{ "content": [ { "type": "text", "text": "# getty (info)\n\n## NAME\n\nagetty - alternative Linux getty\n\n## SYNOPSIS\n\nagetty [options] port [baudrate...] [term]\n\n## DESCRIPTION\n\nagetty opens a tty port, prompts for a login name and invokes the\n/bin/login command. It is normally invoked by init(8).\n\n## Sections\n\n- **NAME**\n- **SYNOPSIS**\n- **DESCRIPTION**\n- **ARGUMENTS**\n- **OPTIONS** (22 subsections)\n- **EXAMPLE**\n- **SECURITY NOTICE**\n- **ISSUE FILES**\n- **FILES**\n- **BUGS**\n- **DIAGNOSTICS**\n- **AUTHORS**\n- **REPORTING BUGS**\n- **AVAILABILITY**\n\nUse structuredContent.sections for detailed options, examples, and full documentation.\n" } ], "structuredContent": { "command": "getty", "section": "", "mode": "info", "summary": "agetty - alternative Linux getty", "synopsis": "agetty [options] port [baudrate...] [term]", "tldr_summary": null, "tldr_examples": [], "tldr_source": null, "flags": [ { "flag": "-c", "long": "--noreset", "arg": null, "description": "Do not reset terminal cflags (control modes). See termios(3) for more details." }, { "flag": "-E", "long": "--remote", "arg": null, "description": "Typically the login(1) command is given a remote hostname when called by something such as telnetd(8). This option allows agetty to pass what it is using for a hostname to login(1) for use in utmp(5). See --host, login(1), and utmp(5). If the --host fakehost option is given, then an -h fakehost option and argument are added to the /bin/login command line. If the --nohostname option is given, then an -H option is added to the /bin/login command line. See --login-options. -f, --issue-file path Specifies a \":\" delimited list of files and directories to be displayed instead of /etc/issue (or other). All specified files and directories are displayed, missing or empty files are silently ignored. If the specified path is a directory then display all files with .issue file extension in version-sort order from the directory. This allows custom messages to be displayed on different terminals. The --noissue option will override this option." }, { "flag": "", "long": "--show-issue", "arg": null, "description": "Display the current issue file (or other) on the current terminal and exit. Use this option to review the current setting, it is not designed for any other purpose. Note that output may use some default or incomplete information as proper output depends on terminal and agetty command line." }, { "flag": "-h", "long": "--flow-control", "arg": null, "description": "Enable hardware (RTS/CTS) flow control. It is left up to the application to disable software (XON/XOFF) flow protocol where appropriate. -H, --host fakehost Write the specified fakehost into the utmp file. Normally, no login host is given, since agetty is used for local hardwired connections and consoles. However, this option can be useful for identifying terminal concentrators and the like." }, { "flag": "-i", "long": "--noissue", "arg": null, "description": "Do not display the contents of /etc/issue (or other) before writing the login prompt. Terminals or communications hardware may become confused when receiving lots of text at the wrong baud rate; dial-up scripts may fail if the login prompt is preceded by too much text. -I, --init-string initstring Set an initial string to be sent to the tty or modem before sending anything else. This may be used to initialize a modem. Non-printable characters may be sent by writing their octal code preceded by a backslash (\\). For example, to send a linefeed character (ASCII 10, octal 012), write \\12." }, { "flag": "-J", "long": "--noclear", "arg": null, "description": "Do not clear the screen before prompting for the login name. By default the screen is cleared. -l, --login-program loginprogram Invoke the specified loginprogram instead of /bin/login. This allows the use of a non-standard login program. Such a program could, for example, ask for a dial-up password or use a different password file. See --login-options." }, { "flag": "-L", "long": null, "arg": null, "description": "Control the CLOCAL line flag. The optional mode argument is 'auto', 