ,keep just lets it stay on the screen longer. This will let you see logs that normally are hidden due to the boot-up process. This also changes the log buffer length to 10MB, and also instructs that any fatal signals be printed with print_fatal_signals. The last one, sched_debug, you can look up in the very excellent kernel documentation on kernel parameters.

title Arch Linux DEBUG Extreme
kernel /vmlinuz26 root=/dev/disk/by-label/ROOT ro debug ignore_loglevel log_buf_len=10M print_fatal_signals=1 LOGLEVEL=8 earlyprintk=vga,keep sched_debug
initrd /kernel26.img

Insane Debug

The first few debugging examples showed some really nice kernel parameters to turn on really verbose debugging. This kind of debugging is absolutely critical if you want to max out your system or just learn more about what is going on behind the scenes. But there is a final trick that is my favorite, it's the ability to set both environment variables, and more importantly, module parameters at boot.

As an example, here is the boot line that I am using at the moment on an older Dell Desktop, just to illustrate module parameters and environment vars.

title  Arch Linux X-256
kernel /vmlinuz26 root=/dev/disk/by-label/ROOT ro rootwait pause_on_oops=5 panic=60 i915.modeset=1 no_console_suspend ipv6.disable=1 TERM=xterm-256color quiet 5
initrd /kernel26.img

Since it's low on both memory and CPU, I disable ipv6. I also turn on kernel modesetting for the i915 video card, set my terminal to be xterm-256color, and boot straight into X. This lets me use a very optimized arch-linux configuration, amazing how fast thanks to using slim as the login manager, ratpoison as my window manager, and terminal with tmux as my login shell, all from boot, as the pstree shows (plus Synergy!).

init,1
  |-slim,3096
  |   |-X,3098 -nolisten tcp vt07 -auth /var/run/slim.auth
  |   `-ratpoison,3107,askapache
  |       |-terminal,5341 -x sh -c exec /usr/bin/tmux -2 -l -u -q attach -d -t tmux-askapache
  |       |   |-bash,11165
  |       |   |-tmux,5345 -2 -l -u -q attach -d -t tmux-askapache
  |       |   `-{terminal},5346
  |       `-xscreensaver,3113 -no-splash
  |-synergyc,6121,galileo -f --name galileo-fire --restart 10.66.66.2:26666
  |
  `-tmux,5348,askapache -2 -l -u -q attach -d -t tmux-askapache
      |-bash,5351
      |   `-ssh,9969 lug@askapache.com
      `-bash,5868
         `-vim,11149 -p sda1/grub/menu.lst /boot/grub/menu.lst

That kind of optimized system is only possible if you first can figure out your system, by debugging both the kernel as previously illustrated, debugging the init process, and most importantly, by debugging the modules enabled for your system's hardware/firmware/software. Debugging modules is challenging but worth the effort, and then you are able to do some truly insane debugging from grub like the following example, note that the actual grub entry is all on one line, but I split it into 4 lines so you could see it all. This basically turns on every module on this little Dell desktop to be at the absolute max debug level. There is so much logging when I boot this that the system grinds to a halt and is slower than a TI-89 calculator (See Improve Boot Performance).

title  Arch Linux DEBUG INSANE
kernel /vmlinuz26 root=/dev/disk/by-label/ROOT ro rootwait ignore_loglevel debug debug_locks_verbose=1 sched_debug initcall_debug mminit_loglevel=4 udev.log_priority=8
       loglevel=8 earlyprintk=vga,keep log_buf_len=10M print_fatal_signals=1 apm.debug=Y i8042.debug=Y drm.debug=1 scsi_logging_level=1 usbserial.debug=Y
       option.debug=Y pl2303.debug=Y firewire_ohci.debug=1 hid.debug=1 pci_hotplug.debug=Y pci_hotplug.debug_acpi=Y shpchp.shpchp_debug=Y apic=debug
       show_lapic=all hpet=verbose lmb=debug pause_on_oops=5 panic=10 sysrq_always_enabled
initrd /kernel26.img

A couple key items from that grub entry are sysrq_always_enabled which forces on the sysrq magic, which really is a lifesaver when debugging at this level as your machine will freeze/stop-responding sometimes and it's nice to use sysrq to kill all tasks, change the loglevel, unmount all filesystems, or do a hard reboot. Another key parameter is the initcall_debug, which debugs the init process in excruciating detail. Very useful at times. The last parametery I find very useful is the udev.log_priority=8 to turn on udev logging.

Break Into Init

For instance, If you add break=y to your kernel cmdline, init will pause early in the boot process (after loading modules) and launch an interactive sh shell which can be used for troubleshooting purposes. (Normal boot continues after logout.) This is very similar to the shell that shows up if your computer gets turned off before it is able to shutdown properly. But using this parameter lets you enter into this mode differently at will.

title  Arch Linux Init Break
kernel /vmlinuz26 root=/dev/disk/by-label/ROOT ro rootwait break=y
initrd /kernel26.img

Debugging init

This awesome parameter udev.log_priority=8 does the same thing as editing the file /etc/udev/udev.conf except it executes earlier, turning on debugging output for udev. If you want to know your hardware, that is the key parameter right there. Another trick is if you change the /etc/udev/udev.conf to be verbose, then you can make your initrd image include that file to turn on verbose udeb debugging by adding it to your {{Filename|/etc/mkinitcpio.conf} like:

FILES="/etc/modprobe.d/modprobe.conf /etc/udev/udev.conf"

, which on arch is as easy as

# mkinitcpio -p kernel26

Debugging udev is key because the initrd performs a root change at the end of its run to usually launch a program like /sbin/init as part of a chroot, and unless the new file system has a valid /dev directory, udev must be initialized before invoking chroot in order to provide /dev/console.

exec chroot . /sbin/init <dev/console >dev/console 2>&1

So basically, you aren't able to view the logs that are generated before /dev/console is initialized by udev or by a special initrd you compiled yourself. One method the kernel developers use to be able to still get the log messages generated before /dev/console is available is to provide an alternative console that you can enable or disable from grub.

Net Console

If you read through the kernel documentation regarding debugging, you will hear about Netconsole, which can be loaded from the kernel line in GRUB, compiled into your kernel, or loaded at runtime as a module. Having a netconsole entry in your menu.lst is most excellent for debugging slower computers like old laptops or thin-clients. It's easy to use. Just setup a 2nd computer (running arch) to accept syslog requests on a remote port, very fast and quick to do on arch-linux, 1 line to syslog.conf. Then you could use a log-color-parser like ccze to view all syslog logs, or just tail your everything.log. Then on your laptop, boot up and select the netconsole entry from the grub menu, and you will start seeing as much logging as you want on your syslog system. This logging lets you view even earlier log output than is available with the earlyprintk=vga kernel parameter, as netconsole is used by kernel hackers and developers, so it's very powerful.

title  Arch Linux DEBUG Netconsole
kernel /vmlinuz26 root=/dev/disk/by-label/ROOT ro netconsole=514@10.0.0.2/12:34:56:78:9a:bc debug ignore_loglevel
initrd /kernel26.img

Hijacking cmdline

If you do not have access to GRUB or the kernel boottime cmdline, like on a server or virtual machine, as long as you have root permissions you can still enable this kind of simplistic verbose logging using a neat hack. While you cannot modify the /proc/cmdline even as root, you can place your own cmdline file on top of /proc/cmdline, so that accessing /proc/cmdline actually accesses your file.

For example if I cat /proc/cmdline, I have the following:

root=/dev/disk/by-label/ROOT ro console=tty1 logo.nologo quiet

So I use a simple sed command to replace quiet with verbose like:

sed 's/ quiet/ verbose/' /proc/cmdline > /root/cmdline

Then I bind mount /root/cmdline so that it becomes /proc/cmdline, using the -n option to mount so that this mount won't be recorded in the systems mtab.

mount -n --bind -o ro /root/cmdline /proc/cmdline

Now if I cat /proc/cmdline, I have the following:

root=/dev/disk/by-label/ROOT ro console=tty1 logo.nologo verbose

Advanced Linux Debugging using a Bootloader (GRUB) originally appeared on AskApache.com

I was trying to find an official, authoritative list of HTTP Status Codes but I kept finding lists that weren't authoritative or complete. So I searched and found my answer in the Apache HTTP Server source code. Once I had the exact HTTP Status Codes and resulting Error Documents sent by Apache, I researched deeper into HTTP Status Codes by reading as many related RFC's as I could find, and several other software source codes were explored. This is the most authoritative list I know of, if you can do better leave a comment and I'll update it. Another thing to keep in mind, the Status code number itself is what is used by software and hardware to make determinations, the phrase returned by the status code is for the human only and does not have any weight other than informing the user.. So "503 Service Unavailable", "503 Service Temporarily Unavailable", and "503 Get the heck outta here" are all completely valid.

Update March 9, 2009: A lot of sites on the web have updated their HTTP status code lists to include the HTTP Status codes listed on this page, including Wikipedia, IANA, W3C, and others, so rest assured this info is accurate and complete. If you'd like to see how to create custom error pages for all of these errors like mine /show-error-506 , then check out this detailed tutorial I just posted.

