From 6dbe3af945a63f025561abb83275cee9ff06c57b Mon Sep 17 00:00:00 2001 From: Karel Zak Date: Thu, 7 Dec 2006 00:25:32 +0100 Subject: Imported from util-linux-2.2 tarball. --- login-utils/agetty.8 | 241 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 241 insertions(+) create mode 100644 login-utils/agetty.8 (limited to 'login-utils/agetty.8') diff --git a/login-utils/agetty.8 b/login-utils/agetty.8 new file mode 100644 index 000000000..3f3cf6ada --- /dev/null +++ b/login-utils/agetty.8 @@ -0,0 +1,241 @@ +.TH AGETTY 8 +.ad +.fi +.SH NAME +agetty \- alternative Linux getty +.SH SYNOPSIS +.na +.nf +agetty [-ihL] [-l login_program] [-m] [-t timeout] port baud_rate,... [term] +agetty [-ihL] [-l login_program] [-m] [-t timeout] baud_rate,... port [term] +.SH DESCRIPTION +.ad +.fi +\fIagetty\fP opens a tty port, prompts for a login name and invokes +the /bin/login command. It is normally invoked by \fIinit(8)\fP. + +\fIagetty\fP has several \fInon-standard\fP features that are useful +for hard-wired and for dial-in lines: +.IP o +Adapts the tty settings to parity bits and to erase, kill, +end-of-line and uppercase characters when it reads a login name. +The program can handle 7-bit characters with even, odd, none or space +parity, and 8-bit characters with no parity. The following special +characters are recognized: @ and Control-U (kill); #, DEL and +back space (erase); carriage return and line feed (end of line). +.IP o +Optionally deduces the baud rate from the CONNECT messages produced by +Hayes(tm)-compatible modems. +.IP o +Optionally does not hang up when it is given an already opened line +(useful for call-back applications). +.IP o +Optionally does not display the contents of the \fI/etc/issue\fP file +(System V only). +.IP o +Optionally invokes a non-standard login program instead of +\fI/bin/login\fP. +.IP o +Optionally turns on hard-ware flow control +.IP o +Optionally forces the line to be local with no need for carrier detect. +.PP +This program does not use the \fI/etc/gettydefs\fP (System V) or +\fI/etc/gettytab\fP (SunOS 4) files. +.SH ARGUMENTS +.na +.nf +.fi +.ad +.TP +port +A path name relative to the \fI/dev\fP directory. If a "-" is +specified, \fIagetty\fP assumes that its standard input is +already connected to a tty port and that a connection to a +remote user has already been established. +.sp +Under System V, a "-" \fIport\fP argument should be preceded +by a "--". +.TP +baud_rate,... +A comma-separated list of one or more baud rates. Each time +\fIagetty\fP receives a BREAK character it advances through +the list, which is treated as if it were circular. +.sp +Baud rates should be specified in descending order, so that the +null character (Ctrl-@) can also be used for baud rate switching. +.TP +term +The value to be used for the TERM environment variable. This overrides +whatever init(8) may have set, and is inherited by login and the shell. +.SH OPTIONS +.na +.nf +.fi +.ad +.TP +-h +Enable hardware (RTS/CTS) flow control. It is left up to the +application to disable software (XON/XOFF) flow protocol where +appropriate. +.TP +-i +Do not display the contents of \fI/etc/issue\fP 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. +.TP +-l login_program +Invoke the specified \fIlogin_program\fP instead of /bin/login. +This allows the use of a non-standard login program (for example, +one that asks for a dial-up password or that uses a different +password file). +.TP +-m +Try to extract the baud rate the \fIconnect\fP status message +produced by some Hayes(tm)-compatible modems. These status +messages are of the form: "". +\fIagetty\fP assumes that the modem emits its status message at +the same speed as specified with (the first) \fIbaud_rate\fP value +on