'always' or 'never'. If the mode argument is omitted, then the default is 'always'. If the --local-line option is not given at all, then the default is 'auto'. always Forces the line to be a local line with no need for carrier detect. This can be useful when you have a locally attached terminal where the serial line does not set the carrier-detect signal. never Explicitly clears the CLOCAL flag from the line setting and the carrier-detect signal is expected on the line. auto The agetty default. Does not modify the CLOCAL setting and follows the setting enabled by the kernel." }, { "flag": "-m", "long": "--extract-baud", "arg": null, "description": "Try to extract the baud rate from the CONNECT status message produced by Hayes(tm)-compatible modems. These status messages are of the form: \"\". agetty assumes that the modem emits its status message at the same speed as specified with (the first) baudrate value on the command line. Since the --extract-baud feature may fail on heavily-loaded systems, you still should enable BREAK processing by enumerating all expected baud rates on the command line." }, { "flag": "", "long": "--list-speeds", "arg": null, "description": "Display supported baud rates. These are determined at compilation time." }, { "flag": "-n", "long": "--skip-login", "arg": null, "description": "Do not prompt the user for a login name. This can be used in connection with the --login-program option to invoke a non-standard login process such as a BBS system. Note that with the --skip-login option, agetty gets no input from the user who logs in and therefore will not be able to figure out parity, character size, and newline processing of the connection. It defaults to space parity, 7 bit characters, and ASCII CR (13) end-of-line character. Beware that the program that agetty starts (usually /bin/login) is run as root." }, { "flag": "-N", "long": "--nonewline", "arg": null, "description": "Do not print a newline before writing out /etc/issue. -o, --login-options loginoptions Options and arguments that are passed to login(1). Where \\u is replaced by the login name. For example: --login-options '-h darkstar -- \\u' See --autologin, --login-program and --remote. Please read the SECURITY NOTICE below before using this option." }, { "flag": "-p", "long": "--login-pause", "arg": null, "description": "Wait for any key before dropping to the login prompt. Can be combined with --autologin to save memory by lazily spawning shells. -r, --chroot directory Change root to the specified directory." }, { "flag": "-R", "long": "--hangup", "arg": null, "description": "Call vhangup(2) to do a virtual hangup of the specified terminal." }, { "flag": "-s", "long": "--keep-baud", "arg": null, "description": "Try to keep the existing baud rate. The baud rates from the command line are used when agetty receives a BREAK character. If another baud rates specified then the original baud rate is also saved to the end of the wanted baud rates list. This can be used to return to the original baud rate after unexpected BREAKs. -t, --timeout timeout Terminate if no user name could be read within timeout seconds. Use of this option with hardwired terminal lines is not recommended." }, { "flag": "-U", "long": "--detect-case", "arg": null, "description": "Turn on support for detecting an uppercase-only terminal. This setting will detect a login name containing only capitals as indicating an uppercase-only terminal and turn on some upper-to-lower case conversions. Note that this has no support for any Unicode characters." }, { "flag": "-w", "long": "--wait-cr", "arg": null, "description": "Wait for the user or the modem to send a carriage-return or a linefeed character before sending the /etc/issue file (or others) and the login prompt. This is useful with the --init-string option." }, { "flag": "", "long": "--nohints", "arg": null, "description": "Do not print hints about Num, Caps and Scroll Locks." }, { "flag": "", "long": "--nohostname", "arg": null, "description": "By default the hostname will be printed. With this option enabled, no hostname at all will be