Contents

• List of All 57 HTTP Response Status Code
• Quick Start to triggering ErrorDocuments for each Status Code
• Automate the ErrorDocument Triggering
  • The htaccess Code
  • PHP script that gets and outputs the Headers/Content
• Headers and Content Returned
• Apache Source Code
  • httpd.h
  • http_protocol.c

57 APACHE HTTP STATUS RESPONSE CODES

Once I compiled the list of Apache recognized HTTP Status Codes, I was dying to see them all in action (i.e. the corresponding ErrorDocument). At first I thought I would have to create a php or perl script emulating each of the 57 HTTP Status Codes, a tedious undertaking I wasn't about to do. Instead I "asked Apache" by searching the Apache HTTP Documentation for ambiguity sending Status Codes and/or triggering ErrorDocuments with an Apache Directive.
While reading up on mod_alias and the Redirect directive I found:

Apache Docs

Syntax: Redirect [status] URL-path URL The status argument can be used to return other HTTP status codes. Other status codes can be returned by giving the numeric status code as the value of status. If the status is between 300 and 399, the URL argument must be present, otherwise it must be omitted.

100 Continue

ErrorDocument Continue | Sample 100 Continue
This means that the server has received the request headers, and that the client should proceed to send the request body (in case of a request which needs to be sent; for example, a POST request). If the request body is large, sending it to a server when a request has already been rejected based upon inappropriate headers is inefficient. To have a server check if the request could be accepted based on the requests headers alone, a client must send Expect: 100-continue as a header in its initial request (see RFC 2616 14.20 Expect header) and check if a 100 Continue status code is received in response before continuing (or receive 417 Expectation Failed and not continue).

101 Switching Protocols

ErrorDocument Switching Protocols | Sample 101 Switching Protocols
This means the requester has asked the server to switch protocols and the server is acknowledging that it will do so.[3]

102 Processing

ErrorDocument Processing | Sample 102 Processing
(WebDAV) - (RFC 2518 )

200 OK

ErrorDocument OK | Sample 200 OK
Standard response for successful HTTP requests. The actual response will depend on the request method used. In a GET request, the response will contain an entity corresponding to the requested resource. In a POST request the response will contain an entity describing or containing the result of the action.

201 Created

ErrorDocument Created | Sample 201 Created
The request has been fulfilled and resulted in a new resource being created.

202 Accepted

ErrorDocument Accepted | Sample 202 Accepted
The request has been accepted for processing, but the processing has not been completed. The request might or might not eventually be acted upon, as it might be disallowed when processing actually takes place.

203 Non-Authoritative Information

ErrorDocument Non-Authoritative Information | Sample 203 Non-Authoritative Information
The server successfully processed the request, but is returning information that may be from another source.

204 No Content

ErrorDocument No Content | Sample 204 No Content
The server successfully processed the request, but is not returning any content.

205 Reset Content

ErrorDocument Reset Content | Sample 205 Reset Content
The server successfully processed the request, but is not returning any content. Unlike a 204 response, this response requires that the requester reset the document view.

206 Partial Content

ErrorDocument Partial Content | Sample 206 Partial Content
The server is delivering only part of the resource due to a range header sent by the client. This is used by tools like wget to enable resuming of interrupted downloads, or split a download into multiple simultaneous streams.

207 Multi-Status

ErrorDocument Multi-Status | Sample 207 Multi-Status
(WebDAV) - The message body that follows is an XML message and can contain a number of separate response codes, depending on how many sub-requests were made.

226 IM Used

ErrorDocument IM Used | Sample 226 IM Used
The server has fulfilled a GET request for the resource, and the response is a representation of the result of one or more instance-manipulations applied to the current instance. The actual current instance might not be available except by combining this response with other previous or future responses, as appropriate for the specific instance-manipulation(s).

300 Multiple Choices

ErrorDocument Multiple Choices | Sample 300 Multiple Choices
Indicates multiple options for the resource that the client may follow. It, for instance, could be used to present different format options for video, list files with different extensions, or word sense disambiguation.

301 Moved Permanently

ErrorDocument Moved Permanently | Sample 301 Moved Permanently
This and all future requests should be directed to the given URI.

302 Found

ErrorDocument Found | Sample 302 Found
This is the most popular redirect code[citation needed], but also an example of industrial practice contradicting the standard. HTTP/1.0 specification (RFC 1945 ) required the client to perform a temporary redirect (the original describing phrase was "Moved Temporarily"), but popular browsers implemented it as a 303 See Other. Therefore, HTTP/1.1 added status codes 303 and 307 to disambiguate between the two behaviours. However, the majority of Web applications and frameworks still use the 302 status code as if it were the 303.

303 See Other

ErrorDocument See Other | Sample 303 See Other
The response to the request can be found under another URI using a GET method. When received in response to a PUT, it should be assumed that the server has received the data and the redirect should be issued with a separate GET message.

304 Not Modified

ErrorDocument Not Modified | Sample 304 Not Modified
Indicates the resource has not been modified since last requested. Typically, the HTTP client provides a header like the If-Modified-Since header to provide a time against which to compare. Utilizing this saves bandwidth and reprocessing on both the server and client, as only the header data must be sent and received in comparison to the entirety of the page being re-processed by the server, then resent using more bandwidth of the server and client.

305 Use Proxy

ErrorDocument Use Proxy | Sample 305 Use Proxy
Many HTTP clients (such as Mozilla[4] and Internet Explorer) do not correctly handle responses with this status code, primarily for security reasons.

306 Switch Proxy

ErrorDocument Switch Proxy | Sample 306 Switch Proxy
No longer used.

307 Temporary Redirect

ErrorDocument Temporary Redirect | Sample 307 Temporary Redirect
In this occasion, the request should be repeated with another URI, but future requests can still use the original URI. In contrast to 303, the request method should not be changed when reissuing the original request. For instance, a POST request must be repeated using another POST request.

400 Bad Request

ErrorDocument Bad Request | Sample 400 Bad Request
The request contains bad syntax or cannot be fulfilled.

401 Unauthorized

ErrorDocument Unauthorized | Sample 401 Unauthorized
Similar to 403 Forbidden, but specifically for use when authentication is possible but has failed or not yet been provided. The response must include a WWW-Authenticate header field containing a challenge applicable to the requested resource. See Basic access authentication and Digest access authentication.

402 Payment Required

ErrorDocument Payment Required | Sample 402 Payment Required
The original intention was that this code might be used as part of some form of digital cash or micropayment scheme, but that has not happened, and this code has never been used.

403 Forbidden

ErrorDocument Forbidden | Sample 403 Forbidden
The request was a legal request, but the server is refusing to respond to it. Unlike a 401 Unauthorized response, authenticating will make no difference.

404 Not Found

ErrorDocument Not Found | Sample 404 Not Found
The requested resource could not be found but may be available again in the future. Subsequent requests by the client are permissible.

405 Method Not Allowed

ErrorDocument Method Not Allowed | Sample 405 Method Not Allowed
A request was made of a resource using a request method not supported by that resource; for example, using GET on a form which requires data to be presented via POST, or using PUT on a read-only resource.

406 Not Acceptable

ErrorDocument Not Acceptable | Sample 406 Not Acceptable
The requested resource is only capable of generating content not acceptable according to the Accept headers sent in the request.

407 Proxy Authentication Required

ErrorDocument Proxy Authentication Required | Sample 407 Proxy Authentication Required
Required

408 Request Timeout

ErrorDocument Request Timeout | Sample 408 Request Timeout
The server timed out waiting for the request.

409 Conflict

ErrorDocument Conflict | Sample 409 Conflict
Indicates that the request could not be processed because of conflict in the request, such as an edit conflict.

410 Gone

ErrorDocument Gone | Sample 410 Gone
Indicates that the resource requested is no longer available and will not be available again. This should be used when a resource has been intentionally removed; however, it is not necessary to return this code and a 404 Not Found can be issued instead. Upon receiving a 410 status code, the client should not request the resource again in the future. Clients such as search engines should remove the resource from their indexes.

411 Length Required

ErrorDocument Length Required | Sample 411 Length Required
The request did not specify the length of its content, which is required by the requested resource.

412 Precondition Failed

ErrorDocument Precondition Failed | Sample 412 Precondition Failed
The server does not meet one of the preconditions that the requester put on the request.

413 Request Entity Too Large

ErrorDocument Request Entity Too Large | Sample 413 Request Entity Too Large
The request is larger than the server is willing or able to process.

414 Request-URI Too Long

ErrorDocument Request-URI Too Long | Sample 414 Request-URI Too Long
The URI provided was too long for the server to process.

415 Unsupported Media Type

ErrorDocument Unsupported Media Type | Sample 415 Unsupported Media Type
The request did not specify any media types that the server or resource supports. For example the client specified that an image resource should be served as image/svg+xml, but the server cannot find a matching version of the image.

416 Requested Range Not Satisfiable

ErrorDocument Requested Range Not Satisfiable | Sample 416 Requested Range Not Satisfiable
The client has asked for a portion of the file, but the server cannot supply that portion (for example, if the client asked for a part of the file that lies beyond the end of the file).