the command line. +.sp +Since the \fI-m\fP feature may fail on heavily-loaded systems, +you still should enable BREAK processing by enumerating all +expected baud rates on the command line. +.TP +-t timeout +Terminate if no user name could be read within \fItimeout\fP +seconds. This option should probably not be used with hard-wired +lines. +.TP +-L +Force the line to be local line with no need for carrier detect. This can +be useful when you have locally attached terminal where the serial line +does not set the carrier detect signal. + +.SH EXAMPLES +.na +.nf +This section shows sample entries for the \fI/etc/inittab\fP file. + +For a hard-wired line: +.ti +5 +tty1:con80x60:/sbin/agetty 9600 tty1 + +For a dial-in line with a 9600/2400/1200 baud modem: +.ti +5 +ttyS1:dumb:/sbin/agetty -mt60 ttyS1 9600,2400,1200 + +These examples assume you use the simpleinit(8) init program for Linux. +If you use a SysV like init (does /etc/inittab mention "respawn"?), refer +to the appropriate manual page. + +.SH ISSUE ESCAPES +The \fI/etc/issue\fP file may contain certain escape codes to display the +system name, date and time etc. All escape codes consist of a backslash +(\\) immediately followed by one of the letters explained below. + +.TP +b +Insert the baudrate of the current line. +.TP +d +Insert the current date. +.TP +s +Insert the system name, the name of the operating system. +.TP +l +Insert the name of the current tty line. +.TP +m +Insert the architecture identifier of the machine, eg. i486 +.TP +n +Insert the nodename of the machine, also known as the hostname. +.TP +o +Insert the domainname of the machine. +.TP +r +Insert the release number of the OS, eg. 1.1.9. +.TP +t +Insert the current time. +.TP +u +Insert the number of current users logged in. +.TP +U +Insert the string "1 user" or " users" where is the number of current +users logged in. +.TP +v +Insert the version of the OS, eg. the build-date etc. +.TP +Example: On my system, the following \fI/etc/issue\fP file: + +.na +.nf +.ti +.5 +This is \\n.\\o (\\s \\m \\r) \\t +.TP +displays as + +.ti +.5 +This is thingol.orcan.dk (Linux i386 1.1.9) 18:29:30 + +.fi + +.SH FILES +.na +.nf +/etc/utmp, the system status file (System V only). +/etc/issue, printed before the login prompt (System V only). +/dev/console, problem reports (if syslog(3) is not used). +/etc/inittab (Linux simpleinit(8) configuration file). +.SH BUGS +.ad +.fi +The baud-rate detection feature (the \fI-m\fP option) requires that +\fIagetty\fP be scheduled soon enough after completion of a dial-in +call (within 30 ms with modems that talk at 2400 baud). For robustness, +always use the \fI-m\fP option in combination with a multiple baud +rate command-line argument, so that BREAK processing is enabled. + +The text in the /etc/issue file and the login prompt +are always output with 7-bit characters and space parity. + +The baud-rate detection feature (the \fI-m\fP option) requires that +the modem emits its status message \fIafter\fP raising the DCD line. +.SH DIAGNOSTICS +.ad +.fi +Depending on how the program was configured, all diagnostics are +written to the console device or reported via the syslog(3) facility. +Error messages are produced if the \fIport\fP argument does not +specify a terminal device; if there is no /etc/utmp entry for the +current process (System V only); and so on. +.SH AUTHOR(S) +.na +.nf +W.Z. Venema +Eindhoven University of Technology +Department of Mathematics and Computer Science +Den Dolech 2, P.O. Box 513, 5600 MB Eindhoven, The Netherlands + +Peter Orbaek +Linux port. + +.SH CREATION DATE +.na +.nf +Sat Nov 25 22:51:05 MET 1989 +.SH LAST MODIFICATION +.na +.nf +91/09/01 23:22:00 +.SH VERSION/RELEASE +.na +.nf +1.29 -- cgit v1.2.3-55-g7522