shown." }, { "flag": "", "long": "--long-hostname", "arg": null, "description": "By default the hostname is only printed until the first dot. With this option enabled, the fully qualified hostname by gethostname(3P) or (if not found) by getaddrinfo(3) is shown. --erase-chars string This option specifies additional characters that should be interpreted as a backspace (\"ignore the previous character\") when the user types the login name. The default additional 'erase' has been '#', but since util-linux 2.23 no additional erase characters are enabled by default. --kill-chars string This option specifies additional characters that should be interpreted as a kill (\"ignore all previous characters\") when the user types the login name. The default additional 'kill' has been '@', but since util-linux 2.23 no additional kill characters are enabled by default. --chdir directory Change directory before the login. --delay number Sleep seconds before open tty. --nice number Run login with this priority." }, { "flag": "", "long": "--reload", "arg": null, "description": "Ask all running agetty instances to reload and update their displayed prompts, if the user has not yet commenced logging in. After doing so the command will exit. This feature might be unsupported on systems without Linux inotify(7)." }, { "flag": "", "long": "--version", "arg": null, "description": "Display version information and exit." }, { "flag": "", "long": "--help", "arg": null, "description": "Display help text and exit." } ], "examples": [ "This section shows examples for the process field of an entry in the", "/etc/inittab file. You'll have to prepend appropriate values for the", "other fields. See inittab(5) for more details.", "For a hardwired line or a console tty:", "/sbin/agetty 9600 ttyS1", "For a directly connected terminal without proper carrier-detect wiring", "(try this if your terminal just sleeps instead of giving you a", "password: prompt):", "/sbin/agetty --local-line 9600 ttyS1 vt100", "For an old-style dial-in line with a 9600/2400/1200 baud modem:", "/sbin/agetty --extract-baud --timeout 60 ttyS1 9600,2400,1200", "For a Hayes modem with a fixed 115200 bps interface to the machine (the", "example init string turns off modem echo and result codes, makes", "modem/computer DCD track modem/modem DCD, makes a DTR drop cause a", "disconnection, and turns on auto-answer after 1 ring):", "/sbin/agetty --wait-cr --init-string 'ATE0Q1&D2&C1S0=1\\015'", "115200 ttyS1" ], "see_also": [], "section_outline": [ { "name": "NAME", "lines": 2, "subsections": [] }, { "name": "SYNOPSIS", "lines": 2, "subsections": [] }, { "name": "DESCRIPTION", "lines": 38, "subsections": [] }, { "name": "ARGUMENTS", "lines": 29, "subsections": [] }, { "name": "OPTIONS", "lines": 14, "subsections": [ { "name": "-c, --noreset", "lines": 3, "flag": "-c", "long": "--noreset" }, { "name": "-E, --remote", "lines": 22, "flag": "-E", "long": "--remote" }, { "name": "--show-issue", "lines": 6, "long": "--show-issue" }, { "name": "-h, --flow-control", "lines": 10, "flag": "-h", "long": "--flow-control" }, { "name": "-i, --noissue", "lines": 13, "flag": "-i", "long": "--noissue" }, { "name": "-J, --noclear", "lines": 9, "flag": "-J", "long": "--noclear" }, { "name": "-L, --local-line[=mode]", "lines": 19, "flag": "-L" }, { "name": "-m, --extract-baud", "lines": 10, "flag": "-m", "long": "--extract-baud" }, { "name": "--list-speeds", "lines": 3, "long": "--list-speeds" }, { "name": "-n, --skip-login", "lines": 10, "flag": "-n", "long": "--skip-login" }, { "name": "-N, --nonewline", "lines": 12, "flag": "-N", "long": "--nonewline" }, { "name": "-p, --login-pause", "lines": 6, "flag": "-p", "long": "--login-pause" }, { "name": "-R, --hangup", "lines": 2, "flag": "-R", "long": "--hangup" }, { "name": "-s, --keep-baud", "lines": 10, "flag": "-s", "long": "--keep-baud" }, { "name": "-U, --detect-case", "lines": 6, "flag": "-U", "long": "--detect-case" }, { "name": "-w, --wait-cr", "lines": 4, "flag": "-w", "long": "--wait-cr" }, { "name": "--nohints", "lines": 2, "long": "--nohints" }, { "name": "--nohostname", "lines": 3, "long": "--nohostname" }, { "name": "--long-hostname", "lines": 