417 Expectation Failed

ErrorDocument Expectation Failed | Sample 417 Expectation Failed
The server cannot meet the requirements of the Expect request-header field.

418 I'm a teapot

ErrorDocument I'm a teapot | Sample 418 I'm a teapot
The HTCPCP server is a teapot. The responding entity MAY be short and stout. Defined by the April Fools specification RFC 2324. See Hyper Text Coffee Pot Control Protocol for more information.

422 Unprocessable Entity

ErrorDocument Unprocessable Entity | Sample 422 Unprocessable Entity
(WebDAV) (RFC 4918 ) - The request was well-formed but was unable to be followed due to semantic errors.

423 Locked

ErrorDocument Locked | Sample 423 Locked
(WebDAV) (RFC 4918 ) - The resource that is being accessed is locked

424 Failed Dependency

ErrorDocument Failed Dependency | Sample 424 Failed Dependency
(WebDAV) (RFC 4918 ) - The request failed due to failure of a previous request (e.g. a PROPPATCH).

425 Unordered Collection

ErrorDocument Unordered Collection | Sample 425 Unordered Collection
Defined in drafts of WebDav Advanced Collections, but not present in "Web Distributed Authoring and Versioning (WebDAV) Ordered Collections Protocol" (RFC 3648).

426 Upgrade Required

ErrorDocument Upgrade Required | Sample 426 Upgrade Required
(RFC 2817 ) - The client should switch to TLS/1.0.

449 Retry With

ErrorDocument Retry With | Sample 449 Retry With
A Microsoft extension. The request should be retried after doing the appropriate action.

500 Internal Server Error

ErrorDocument Internal Server Error | Sample 500 Internal Server Error
A generic error message, given when no more specific message is suitable.

501 Not Implemented

ErrorDocument Not Implemented | Sample 501 Not Implemented
The server either does not recognise the request method, or it lacks the ability to fulfil the request.

502 Bad Gateway

ErrorDocument Bad Gateway | Sample 502 Bad Gateway
The server was acting as a gateway or proxy and received an invalid response from the upstream server.

503 Service Unavailable

ErrorDocument Service Unavailable | Sample 503 Service Unavailable
The server is currently unavailable (because it is overloaded or down for maintenance). Generally, this is a temporary state.

504 Gateway Timeout

ErrorDocument Gateway Timeout | Sample 504 Gateway Timeout
The server was acting as a gateway or proxy and did not receive a timely request from the upstream server.

505 HTTP Version Not Supported

ErrorDocument HTTP Version Not Supported | Sample 505 HTTP Version Not Supported
The server does not support the HTTP protocol version used in the request.

506 Variant Also Negotiates

ErrorDocument Variant Also Negotiates | Sample 506 Variant Also Negotiates
(RFC 2295 ) - Transparent content negotiation for the request, results in a circular reference.

507 Insufficient Storage

ErrorDocument Insufficient Storage | Sample 507 Insufficient Storage
(WebDAV) (RFC 4918 )

509 Bandwidth Limit Exceeded

ErrorDocument Bandwidth Limit Exceeded | Sample 509 Bandwidth Limit Exceeded
(Apache bw/limited extension) - This status code, while used by many servers, is not specified in any RFCs.

510 Not Extended

ErrorDocument Not Extended | Sample 510 Not Extended
(RFC 2774 ) - Further extensions to the request are required for the server to fulfil it.

1xx Info / Informational

HTTP_INFO - Request received, continuing process. Indicates a provisional response, consisting only of the Status-Line and optional headers, and is terminated by an empty line.

• 100 Continue - HTTP_CONTINUE
• 101 Switching Protocols - HTTP_SWITCHING_PROTOCOLS
• 102 Processing - HTTP_PROCESSING

2xx Success / OK

HTTP_SUCCESS - The action was successfully received, understood, and accepted. Indicates that the client's request was successfully received, understood, and accepted.

• 200 OK - HTTP_OK
• 201 Created - HTTP_CREATED
• 202 Accepted - HTTP_ACCEPTED
• 203 Non-Authoritative Information - HTTP_NON_AUTHORITATIVE
• 204 No Content - HTTP_NO_CONTENT
• 205 Reset Content - HTTP_RESET_CONTENT
• 206 Partial Content - HTTP_PARTIAL_CONTENT
• 207 Multi-Status - HTTP_MULTI_STATUS

3xx Redirect

HTTP_REDIRECT - The client must take additional action to complete the request. Indicates that further action needs to be taken by the user-agent in order to fulfill the request. The action required may be carried out by the user agent without interaction with the user if and only if the method used in the second request is GET or HEAD. A user agent should not automatically redirect a request more than 5 times, since such redirections usually indicate an infinite loop.

• 300 Multiple Choices - HTTP_MULTIPLE_CHOICES
• 301 Moved Permanently - HTTP_MOVED_PERMANENTLY
• 302 Found - HTTP_MOVED_TEMPORARILY
• 303 See Other - HTTP_SEE_OTHER
• 304 Not Modified - HTTP_NOT_MODIFIED
• 305 Use Proxy - HTTP_USE_PROXY
• 306 unused - UNUSED
• 307 Temporary Redirect - HTTP_TEMPORARY_REDIRECT

4xx Client Error

HTTP_CLIENT_ERROR - The request contains bad syntax or cannot be fulfilled. Indicates case where client seems to have erred. Except when responding to a HEAD request, the server should include an entity containing an explanation of the error situation, and whether it is a temporary or permanent condition.

• 400 Bad Request - HTTP_BAD_REQUEST
• 401 Authorization Required - HTTP_UNAUTHORIZED
• 402 Payment Required - HTTP_PAYMENT_REQUIRED
• 403 Forbidden - HTTP_FORBIDDEN
• 404 Not Found - HTTP_NOT_FOUND
• 405 Method Not Allowed - HTTP_METHOD_NOT_ALLOWED
• 406 Not Acceptable - HTTP_NOT_ACCEPTABLE
• 407 Proxy Authentication Required - HTTP_PROXY_AUTHENTICATION_REQUIRED
• 408 Request Time-out - HTTP_REQUEST_TIME_OUT
• 409 Conflict - HTTP_CONFLICT
• 410 Gone - HTTP_GONE
• 411 Length Required - HTTP_LENGTH_REQUIRED
• 412 Precondition Failed - HTTP_PRECONDITION_FAILED
• 413 Request Entity Too Large - HTTP_REQUEST_ENTITY_TOO_LARGE
• 414 Request-URI Too Large - HTTP_REQUEST_URI_TOO_LARGE
• 415 Unsupported Media Type - HTTP_UNSUPPORTED_MEDIA_TYPE
• 416 Requested Range Not Satisfiable - HTTP_RANGE_NOT_SATISFIABLE
• 417 Expectation Failed - HTTP_EXPECTATION_FAILED
• 418 I'm a teapot - UNUSED
• 419 unused - UNUSED
• 420 unused - UNUSED
• 421 unused - UNUSED
• 422 Unprocessable Entity - HTTP_UNPROCESSABLE_ENTITY
• 423 Locked - HTTP_LOCKED
• 424 Failed Dependency - HTTP_FAILED_DEPENDENCY
• 425 No code - HTTP_NO_CODE
• 426 Upgrade Required - HTTP_UPGRADE_REQUIRED

5xx Server Error

HTTP_SERVER_ERROR - The server failed to fulfill an apparently valid request. Indicate cases in which the server is aware that it has erred or is incapable of performing the request. Except when responding to a HEAD request, the server should include an entity containing an explanation of the error situation, and whether it is a temporary or permanent condition. User agents should display any included entity to the user. These response codes are applicable to any request method.

• 500 Internal Server Error - HTTP_INTERNAL_SERVER_ERROR
• 501 Method Not Implemented - HTTP_NOT_IMPLEMENTED
• 502 Bad Gateway - HTTP_BAD_GATEWAY
• 503 Service Temporarily Unavailable - HTTP_SERVICE_UNAVAILABLE
• 504 Gateway Time-out - HTTP_GATEWAY_TIME_OUT
• 505 HTTP Version Not Supported - HTTP_VERSION_NOT_SUPPORTED
• 506 Variant Also Negotiates - HTTP_VARIANT_ALSO_VARIES
• 507 Insufficient Storage - HTTP_INSUFFICIENT_STORAGE
• 508 unused - UNUSED
• 509 unused - UNUSED
• 510 Not Extended - HTTP_NOT_EXTENDED

Quick Start to triggering ErrorDocuments for each Status Code

Let start with a quick and easy example. Add the following Redirect rules to your htaccess file, then open your browser and goto each url like yoursite.com/e/400. Don't create an /e/ directory or any files.

Redirect 400 /e/400
Redirect 503 /e/503
Redirect 405 /e/405

Automate the ErrorDocument Triggering

The htaccess Redirects

When a Status code is encountered, Apache outputs the Header and the ErrorDocument for that error code. So you can view any Header and the default ErrorDocument, by causing that numerical error code, which is caused by the Status Code.