27, "long": "--long-hostname" }, { "name": "--reload", "lines": 5, "long": "--reload" }, { "name": "--version", "lines": 2, "long": "--version" }, { "name": "--help", "lines": 2, "long": "--help" } ] }, { "name": "EXAMPLE", "lines": 26, "subsections": [] }, { "name": "SECURITY NOTICE", "lines": 13, "subsections": [] }, { "name": "ISSUE FILES", "lines": 107, "subsections": [] }, { "name": "FILES", "lines": 15, "subsections": [] }, { "name": "BUGS", "lines": 12, "subsections": [] }, { "name": "DIAGNOSTICS", "lines": 6, "subsections": [] }, { "name": "AUTHORS", "lines": 6, "subsections": [] }, { "name": "REPORTING BUGS", "lines": 3, "subsections": [] }, { "name": "AVAILABILITY", "lines": 5, "subsections": [] } ], "sections": { "NAME": { "content": "agetty - alternative Linux getty\n", "subsections": [] }, "SYNOPSIS": { "content": "agetty [options] port [baudrate...] [term]\n", "subsections": [] }, "DESCRIPTION": { "content": "agetty opens a tty port, prompts for a login name and invokes the\n/bin/login command. It is normally invoked by init(8).\n\nagetty has several non-standard features that are useful for hardwired\nand for dial-in lines:\n\no Adapts the tty settings to parity bits and to erase, kill,\nend-of-line and uppercase characters when it reads a login name.\nThe program can handle 7-bit characters with even, odd, none or\nspace parity, and 8-bit characters with no parity. The following\nspecial characters are recognized: Control-U (kill); DEL and\nbackspace (erase); carriage return and line feed (end of line). See\nalso the --erase-chars and --kill-chars options.\n\no Optionally deduces the baud rate from the CONNECT messages produced\nby Hayes(tm)-compatible modems.\n\no Optionally does not hang up when it is given an already opened line\n(useful for call-back applications).\n\no Optionally does not display the contents of the /etc/issue file.\n\no Optionally displays an alternative issue files or directories\ninstead of /etc/issue or /etc/issue.d.\n\no Optionally does not ask for a login name.\n\no Optionally invokes a non-standard login program instead of\n/bin/login.\n\no Optionally turns on hardware flow control.\n\no Optionally forces the line to be local with no need for carrier\ndetect.\n\nThis program does not use the /etc/gettydefs (System V) or\n/etc/gettytab (SunOS 4) files.\n", "subsections": [] }, "ARGUMENTS": { "content": "port\nA path name relative to the /dev directory. If a \"-\" is specified,\nagetty assumes that its standard input is already connected to a\ntty port and that a connection to a remote user has already been\nestablished.\n\nUnder System V, a \"-\" port argument should be preceded by a \"--\".\n\nbaudrate,...\nA comma-separated list of one or more baud rates. Each time agetty\nreceives a BREAK character it advances through the list, which is\ntreated as if it were circular.\n\nBaud rates should be specified in descending order, so that the\nnull character (Ctrl-@) can also be used for baud-rate switching.\n\nThis argument is optional and unnecessary for virtual terminals.\n\nThe default for serial terminals is keep the current baud rate (see\n--keep-baud) and if unsuccessful then default to '9600'.\n\nterm\nThe value to be used for the TERM environment variable. This\noverrides whatever init(1) may have set, and is inherited by login\nand the shell.\n\nThe default is 'vt100', or 'linux' for Linux on a virtual terminal,\nor 'hurd' for GNU Hurd on a virtual terminal.\n", "subsections": [] }, "OPTIONS": { "content": "-8, --8bits\nAssume that the tty is 8-bit clean, hence disable parity detection.\n\n-a, --autologin username\nAutomatically log in the specified user without asking for a\nusername or password. Using this option causes an -f username\noption and argument to be added to the /bin/login command line. See\n--login-options, which can be used to modify this option's\nbehavior.\n\nNote that --autologin may affect the way in which getty initializes\nthe serial line, because on auto-login agetty does not read from\nthe line and it has no opportunity optimize the line setting.\n", "subsections": [ { "name": "-c, --noreset", "content": "Do not reset terminal cflags (control modes). See termios(3) for\nmore details.\n", "flag": "-c", "long": "--noreset" }, { "name": "-E, --remote", "content": "Typically the login(1) command is given a remote hostname when\ncalled by something such as telnetd(8). This option allows agetty\nto pass what it is using for a hostname to login(1) for use in\nutmp(5). See --host, login(1), and utmp(5).\n\nIf the --host fakehost option is given, then an -h fakehost option\nand argument are added to the /bin/login command line.\n\nIf the --nohostname option is given, then an -H option is added to\nthe /bin/login command line.\n\nSee --login-options.\n\n-f, --issue-file path\nSpecifies a \":\" delimited list of files and directories to be\ndisplayed instead of /etc/issue (or other). All specified files and\ndirectories are displayed, missing or empty files are silently\nignored. If the specified path is a directory then display all\nfiles with .issue file extension in version-sort order from the\ndirectory. This allows custom messages to be displayed on different\nterminals. The --noissue option will override this option.\n", "flag": "-E", "long": "--remote" }, { "name": "--show-issue", "content": "Display the current issue file (or other) on the current terminal\nand exit. Use this option to review the current setting, it is not\ndesigned for any other purpose. Note that output may use some\ndefault or incomplete information as proper output depends on\nterminal and agetty command line.\n", "long": "--show-issue" }, { "name": "-h, --flow-control", "content": "Enable hardware (RTS/CTS) flow control. It is left up to the\napplication to disable software (XON/XOFF) flow protocol where\nappropriate.\n\n-H, --host fakehost\nWrite the specified fakehost into the utmp file. Normally, no login\nhost is given, since agetty is used for local hardwired connections\nand consoles. However, this option can be useful for identifying\nterminal concentrators and the like.\n", "flag": "-h", "long": "--flow-control" }, { "name": "-i, --noissue", "content": "Do not display the contents of /etc/issue (or other) before writing\nthe login prompt. Terminals or communications hardware may become\nconfused when receiving lots of text at the wrong baud rate;\ndial-up scripts may fail if the login prompt is preceded by too\nmuch text.\n\n-I, --init-string initstring\nSet an initial string to be sent to the tty or modem before sending\nanything else. This may be used to initialize a modem.\nNon-printable characters may be sent by writing their octal code\npreceded by a backslash (\\). For example, to send a linefeed\ncharacter (ASCII 10, octal 012), write \\12.\n", "flag": "-i", "long": "--noissue" }, { "name": "-J, --noclear", "content": "Do not clear the screen before prompting for the login name. By\ndefault the screen is cleared.\n\n-l, --login-program loginprogram\nInvoke the specified loginprogram instead of /bin/login. This\nallows the use of a non-standard login program. Such a program\ncould, for example, ask for a dial-up password or use a different\npassword file. See --login-options.\n", "flag": "-J", "long": "--noclear" }, { "name": "-L, --local-line[=mode]", "content": "Control the CLOCAL line flag. The optional mode argument is 'auto',\n'always' or 'never'. If the mode argument is omitted, then the\ndefault is 'always'. If the --local-line option is not given at\nall, then the default is 'auto'.\n\nalways\nForces the line to be a local line with no need for carrier\ndetect. This can be useful when you have a locally attached\nterminal where the serial line does not set the carrier-detect\nsignal.\n\nnever\nExplicitly clears the CLOCAL flag from the line setting and the\ncarrier-detect signal is expected on the line.\n\nauto\nThe agetty default. Does not modify the CLOCAL setting and\nfollows the setting enabled by the kernel.\n", "flag": "-L" }, { "name": "-m, --extract-baud", "content": "Try to extract the baud rate from the CONNECT status message\nproduced by Hayes(tm)-compatible modems. These status messages are\nof the form: \"\". agetty assumes that the modem\nemits its status message at the same speed as specified with (the\nfirst) baudrate value on the command line.