For instance, if you request a file that doesn't exist, a 404 Not Found Header is issued and the corresponding ErrorDocument is served with the 404 Not Found Header.

Redirect 100 /e/100
Redirect 101 /e/101
Redirect 102 /e/102
Redirect 200 /e/200
Redirect 201 /e/201
Redirect 202 /e/202
Redirect 203 /e/203
Redirect 204 /e/204
Redirect 205 /e/205
Redirect 206 /e/206
Redirect 207 /e/207
Redirect 300 /e/300 http://www.askapache.com/?s=300
Redirect 301 /e/301 http://www.askapache.com/?s=301
Redirect 302 /e/302 http://www.askapache.com/?s=302
Redirect 303 /e/303 http://www.askapache.com/?s=303
Redirect 304 /e/304 http://www.askapache.com/?s=304
Redirect 305 /e/305 http://www.askapache.com/?s=305
Redirect 306 /e/306 http://www.askapache.com/?s=306
Redirect 307 /e/307 http://www.askapache.com/?s=307
Redirect 400 /e/400
Redirect 401 /e/401
Redirect 402 /e/402
Redirect 403 /e/403
Redirect 404 /e/404
Redirect 405 /e/405
Redirect 406 /e/406
Redirect 407 /e/407
Redirect 408 /e/408
Redirect 409 /e/409
Redirect 410 /e/410
Redirect 411 /e/411
Redirect 412 /e/412
Redirect 413 /e/413
Redirect 414 /e/414
Redirect 415 /e/415
Redirect 416 /e/416
Redirect 417 /e/417
Redirect 418 /e/418
Redirect 419 /e/419
Redirect 420 /e/420
Redirect 421 /e/421
Redirect 422 /e/422
Redirect 423 /e/423
Redirect 424 /e/424
Redirect 425 /e/425
Redirect 426 /e/426
Redirect 500 /e/500
Redirect 501 /e/501
Redirect 502 /e/502
Redirect 503 /e/503
Redirect 504 /e/504
Redirect 505 /e/505
Redirect 506 /e/506
Redirect 507 /e/507
Redirect 508 /e/508
Redirect 509 /e/509
Redirect 510 /e/510

PHP script that gets and outputs the Headers/Content

Now all I have to do is add 57 Redirect Directives to my htaccess, and then request each of them 1 at a time from my browser to see the result, and use a packet sniffing program like WireShark to see the Headers. Uh, scratch that, that would take way too long!

Instead I hacked up a simple php script using cURL to automate sending GET Requests to each of the 57 Redirect URL-paths. A side benefit of using the php script is that it performs all 57 Requests concurrently and saves each Requests returned headers and content to an output buffer. After all 57 have been queried, the output buffer is flushed to the browser.

<?php
$SITENAME='http://www.askapache.com';
 
$CODES = array(array('100','101','102'),
array('200','201','202','203','204','205','206','207'),
array('300','301','302','303','304','305','306','307'),
array('400','401','402','403','404','405','406','407','408','409','410','411','412','413',
'414','415','416','417','418','419','420','421','422','423','424','425','426'),
array('500','501','502','503','504','505','506','507','508','509','510'));
 
$TMPSAVETO='/tmp/'.time().'.txt';
 
# if file exists then delete it
if(is_file($TMPSAVETO))unlink($TMPSAVETO);
 
foreach($CODES as $keyd => $res)
{
foreach($res as $key)
{
$ch = curl_init("$SITENAME/e/$key");
$fp = fopen ($TMPSAVETO, "a");
curl_setopt ($ch, CURLOPT_FILE, $fp);
curl_setopt ($ch, CURLOPT_FOLLOWLOCATION ,1);
curl_setopt ($ch, CURLOPT_HEADER ,1);
curl_exec ($ch);
curl_close ($ch);
fclose ($fp);
}
}
$OUT='';
ob_start();
header ("Content-Type: text/plain;");
readfile($TMPSAVETO);
$OUT=ob_get_clean();
echo $OUT;
unlink($TMPSAVETO);
exit;
?>

Headers and Content Returned

100 Continue

HTTP/1.1 100 Continue
<html>
<head>
<title>100 Continue</title>
</head>
<body>
<h1>Continue</h1>
<p>The server encountered an internal error or misconfigurationand was unable to complete your request.</p>
<p>Please contact the server administrator, a@s.com and inform them of the time the error occurred, and anything you might have done that may have caused the error.</p>
<p>More information about this error may be available in the server error log.</p>
</body>
</html>

101 Switching Protocols

HTTP/1.1 101 Switching Protocols<html>
<head>
<title>101 Switching Protocols</title>
</head>
<body>
<h1>Switching Protocols</h1>
<p>The server encountered an internal error or misconfigurationand was unable to complete your request.</p>
<p>Please contact the server administrator, a@s.com and inform them of the time the error occurred, and anything you might have done that may have caused the error.</p>
<p>More information about this error may be available in the server error log.</p>
</body>
</html>

102 Processing

HTTP/1.1 102 Processing
X-Pad: avoid browser bug<html>
<head>
<title>102 Processing</title>
</head>
<body>
<h1>Processing</h1>
<p>The server encountered an internal error or misconfigurationand was unable to complete your request.</p>
<p>Please contact the server administrator, a@s.com and inform them of the time the error occurred, and anything you might have done that may have caused the error.</p>
<p>More information about this error may be available in the server error log.</p>
</body>
</html>

200 OK

HTTP/1.1 200 OK
<html>
<head>
<title>200 OK</title>
</head>
<body>
<h1>OK</h1>
<p>The server encountered an internal error or misconfigurationand was unable to complete your request.</p>
<p>Please contact the server administrator, a@s.com and inform them of the time the error occurred, and anything you might have done that may have caused the error.</p>
<p>More information about this error may be available in the server error log.</p>
</body>
</html>

201 Created

HTTP/1.1 201 Created
<html>
<head>
<title>201 Created</title>
</head>
<body>
<h1>Created</h1>
<p>The server encountered an internal error or misconfigurationand was unable to complete your request.</p>
<p>Please contact the server administrator, a@s.com and inform them of the time the error occurred, and anything you might have done that may have caused the error.</p>
<p>More information about this error may be available in the server error log.</p>
</body>
</html>

202 Accepted

HTTP/1.1 202 Accepted
<html>
<head>
<title>202 Accepted</title>
</head>
<body>
<h1>Accepted</h1>
<p>The server encountered an internal error or misconfigurationand was unable to complete your request.</p>
<p>Please contact the server administrator, a@s.com and inform them of the time the error occurred, and anything you might have done that may have caused the error.</p>
<p>More information about this error may be available in the server error log.</p>
</body>
</html>

203 Non-Authoritative Information

HTTP/1.1 203 Non-Authoritative Information
<html>
<head>
<title>203 Non-Authoritative Information</title>
</head>
<body>
<h1>Non-Authoritative Information</h1>
<p>The server encountered an internal error or misconfigurationand was unable to complete your request.</p>
<p>Please contact the server administrator, a@s.com and inform them of the time the error occurred, and anything you might have done that may have caused the error.</p>
<p>More information about this error may be available in the server error log.</p>
</body>
</html>

204 No Content

HTTP/1.1 204 No Content
Content-Type: text/plain; charset=UTF-8

205 Reset Content

HTTP/1.1 205 Reset Content<html>
<head>
<title>205 Reset Content</title>
</head>
<body>
<h1>Reset Content</h1>
<p>The server encountered an internal error or misconfigurationand was unable to complete your request.</p>
<p>Please contact the server administrator, a@s.com and inform them of the time the error occurred, and anything you might have done that may have caused the error.</p>
<p>More information about this error may be available in the server error log.</p>
</body>
</html>

206 Partial Content

HTTP/1.1 206 Partial Content<html>
<head>
<title>206 Partial Content</title>
</head>
<body>
<h1>Partial Content</h1>
<p>The server encountered an internal error or misconfigurationand was unable to complete your request.</p>
<p>Please contact the server administrator, a@s.com and inform them of the time the error occurred, and anything you might have done that may have caused the error.</p>
<p>More information about this error may be available in the server error log.</p>
</body>
</html>

207 Multi-Status

HTTP/1.1 207 Multi-Status
X-Pad: avoid browser bug<html>
<head>
<title>207 Multi-Status</title>
</head>
<body>
<h1>Multi-Status</h1>
<p>The server encountered an internal error or misconfigurationand was unable to complete your request.</p>
<p>Please contact the server administrator, a@s.com and inform them of the time the error occurred, and anything you might have done that may have caused the error.</p>
<p>More information about this error may be available in the server error log.</p>
</body>
</html>

300 Multiple Choices

HTTP/1.1 300 Multiple Choices
Location: http://www.askapache.com/?s=300<html>
<head>
<title>300 Multiple Choices</title>
</head>
<body>
<h1>Multiple Choices</h1>
</body>
</html>