\n\nSince the --extract-baud feature may fail on heavily-loaded\nsystems, you still should enable BREAK processing by enumerating\nall expected baud rates on the command line.\n", "flag": "-m", "long": "--extract-baud" }, { "name": "--list-speeds", "content": "Display supported baud rates. These are determined at compilation\ntime.\n", "long": "--list-speeds" }, { "name": "-n, --skip-login", "content": "Do not prompt the user for a login name. This can be used in\nconnection with the --login-program option to invoke a non-standard\nlogin process such as a BBS system. Note that with the --skip-login\noption, agetty gets no input from the user who logs in and\ntherefore will not be able to figure out parity, character size,\nand newline processing of the connection. It defaults to space\nparity, 7 bit characters, and ASCII CR (13) end-of-line character.\nBeware that the program that agetty starts (usually /bin/login) is\nrun as root.\n", "flag": "-n", "long": "--skip-login" }, { "name": "-N, --nonewline", "content": "Do not print a newline before writing out /etc/issue.\n\n-o, --login-options loginoptions\nOptions and arguments that are passed to login(1). Where \\u is\nreplaced by the login name. For example:\n\n--login-options '-h darkstar -- \\u'\n\nSee --autologin, --login-program and --remote.\n\nPlease read the SECURITY NOTICE below before using this option.\n", "flag": "-N", "long": "--nonewline" }, { "name": "-p, --login-pause", "content": "Wait for any key before dropping to the login prompt. Can be\ncombined with --autologin to save memory by lazily spawning shells.\n\n-r, --chroot directory\nChange root to the specified directory.\n", "flag": "-p", "long": "--login-pause" }, { "name": "-R, --hangup", "content": "Call vhangup(2) to do a virtual hangup of the specified terminal.\n", "flag": "-R", "long": "--hangup" }, { "name": "-s, --keep-baud", "content": "Try to keep the existing baud rate. The baud rates from the command\nline are used when agetty receives a BREAK character. If another\nbaud rates specified then the original baud rate is also saved to\nthe end of the wanted baud rates list. This can be used to return\nto the original baud rate after unexpected BREAKs.\n\n-t, --timeout timeout\nTerminate if no user name could be read within timeout seconds. Use\nof this option with hardwired terminal lines is not recommended.\n", "flag": "-s", "long": "--keep-baud" }, { "name": "-U, --detect-case", "content": "Turn on support for detecting an uppercase-only terminal. This\nsetting will detect a login name containing only capitals as\nindicating an uppercase-only terminal and turn on some\nupper-to-lower case conversions. Note that this has no support for\nany Unicode characters.\n", "flag": "-U", "long": "--detect-case" }, { "name": "-w, --wait-cr", "content": "Wait for the user or the modem to send a carriage-return or a\nlinefeed character before sending the /etc/issue file (or others)\nand the login prompt. This is useful with the --init-string option.\n", "flag": "-w", "long": "--wait-cr" }, { "name": "--nohints", "content": "Do not print hints about Num, Caps and Scroll Locks.\n", "long": "--nohints" }, { "name": "--nohostname", "content": "By default the hostname will be printed. With this option enabled,\nno hostname at all will be shown.\n", "long": "--nohostname" }, { "name": "--long-hostname", "content": "By default the hostname is only printed until the first dot. With\nthis option enabled, the fully qualified hostname by\ngethostname(3P) or (if not found) by getaddrinfo(3) is shown.\n\n--erase-chars string\nThis option specifies additional characters that should be\ninterpreted as a backspace (\"ignore the previous character\") when\nthe user types the login name. The default additional 'erase' has\nbeen '#', but since util-linux 2.23 no additional erase characters\nare enabled by default.\n\n--kill-chars string\nThis option specifies additional characters that should be\ninterpreted as a kill (\"ignore all previous characters\") when the\nuser types the login name. The default additional 'kill' has been\n'@', but since util-linux 2.23 no additional kill characters are\nenabled by default.\n\n--chdir directory\nChange directory before the login.\n\n--delay number\nSleep seconds before open tty.\n\n--nice number\nRun login with this priority.\n", "long": "--long-hostname" }, { "name": "--reload", "content": "Ask all running agetty instances to reload and update their\ndisplayed prompts, if the user has not yet commenced logging in.\nAfter doing so the command will exit. This feature might be\nunsupported on systems without Linux inotify(7).\n", "long": "--reload" }, { "name": "--version", "content": "Display version information and exit.\n", "long": "--version" }, { "name": "--help", "content": "Display help text and exit.\n", "long": "--help" } ] }, "EXAMPLE": { "content": "This section shows examples for the process field of an entry in the\n/etc/inittab file. You'll have to prepend appropriate values for the\nother fields. See inittab(5) for more details.\n\nFor a hardwired line or a console tty:\n\n/sbin/agetty 9600 ttyS1\n\nFor a directly connected terminal without proper carrier-detect wiring\n(try this if your terminal just sleeps instead of giving you a\npassword: prompt):\n\n/sbin/agetty --local-line 9600 ttyS1 vt100\n\nFor an old-style dial-in line with a 9600/2400/1200 baud modem:\n\n/sbin/agetty --extract-baud --timeout 60 ttyS1 9600,2400,1200\n\nFor a Hayes modem with a fixed 115200 bps interface to the machine (the\nexample init string turns off modem echo and result codes, makes\nmodem/computer DCD track modem/modem DCD, makes a DTR drop cause a\ndisconnection, and turns on auto-answer after 1 ring):\n\n/sbin/agetty --wait-cr --init-string 'ATE0Q1&D2&C1S0=1\\015'\n115200 ttyS1\n", "subsections": [] }, "SECURITY NOTICE": { "content": "If you use the --login-program and --login-options options, be aware\nthat a malicious user may try to enter lognames with embedded options,\nwhich then get passed to the used login program. Agetty does check for\na leading \"-\" and makes sure the logname gets passed as one parameter\n(so embedded spaces will not create yet another parameter), but\ndepending on how the login binary parses the command line that might\nnot be sufficient. Check that the used login program cannot be abused\nthis way.\n\nSome programs use \"--\" to indicate that the rest of the command line\nshould not be interpreted as options. Use this feature if available by\npassing \"--\" before the username gets passed by \\u.\n", "subsections": [] }, "ISSUE FILES": { "content": "The default issue file is /etc/issue. If the file exists, then agetty\nalso checks for /etc/issue.d directory. The directory is optional\nextension to the default issue file and content of the directory is\nprinted after /etc/issue content. If the /etc/issue does not exist,\nthen the directory is ignored. All files with .issue extension from the\ndirectory are printed in version-sort order. The directory can be used\nto maintain 3rd-party messages independently on the primary system\n/etc/issue file.\n\nSince version 2.35 additional locations for issue file and directory\nare supported. If the default /etc/issue does not exist, then agetty\nchecks for /run/issue and /run/issue.d, thereafter for /usr/lib/issue\nand /usr/lib/issue.d. The directory /etc is expected for host specific\nconfiguration, /run is expected for generated stuff and /usr/lib for\nstatic distribution maintained configuration.\n\nThe default path maybe overridden by --issue-file option. In this case\nspecified path has to be file or directory and all the default issue\nfile and directory locations are ignored.\n\nThe issue file feature can be completely disabled by --noissue option.\n\nIt is possible to review the current issue file by agetty --show-issue\non the current terminal.\n\nThe issue files may contain certain escape codes to display the system\nname, date, time et cetera. All escape codes consist of a backslash (\\)\nimmediately followed by one of the characters listed below.