301 Moved Permanently

HTTP/1.1 301 Moved Permanently
Location: http://www.askapache.com/?s=301<html>
<head>
<title>301 Moved Permanently</title>
</head>
<body>
<h1>Moved Permanently</h1>
<p>The document has moved  <a href="http://www.askapache.com/?s=301">here</a> .</p>
</body>
</html>

302 Found

HTTP/1.1 302 Found
Location: http://www.askapache.com/?s=302<html>
<head>
<title>302 Found</title>
</head>
<body>
<h1>Found</h1>
<p>The document has moved  <a href="http://www.askapache.com/?s=302">here</a> .</p>
</body>
</html>

303 See Other

HTTP/1.1 303 See Other
Location: http://www.askapache.com/?s=303<html>
<head>
<title>303 See Other</title>
</head>
<body>
<h1>See Other</h1>
<p>The answer to your request is located  <a href="http://www.askapache.com/?s=303">here</a> .</p>
</body>
</html>

304 Not Modified

HTTP/1.1 304 Not Modified

305 Use Proxy

HTTP/1.1 305 Use Proxy
Location: http://www.askapache.com/?s=305<html>
<head>
<title>305 Use Proxy</title>
</head>
<body>
<h1>Use Proxy</h1>
<p>This resource is only accessible through the proxy
    http://www.askapache.com/?s=305<br />You will need to configure your client to use that proxy.</p>
</body>
</html>

306 unused

HTTP/1.1 306 unused
Location: http://www.askapache.com/?s=306<html>
<head>
<title>306 unused</title>
</head>
<body>
<h1>unused</h1>
<p>The server encountered an internal error or misconfigurationand was unable to complete your request.</p>
<p>Please contact the server administrator, a@s.com and inform them of the time the error occurred, and anything you might have done that may have caused the error.</p>
<p>More information about this error may be available in the server error log.</p>
</body>
</html>

307 Temporary Redirect

HTTP/1.1 307 Temporary Redirect
Location: http://www.askapache.com/?s=307<html>
<head>
<title>307 Temporary Redirect</title>
</head>
<body>
<h1>Temporary Redirect</h1>
<p>The document has moved  <a href="http://www.askapache.com/?s=307">here</a> .</p>
</body>
</html>

400 Bad Request

HTTP/1.1 400 Bad Request
Connection: close<html>
<head>
<title>400 Bad Request</title>
</head>
<body>
<h1>Bad Request</h1>
<p>Your browser sent a request that this server could not understand.</p>
</body>
</html>

401 Authorization Required

HTTP/1.1 401 Authorization Required<html>
<head>
<title>401 Authorization Required</title>
</head>
<body>
<h1>Authorization Required</h1>
<p>This server could not verify that you
    are authorized to access the document
    requested.  Either you supplied the wrong
    credentials (e.g., bad password), or your
    browser doesn't understand how to supply
    the credentials required.</p>
<p>Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.</p>
</body>
</html>

402 Payment Required

HTTP/1.1 402 Payment Required<html>
<head>
<title>402 Payment Required</title>
</head>
<body>
<h1>Payment Required</h1>
<p>The server encountered an internal error or misconfigurationand was unable to complete your request.</p>
<p>Please contact the server administrator, a@s.com and inform them of the time the error occurred, and anything you might have done that may have caused the error.</p>
<p>More information about this error may be available in the server error log.</p>
</body>
</html>

403 Forbidden

HTTP/1.1 403 Forbidden<html>
<head>
<title>403 Forbidden</title>
</head>
<body>
<h1>Forbidden</h1>
<p>You don't have permission to access /e/403
    on this server.</p>
<p>Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.</p>
</body>
</html>

404 Not Found

HTTP/1.1 404 Not Found<html>
<head>
<title>404 Not Found</title>
</head>
<body>
<h1>Not Found</h1>
<p>The requested URL /e/404 was not found on this server.</p>
</body>
</html>

NOTE:
You will most definately want to check out and use the Google 404 Error Page if you run WordPress.

405 Method Not Allowed

HTTP/1.1 405 Method Not Allowed
Allow: TRACE
<html>
<head>
<title>405 Method Not Allowed</title>
</head>
<body>
<h1>Method Not Allowed</h1>
<p>The requested method GET is not allowed for the URL /e/405.</p>
</body>
</html>

406 Not Acceptable

HTTP/1.1 406 Not Acceptable
<html>
<head>
<title>406 Not Acceptable</title>
</head>
<body>
<h1>Not Acceptable</h1>
<p>An appropriate representation of the requested resource /e/406 could not be found on this server.</p>
</body>
</html>

407 Proxy Authentication Required

HTTP/1.1 407 Proxy Authentication Required<html>
<head>
<title>407 Proxy Authentication Required</title>
</head>
<body>
<h1>Proxy Authentication Required</h1>
<p>This server could not verify that you
    are authorized to access the document
    requested.  Either you supplied the wrong
    credentials (e.g., bad password), or your
    browser doesn't understand how to supply
    the credentials required.</p>
</body>
</html>

408 Request Time-out

HTTP/1.1 408 Request Time-out
Connection: close
<html>
<head>
<title>408 Request Time-out</title>
</head>
<body>
<h1>Request Time-out</h1>
<p>Server timeout waiting for the HTTP request from the client.</p>
</body>
</html>

409 Conflict

HTTP/1.1 409 Conflict
<html>
<head>
<title>409 Conflict</title>
</head>
<body>
<h1>Conflict</h1>
<p>The server encountered an internal error or misconfigurationand was unable to complete your request.</p>
<p>Please contact the server administrator, a@s.com and inform them of the time the error occurred, and anything you might have done that may have caused the error.</p>
<p>More information about this error may be available in the server error log.</p>
</body>
</html>

410 Gone

HTTP/1.1 410 Gone
<html>
<head>
<title>410 Gone</title>
</head>
<body>
<h1>Gone</h1>
<p>The requested resource<br />/e/410<br />is no longer available on this server and there is no forwarding address.
    Please remove all references to this resource.</p>
</body>
</html>

411 Length Required

HTTP/1.1 411 Length Required
Connection: close
<html>
<head>
<title>411 Length Required</title>
</head>
<body>
<h1>Length Required</h1>
<p>A request of the requested method GET requires a valid Content-length.</p>
</body>
</html>

412 Precondition Failed

HTTP/1.1 412 Precondition Failed
<html>
<head>
<title>412 Precondition Failed</title>
</head>
<body>
<h1>Precondition Failed</h1>
<p>The precondition on the request for the URL /e/412 evaluated to false.</p>
</body>
</html>

413 Request Entity Too Large

HTTP/1.1 413 Request Entity Too Large
Connection: close<html>
<head>
<title>413 Request Entity Too Large</title>
</head>
<body>
<h1>Request Entity Too Large</h1>
The requested resource<br />/e/413<br />does not allow request data with GET requests, or the amount of data provided in
the request exceeds the capacity limit.
</body>
</html>

414 Request-URI Too Large

HTTP/1.1 414 Request-URI Too Large
Connection: close<html>
<head>
<title>414 Request-URI Too Large</title>
</head>
<body>
<h1>Request-URI Too Large</h1>
<p>The requested URL's length exceeds the capacity
    limit for this server.</p>
</body>
</html>

415 Unsupported Media Type

HTTP/1.1 415 Unsupported Media Type<html>
<head>
<title>415 Unsupported Media Type</title>
</head>
<body>
<h1>Unsupported Media Type</h1>
<p>The supplied request data is not in a format
    acceptable for processing by this resource.</p>
</body>
</html>

416 Requested Range Not Satisfiable

HTTP/1.1 416 Requested Range Not Satisfiable

417 Expectation Failed

HTTP/1.1 417 Expectation Failed<html>
<head>
<title>417 Expectation Failed</title>
</head>
<body>
<h1>Expectation Failed</h1>
<p>The expectation given in the Expect request-header
    field could not be met by this server.</p>
<p>The client sent<pre>
    Expect: </p>
</body>
</html>

418 I'm a teapot

HTTP/1.1 418 I'm a teapot<html>
<head>
<title>418 I'm a teapot</title>
</head>
<body>
<h1>I'm a teapot</h1>
<p>Unfortunately this coffee machine is out of coffee.</p>
</body>
</html>

419 unused

HTTP/1.1 419 unused<html>
<head>
<title>419 unused</title>
</head>
<body>
<h1>unused</h1>
<p>The server encountered an internal error or misconfigurationand was unable to complete your request.</p>
<p>Please contact the server administrator, a@s.com and inform them of the time the error occurred, and anything you might have done that may have caused the error.</p>
<p>More information about this error may be available in the server error log.</p>
</body>
</html>

420 unused

HTTP/1.1 420 unused<html>
<head>
<title>420 unused</title>
</head>
<body>
<h1>unused</h1>
<p>The server encountered an internal error or misconfigurationand was unable to complete your request.</p>
<p>Please contact the server administrator, a@s.com and inform them of the time the error occurred, and anything you might have done that may have caused the error.</p>
<p>More information about this error may be available in the server error log.</p>
</body>
</html>

421 unused

HTTP/1.1 421 unused<html>
<head>
<title>421 unused</title>
</head>
<body>
<h1>unused</h1>
<p>The server encountered an internal error or misconfigurationand was unable to complete your request.</p>
<p>Please contact the server administrator, a@s.com and inform them of the time the error occurred, and anything you might have done that may have caused the error.</p>
<p>More information about this error may be available in the server error log.</p>
</body>
</html>

422 Unprocessable Entity

HTTP/1.1 422 Unprocessable Entity<html>
<head>
<title>422 Unprocessable Entity</title>
</head>
<body>
<h1>Unprocessable Entity</h1>
<p>The server understands the media type of the
    request entity, but was unable to process the
    contained instructions.</p>
</body>
</html>

423 Locked

HTTP/1.1 423 Locked<html>
<head>
<title>423 Locked</title>
</head>
<body>
<h1>Locked</h1>
<p>The requested resource is currently locked.
    The lock must be released or proper identification
    given before the method can be applied.</p>
</body>
</html>

424 Failed Dependency

HTTP/1.1 424 Failed Dependency<html>
<head>
<title>424 Failed Dependency</title>
</head>
<body>
<h1>Failed Dependency</h1>
<p>The method could not be performed on the resource
    because the requested action depended on another
    action and that other action failed.</p>
</body>
</html>

425 No code

HTTP/1.1 425 No code<html>
<head>
<title>425 No code</title>
</head>
<body>
<h1>No code</h1>
<p>The server encountered an internal error or misconfigurationand was unable to complete your request.</p>
<p>Please contact the server administrator, a@s.com and inform them of the time the error occurred, and anything you might have done that may have caused the error.</p>
<p>More information about this error may be available in the server error log.</p>
</body>
</html>

426 Upgrade Required

HTTP/1.1 426 Upgrade Required<html>
<head>
<title>426 Upgrade Required</title>
</head>
<body>
<h1>Upgrade Required</h1>
<p>The requested resource can only be retrieved
    using SSL.  The server is willing to upgrade the current
    connection to SSL, but your client doesn't support it.
    Either upgrade your client, or try requesting the page
    using https:// </p>
</body>
</html>

500 Internal Server Error

HTTP/1.1 500 Internal Server Error
Connection: close<html>
<head>
<title>500 Internal Server Error</title>
</head>
<body>
<h1>Internal Server Error</h1>
<p>The server encountered an internal error or misconfigurationand was unable to complete your request.</p>
<p>Please contact the server administrator, a@s.com and inform them of the time the error occurred, and anything you might have done that may have caused the error.</p>
<p>More information about this error may be available in the server error log.</p>
<p>Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.</p>
</body>
</html>

501 Method Not Implemented

HTTP/1.1 501 Method Not Implemented
Allow: TRACE
Connection: close<html>
<head>
<title>501 Method Not Implemented</title>
</head>
<body>
<h1>Method Not Implemented</h1>
<p>GET to /e/501 not supported.</p>
</body>
</html>

502 Bad Gateway

HTTP/1.1 502 Bad Gateway
X-Pad: avoid browser bug<html>
<head>
<title>502 Bad Gateway</title>
</head>
<body>
<h1>Bad Gateway</h1>
<p>The proxy server received an invalid
    response from an upstream server.</p>
</body>
</html>

503 Service Temporarily Unavailable

HTTP/1.1 503 Service Temporarily Unavailable
Connection: close<html>
<head>
<title>503 Service Temporarily Unavailable</title>
</head>
<body>
<h1>Service Temporarily Unavailable</h1>
<p>The server is temporarily unable to service your
    request due to maintenance downtime or capacity
    problems. Please try again later.</p>
</body>
</html>

504 Gateway Time-out

HTTP/1.1 504 Gateway Time-out<html>
<head>
<title>504 Gateway Time-out</title>
</head>
<body>
<h1>Gateway Time-out</h1>
<p>The proxy server did not receive a timely response
    from the upstream server.</p>
</body>
</html>

505 HTTP Version Not Supported

HTTP/1.1 505 HTTP Version Not Supported<html>
<head>
<title>505 HTTP Version Not Supported</title>
</head>
<body>
<h1>HTTP Version Not Supported</h1>
<p>The server encountered an internal error or misconfigurationand was unable to complete your request.</p>
<p>Please contact the server administrator, a@s.com and inform them of the time the error occurred, and anything you might have done that may have caused the error.</p>
<p>More information about this error may be available in the server error log.</p>
</body>
</html>

506 Variant Also Negotiates

HTTP/1.1 506 Variant Also Negotiates<html>
<head>
<title>506 Variant Also Negotiates</title>
</head>
<body>
<h1>Variant Also Negotiates</h1>
<p>A variant for the requested resource
    <pre>
    /e/506
    </pre>
    is itself a negotiable resource. This indicates a configuration error.</p>
</body>
</html>

507 Insufficient Storage

HTTP/1.1 507 Insufficient Storage<html>
<head>
<title>507 Insufficient Storage</title>
</head>
<body>
<h1>Insufficient Storage</h1>
<p>The method could not be performed on the resource
    because the server is unable to store the
    representation needed to successfully complete the
    request.  There is insufficient free space left in
    your storage allocation.</p>
</body>
</html>

508 unused

HTTP/1.1 508 unused<html>
<head>
<title>508 unused</title>
</head>
<body>
<h1>unused</h1>
<p>The server encountered an internal error or misconfigurationand was unable to complete your request.</p>
<p>Please contact the server administrator, a@s.com and inform them of the time the error occurred, and anything you might have done that may have caused the error.</p>
<p>More information about this error may be available in the server error log.</p>
</body>
</html>

509 unused

HTTP/1.1 509 unused
<html>
<head>
<title>509 unused</title>
</head>
<body>
<h1>unused</h1>
<p>The server encountered an internal error or misconfigurationand was unable to complete your request.</p>
<p>Please contact the server administrator, a@s.com and inform them of the time the error occurred, and anything you might have done that may have caused the error.</p>
<p>More information about this error may be available in the server error log.</p>
</body>
</html>

510 Not Extended

HTTP/1.1 510 Not Extended
X-Pad: avoid browser bug
<html>
<head>
<title>510 Not Extended</title>
</head>
<body>
<h1>Not Extended</h1>
<p>A mandatory extension policy in the request is not
    accepted by the server for this resource.</p>
</body>
</html>

Apache Source Code

httpd.h

From httpd.h

/**
* The size of the static array in http_protocol.c for storing
* all of the potential response status-lines (a sparse table).
* A future version should dynamically generate the apr_table_t at startup.
*/
#define RESPONSE_CODES 57
#define HTTP_CONTINUE            100
#define HTTP_SWITCHING_PROTOCOLS       101
#define HTTP_PROCESSING          102
#define HTTP_OK              200
#define HTTP_CREATED             201
#define HTTP_ACCEPTED            202
#define HTTP_NON_AUTHORITATIVE       203
#define HTTP_NO_CONTENT          204
#define HTTP_RESET_CONTENT         205
#define HTTP_PARTIAL_CONTENT         206
#define HTTP_MULTI_STATUS          207
#define HTTP_MULTIPLE_CHOICES        300
#define HTTP_MOVED_PERMANENTLY       301
 
#define HTTP_MOVED_TEMPORARILY       302
#define HTTP_SEE_OTHER           303
#define HTTP_NOT_MODIFIED          304
#define HTTP_USE_PROXY           305
#define HTTP_TEMPORARY_REDIRECT      307
#define HTTP_BAD_REQUEST           400
#define HTTP_UNAUTHORIZED          401
#define HTTP_PAYMENT_REQUIRED        402
#define HTTP_FORBIDDEN           403
#define HTTP_NOT_FOUND           404
#define HTTP_METHOD_NOT_ALLOWED      405
#define HTTP_NOT_ACCEPTABLE        406
#define HTTP_PROXY_AUTHENTICATION_REQUIRED 407
#define HTTP_REQUEST_TIME_OUT        408
#define HTTP_CONFLICT            409
#define HTTP_GONE              410
#define HTTP_LENGTH_REQUIRED         411
#define HTTP_PRECONDITION_FAILED       412
#define HTTP_REQUEST_ENTITY_TOO_LARGE    413
#define HTTP_REQUEST_URI_TOO_LARGE     414
#define HTTP_UNSUPPORTED_MEDIA_TYPE    415
#define HTTP_RANGE_NOT_SATISFIABLE     416
#define HTTP_EXPECTATION_FAILED      417
#define HTTP_UNPROCESSABLE_ENTITY      422
#define HTTP_LOCKED            423
#define HTTP_FAILED_DEPENDENCY       424
#define HTTP_UPGRADE_REQUIRED        426
#define HTTP_INTERNAL_SERVER_ERROR     500
#define HTTP_NOT_IMPLEMENTED         501
#define HTTP_BAD_GATEWAY           502
#define HTTP_SERVICE_UNAVAILABLE       503
#define HTTP_GATEWAY_TIME_OUT        504
#define HTTP_VERSION_NOT_SUPPORTED     505
#define HTTP_VARIANT_ALSO_VARIES       506
#define HTTP_INSUFFICIENT_STORAGE      507
#define HTTP_NOT_EXTENDED          510
 