\n\n4 or 4{interface}\nInsert the IPv4 address of the specified network interface (for\nexample: \\4{eth0}). If the interface argument is not specified,\nthen select the first fully configured (UP, non-LOCALBACK, RUNNING)\ninterface. If not any configured interface is found, fall back to\nthe IP address of the machine's hostname.\n\n6 or 6{interface}\nThe same as \\4 but for IPv6.\n\nb\nInsert the baudrate of the current line.\n\nd\nInsert the current date.\n\ne or e{name}\nTranslate the human-readable name to an escape sequence and insert\nit (for example: \\e{red}Alert text.\\e{reset}). If the name argument\nis not specified, then insert \\033. The currently supported names\nare: black, blink, blue, bold, brown, cyan, darkgray, gray, green,\nhalfbright, lightblue, lightcyan, lightgray, lightgreen,\nlightmagenta, lightred, magenta, red, reset, reverse, yellow and\nwhite. All unknown names are silently ignored.\n\ns\nInsert the system name (the name of the operating system). Same as\n'uname -s'. See also the \\S escape code.\n\nS or S{VARIABLE}\nInsert the VARIABLE data from /etc/os-release. If this file does\nnot exist then fall back to /usr/lib/os-release. If the VARIABLE\nargument is not specified, then use PRETTYNAME from the file or\nthe system name (see \\s). This escape code can be used to keep\n/etc/issue distribution and release independent. Note that\n\\S{ANSICOLOR} is converted to the real terminal escape sequence.\n\nl\nInsert the name of the current tty line.\n\nm\nInsert the architecture identifier of the machine. Same as uname\n-m.\n\nn\nInsert the nodename of the machine, also known as the hostname.\nSame as uname -n.\n\no\nInsert the NIS domainname of the machine. Same as hostname -d.\n\nO\nInsert the DNS domainname of the machine.\n\nr\nInsert the release number of the OS. Same as uname -r.\n\nt\nInsert the current time.\n\nu\nInsert the number of current users logged in.\n\nU\nInsert the string \"1 user\" or \" users\" where is the number\nof current users logged in.\n\nv\nInsert the version of the OS, that is, the build-date and such.\n\nAn example. On my system, the following /etc/issue file:\n\nThis is \\n.\\o (\\s \\m \\r) \\t\n\ndisplays as:\n\nThis is thingol.orcan.dk (Linux i386 1.1.9) 18:29:30\n", "subsections": [] }, "FILES": { "content": "/var/run/utmp\nthe system status file.\n\n/etc/issue\nprinted before the login prompt.\n\n/etc/os-release /usr/lib/os-release\noperating system identification data.\n\n/dev/console\nproblem reports (if syslog(3) is not used).\n\n/etc/inittab\ninit(8) configuration file for SysV-style init daemon.\n", "subsections": [] }, "BUGS": { "content": "The baud-rate detection feature (the --extract-baud option) requires\nthat agetty be scheduled soon enough after completion of a dial-in call\n(within 30 ms with modems that talk at 2400 baud). For robustness,\nalways use the --extract-baud option in combination with a multiple\nbaud rate command-line argument, so that BREAK processing is enabled.\n\nThe text in the /etc/issue file (or other) and the login prompt are\nalways output with 7-bit characters and space parity.\n\nThe baud-rate detection feature (the --extract-baud option) requires\nthat the modem emits its status message after raising the DCD line.\n", "subsections": [] }, "DIAGNOSTICS": { "content": "Depending on how the program was configured, all diagnostics are\nwritten to the console device or reported via the syslog(3) facility.\nError messages are produced if the port argument does not specify a\nterminal device; if there is no utmp entry for the current process\n(System V only); and so on.\n", "subsections": [] }, "AUTHORS": { "content": "Werner Fink , Karel Zak \n\nThe original agetty for serial terminals was written by W.Z. Venema\n and ported to Linux by Peter Orbaek\n.\n", "subsections": [] }, "REPORTING BUGS": { "content": "For bug reports, use the issue tracker at\nhttps://github.com/karelzak/util-linux/issues.\n", "subsections": [] }, "AVAILABILITY": { "content": "The agetty command is part of the util-linux package which can be\ndownloaded from Linux Kernel Archive\n.\n\nutil-linux 2.37.2 2021-06-02 AGETTY(8)", "subsections": [] } } } }