/** is the status code informational */
#define ap_is_HTTP_INFO(x)     (((x) >= 100)&&((x) < 200))
/** is the status code OK ?*/
#define ap_is_HTTP_SUCCESS(x)    (((x) >= 200)&&((x) < 300))
/** is the status code a redirect */
#define ap_is_HTTP_REDIRECT(x)   (((x) >= 300)&&((x) < 400))
/** is the status code a error (client or server) */
#define ap_is_HTTP_ERROR(x)    (((x) >= 400)&&((x) < 600))
/** is the status code a client error  */
#define ap_is_HTTP_CLIENT_ERROR(x) (((x) >= 400)&&((x) < 500))
/** is the status code a server error  */
#define ap_is_HTTP_SERVER_ERROR(x) (((x) >= 500)&&((x) < 600))
/** is the status code a (potentially) valid response code?  */
#define ap_is_HTTP_VALID_RESPONSE(x) (((x) >= 100)&&((x) < 600))
 
/** should the status code drop the connection */
#define ap_status_drops_connection(x) \
(((x) == HTTP_BAD_REQUEST)       || \
((x) == HTTP_REQUEST_TIME_OUT)    || \
((x) == HTTP_LENGTH_REQUIRED)     || \
((x) == HTTP_REQUEST_ENTITY_TOO_LARGE) || \
((x) == HTTP_REQUEST_URI_TOO_LARGE) || \
((x) == HTTP_INTERNAL_SERVER_ERROR) || \
((x) == HTTP_SERVICE_UNAVAILABLE) || \
((x) == HTTP_NOT_IMPLEMENTED))

HTTP_INFO

Is the status code (x) informational?

x >= 100 && x < 200

HTTP_SUCCESS

Is the status code (x) OK?

x >= 200 && x < 300

HTTP_REDIRECT

Is the status code (x) a redirect?

x >= 300 && x < 400

HTTP_ERROR

Is the status code (x) a error (client or server)?

x >= 400 && x < 600

HTTP_CLIENT_ERROR

Is the status code (x) a client error?

x >= 400 && x < 500

HTTP_SERVER_ERROR

Is the status code (x) a server error?

x >= 500 && x < 600

HTTP_VALID_RESPONSE

Is the status code (x) a (potentially) valid response code?

x >= 100 && x < 600

http_protocol.c

From http_protocol.c

static const char * status_lines[RESPONSE_CODES] =
static const char * const status_lines[RESPONSE_CODES] =
"100 Continue",
"101 Switching Protocols",
"102 Processing",
"200 OK",
"201 Created",
"202 Accepted",
"203 Non-Authoritative Information",
"204 No Content",
"205 Reset Content",
"206 Partial Content",
"207 Multi-Status",
"300 Multiple Choices",
"301 Moved Permanently",
"302 Found",
"303 See Other",
"304 Not Modified",
"305 Use Proxy",
"306 unused",
"307 Temporary Redirect",
"400 Bad Request",
"401 Authorization Required",
"402 Payment Required",
"403 Forbidden",
"404 Not Found",
"405 Method Not Allowed",
"406 Not Acceptable",
"407 Proxy Authentication Required",
"408 Request Time-out",
"409 Conflict",
"410 Gone",
"411 Length Required",
"412 Precondition Failed",
"413 Request Entity Too Large",
"414 Request-URI Too Large",
"415 Unsupported Media Type",
"416 Requested Range Not Satisfiable",
"417 Expectation Failed",
"418 unused",
"419 unused",
"420 unused",
"421 unused",
"422 Unprocessable Entity",
"423 Locked",
"424 Failed Dependency",
"425 No code",
"426 Upgrade Required",
"500 Internal Server Error",
"501 Method Not Implemented",
"502 Bad Gateway",
"503 Service Temporarily Unavailable",
"504 Gateway Time-out",
"505 HTTP Version Not Supported",
"506 Variant Also Negotiates",
"507 Insufficient Storage",
"508 unused",
"509 unused",
"510 Not Extended"

IANA HTTP Status Code Registry

WordPress 2.8 Changes

I just learned that my modification to the WordPress core was accepted and will be implemented for version 2.8! This may mean WordPress is the only 100% HTTP/1.1 compliant software on the net! Below is the new list (I thought someone out there could use the php array) and as you can see, unfortunately418 I'm a teapotdidn't make it ;)

$wp_header_to_desc = array(
  100 => 'Continue',
  101 => 'Switching Protocols',
  102 => 'Processing',
 
  200 => 'OK',
  201 => 'Created',
  202 => 'Accepted',
  203 => 'Non-Authoritative Information',
  204 => 'No Content',
  205 => 'Reset Content',
  206 => 'Partial Content',
  207 => 'Multi-Status',
  226 => 'IM Used',
 
  300 => 'Multiple Choices',
  301 => 'Moved Permanently',
  302 => 'Found',
  303 => 'See Other',
  304 => 'Not Modified',
  305 => 'Use Proxy',
  306 => 'Reserved',
  307 => 'Temporary Redirect',
 
  400 => 'Bad Request',
  401 => 'Unauthorized',
  402 => 'Payment Required',
  403 => 'Forbidden',
  404 => 'Not Found',
  405 => 'Method Not Allowed',
  406 => 'Not Acceptable',
  407 => 'Proxy Authentication Required',
  408 => 'Request Timeout',
  409 => 'Conflict',
  410 => 'Gone',
  411 => 'Length Required',
  412 => 'Precondition Failed',
  413 => 'Request Entity Too Large',
  414 => 'Request-URI Too Long',
  415 => 'Unsupported Media Type',
  416 => 'Requested Range Not Satisfiable',
  417 => 'Expectation Failed',
  422 => 'Unprocessable Entity',
  423 => 'Locked',
  424 => 'Failed Dependency',
  426 => 'Upgrade Required',
 
  500 => 'Internal Server Error',
  501 => 'Not Implemented',
  502 => 'Bad Gateway',
  503 => 'Service Unavailable',
  504 => 'Gateway Timeout',
  505 => 'HTTP Version Not Supported',
  506 => 'Variant Also Negotiates',
  507 => 'Insufficient Storage',
  510 => 'Not Extended'
);

RIPE WHOIS

All the status codes are standard HTTP codes ( http://www.iana.org/assignments/http-status-codes ).

Clients should avoid any form of coupling with the the text/plain error message contained in response body since it may change between different releases of the API and is only intended as a starting point for indentifying the real causes of the exception event.

The following table gives a brief description of the mapping between standard Whois V.3 responses and the related REST services status codes. Consider this table as just an example of the error mapping strategy, it may change with future releases.

Clients will have to define error messages generic enough to represent the four main error conditions, that are Bad Request, Forbidden, Not Found and Internal Server Error.

For example a possible mapping for client side error messages may be:

Helpful HTTP Links

1. IANA registry
2. Hyper Text Coffee Pot Control Protocol (HTCPCP/1.0)
3. Adobe Flash status code definitions (ie 408)
4. Microsoft Internet Information Server Status Codes and Sub-Codes
5. httplint
6. HTTP Headers, brief intro.
7. Common User-Agent Issues
8. [RFC2295] Holtman, K. and A.H. Mutz , " Transparent Content Negotiation in HTTP ", RFC 2295, March 1998.
9. [RFC2518] Goland, Y. , Whitehead, E. , Faizi, A. , Carter, S.R. , and D. Jensen , " HTTP Extensions for Distributed Authoring -- WEBDAV ", RFC 2518, February 1999.
10. [RFC2616] Fielding, R. , Gettys, J. , Mogul, J. , Frystyk, H. , Masinter, L. , Leach, P. , and T. Berners-Lee , " Hypertext Transfer Protocol -- HTTP/1.1 ", RFC 2616, June 1999.
11. [RFC2774] Nielsen, H. , Leach, P. , and S. Lawrence , " An HTTP Extension Framework ", RFC 2774, February 2000.
12. [RFC2817] Khare, R. and S. Lawrence, " Upgrading to TLS Within HTTP/1.1 ", RFC 2817, May 2000.
13. [RFC3229] Mogul, J., Krishnamurthy, B., Douglis, F., Feldmann, A., Goland, Y., van Hoff, A., and D. Hellerstein, " Delta encoding in HTTP ", RFC 3229, January 2002.
14. [RFC4918] Dusseault, L., Ed. , " HTTP Extensions for Web Distributed Authoring and Versioning (WebDAV) ", RFC 4918, June 2007.

HTTP Status Codes and Htaccess ErrorDocuments originally appeared on AskApache.com

Back in the mid-90's I was doing a lot of war-dialing with modems (a more recent phenomenon is wardriving, the searching for wireless networks (Wi-Fi) from a moving vehicle. Wardriving was named after wardialing, since both techniques involve brute-force searches to find computer networks) and discovering all sorts of networks and machines, many of them were Unix and Solaris based public systems, and when I managed to gain access to the system and found myself staring at a unix shell I was very excited but also a total idiot. In those days of using the phone networks to research unknown systems it was very difficult for anyone to actually get the phone company to trace a call, so instead of what happens today where it is child's play to trace an IP address, back then it was a very real back-and-forth battle between the system admin and whoever was gaining access to their system.

Essentially, I would gain a shell or some kind of terminal, and just go at it trying to figure out what it could do, trying all kinds of commands. Inevitably this would eventually alert even the laziest admin and they would proceed to attempt to lock me out. It was great sport and extremely addictive. When my favorite system (a massive sun machine in the basement of a big library) finally locked me out and I couldn't get back in I went to my local library and got some reading material -- one of my favorites was the red hat bible. I was able to acquire my own computer and the first thing I did was install red hat linux onto it from the discs included with the book. For the next several years I was essentially offline, all we had at home was a modem and it was becoming difficult to locate any more systems in my area code.. I was into phreaking of course as well, but I never was able to make free long-distance war-dialing a reality.

So I just read the books and learned what I could. I would also goto the library when I could in order to use their machines which were connected to the internet (before aol it was much different than today's internet) and since my time was short I would download as many documents as I could so that I could read them offline. The TLDP documentation that we know today was around back then in various forms, and I read every HOWTO in the index, though not understanding half. The other big resource I found for really intense reading was the kernel documentation, which admitedly I still don't comprehend 1/4th of.. I try and peruse all the new documents when a new kernel is released, since the kernel is where all the real action is, hence the military authoritative name, and that is how I discovered one of the coolest features of Linux that I have found. TMPFS!

What I learned

I learned that with our present technology, which I try to keep somewhat updated on, using a mouse to point and click your way to a solution is always much much much slower than just getting dirty and writing straight code to a terminal. BTW, you know they are close (within 100 years) of enabling connection at the speed of thought. Yes it's a mind-meld between you and a super-computer AI to process it. That's the whole story behind popular Japanese anime like "Ghost in the Shell".

That's also a fundamental reason that certain vast segments of the computing world have a dislike of Microsoft, the way they build (to sell) their operating systems.. no open-code, which is their obvious #1 problem, and why they have a million viruses. Perhaps even a bigger issue some have with "the empire", is how they stuck this gooey, thats how you pronounce GUI - graphical user interface, in a way that tries to create multiple classes of people, those behind the scenes with all the control (they are a middleman between you and your real computer, for millions), and a second group of people on the outside, sheep - I believe they are referred to as sheep.

Cleanup Screenrc Files

You can run this command to get a wildly confusing screenrc file under control. You could have a heavily commented version, and then run this to create the actual... I like to start there but because the screenrc file is read in order, you should take out the 'sort'.

sed -e '/^#/d; s/^[\t\ ]*//g; /^[a-z]/I!d' /etc/screenrc|sort|tr -s ' \t' | tr -d '\015\032'

Read lots of .screenrc files

This is easy with Google's futuristic Code Searching Engine! I get excited about this search engine because it is sooo dope! Here's a search for files named .screenrc, thanks for this free tool Google, much love!

autodetach on
bufferfile $HOME/.screen/buffer
 
nethack on # print wackier status messages
chdir $HOME
password HJa4Dp4UIDlLA
 
setenv LC_CTYPE en_US.UTF-8
sorendition =s Gk
startup_message off
shell bash # use the default shell
shelltitle "$ |bash"
term screen-256color #By default, screen uses an 8-color terminal emulator. Use the following line to enable more colors, more-capable terminal emulator:
 
defmode 620
defmonitor off # turn monitoring on
defnonblock 5 # flaky/slow ssh lines
defscrollback 300
defutf8 on
hardcopydir ~/.hardcopy/screen_%y-%m-%d_%0c.%n
 
defbce on # erase background with current bg color
defencoding UTF-8
defflow auto # will force screen to process ^S/^Q
defflow on # disable Ctrl-S/Ctrl-Q "flow control"
defhstatus "screen: ^En (^Et)"
deflogin off
 
deflog off
logfile ~/.screen/screen_%y-%m-%d_%0c.%n
 
silencewait 15
vbell_msg " Wuff ---- Wuff!! "
 
activity "%C -> %n%f %t activity!"
bell "%C -> %n%f %t bell!~"
 
altscreen on # restore window contents after using (e.g.) vi
attrcolor b ".I" # allow bold colors - necessary for some reason
 
hardstatus on
hardstatus alwayslastline "[%02c] %`%-w%{=b bw}%n %t%{-}%+w %=%{..Lw} %H %{..g} %m/%d %C%a "
caption always "%{kG}%?%-Lw%?%{bw}%n*%f %t%?(%u)%?%{kG}%?%+Lw%?"
 
idle 3600 eval "screen nice -n 19 /opt/s/cmatrix" "idle 6400 detach"
 
msgwait 5 # 1 second messages
multiuser off
nonblock on # If a window goes unresponsive, don't block the whole session waiting for it.
pow_detach_msg "Screen session of $LOGNAME $:cr:$:nl:ended." # emulate .logout message
 
screen -h 500 -t 'bash' sh $HOME/welcome.sh
screen -h 0 -t 'MATRIX' nice -n 19 /opt/s/cmatrix
screen -h 0 -t 'WHO' sudo /opt/s/whowatch
screen -h 100 -t 'gator' sh $HOME/.ssh/start_control.sh
screen -h 100 -t 'gator' ssh gator sh ~/welcome.sh
screen -h 500 -t 'root' sudo bash -l
screen -h 0 -t 'MEM' nice -n 19 sh -c 'sleep 4 && tput civis; CLS=$`tput clear`; trap "tput cnorm; exit 0" 1 2 3; while :; do free -olt && sleep 2 && echo $CLS; done;'
screen -h 0 -t 'TOP' nice -n 19 sh -c 'sleep 4 && tput civis; CLS=$`tput clear`; trap "tput cnorm; exit 0" 1 2 3; while :; do top -b -n 1 -H -d 10 -c |sed "/$USER/!d" && echo $CLS; done;'
screen -h 0 -t 'NET' nice -n 19 sh -c 'while :; do /bin/netstat --numeric-ports -a -e --tcp |sort --key=4 && sleep 5; done;'
select 0
 
#select -h 100 -t 'log' 4 sudo sh -c 'nice tail -n 60 -s 10 -f /var/log/everything.log | ccze -A'
 
zombie "^[" # don't kill window after the process died

More on War Dialing

War dialing or wardialing is a technique of using a modem to automatically scan a list of telephone numbers, usually dialing every number in a local area code to search for computers, Bulletin board systems and fax machines. Hackers use the resulting lists for various purposes, hobbyists for exploration, and crackers - hackers that specialize in computer security - for password guessing.

A single wardialing call would involve calling an unknown number, and waiting for one or two rings, since answering computers usually pick up on the first ring. If the phone rings twice, the modem hangs up and tries the next number. If a modem or fax machine answers, the wardialer program makes a note of the number. If a human or answering machine answers, the wardialer program hangs up. Depending on the time of day, wardialing 10,000 numbers in a given area code might annoy dozens or hundreds of people, some who attempt and fail to answer a phone in two rings, and some who succeed, only to hear the wardialing modem's carrier tone and hang up. The repeated incoming calls are especially annoying to businesses that have many consecutively numbered lines in the exchange, such as used with a Centrex telephone system.

The popularity of wardialing in 1980s and 1990s prompted some states to enact legislation prohibiting the use of a device to dial telephone numbers without the intent of communicating with a person.

The name for this technique originated in the 1983 film WarGames. In the film, the protagonist programmed his computer to dial every telephone number in Sunnyvale, California to find other computer systems. 'WarGames Dialer' programs became common on bulletin board systems of the time, with file names often truncated to wardial.exe and the like due to length restrictions on such systems. Eventually, the etymology of the name fell behind as "war dialing" gained its own currency within computing culture.[1]

A more recent phenomenon is wardriving, the searching for wireless networks (Wi-Fi) from a moving vehicle. Wardriving was named after wardialing, since both techniques involve brute-force searches to find computer networks. The aim of wardriving is to collect information about wireless access points (not to be confused with piggybacking).

Similar to war dialing is a port scan under TCP/IP, which "dials" every TCP port of every IP address to find out what services are available. Unlike wardialing, however, a port scan will generally not disturb a human being when it tries an IP address, regardless of whether there is a computer responding on that address or not. Related to wardriving is warchalking, the practice of drawing chalk symbols in public places to advertise the availability of wireless networks. Despite its widespread coverage [in the news?], warchalking never particularly caught on as a popular activity.

The term is also used today by analogy for various sorts of exhaustive brute force attack against an authentication mechanism, such as a password. While a dictionary attack might involve trying each word in a dictionary as the password, "wardialing the password" would involve trying every possible password. Password protection systems are usually designed to make this impractical, by making the process slow and/or locking out an account for minutes or hours after some low number of wrong password entries.

War dialing is sometimes used as a synonym for demon dialing, a related technique which also involves automating a computer modem in order to repeatedly place telephone calls.

This page contains content by Author of Article from Wikipedia and is licensed under the GNU FDL.

Magic in the Terminal: Screen, Bash, and SSH originally appeared on AskApache.com