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Commit | Line | Data |
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232dc924 | 1 | .TH AGETTY 8 "May 2011" "util-linux" "System Administration" |
6dbe3af9 KZ |
2 | .SH NAME |
3 | agetty \- alternative Linux getty | |
fd6b7a7f | 4 | |
6dbe3af9 | 5 | .SH SYNOPSIS |
4cfda3dc | 6 | .B agetty |
f49ccec2 BS |
7 | [options] |
8 | .IR port " [" baud_rate "...] [" term ] | |
fd6b7a7f | 9 | |
6dbe3af9 KZ |
10 | .SH DESCRIPTION |
11 | .ad | |
12 | .fi | |
fd6b7a7f | 13 | \fBagetty\fP opens a tty port, prompts for a login name and invokes |
f61a7d1f | 14 | the /bin/login command. It is normally invoked by \fBinit\fP(8). |
6dbe3af9 | 15 | |
fd6b7a7f | 16 | \fBagetty\fP has several \fInon-standard\fP features that are useful |
f61a7d1f | 17 | for hardwired and for dial-in lines: |
12e45a05 | 18 | .IP \(bu |
6dbe3af9 KZ |
19 | Adapts the tty settings to parity bits and to erase, kill, |
20 | end-of-line and uppercase characters when it reads a login name. | |
21 | The program can handle 7-bit characters with even, odd, none or space | |
22 | parity, and 8-bit characters with no parity. The following special | |
5676f365 | 23 | characters are recognized: Control-U (kill); DEL and |
f61a7d1f | 24 | backspace (erase); carriage return and line feed (end of line). |
b06c1ca6 | 25 | See also the \fB\-\-erase\-chars\fP and \fB\-\-kill\-chars\fP options. |
12e45a05 | 26 | .IP \(bu |
6dbe3af9 KZ |
27 | Optionally deduces the baud rate from the CONNECT messages produced by |
28 | Hayes(tm)-compatible modems. | |
12e45a05 | 29 | .IP \(bu |
6dbe3af9 KZ |
30 | Optionally does not hang up when it is given an already opened line |
31 | (useful for call-back applications). | |
12e45a05 | 32 | .IP \(bu |
fd6b7a7f | 33 | Optionally does not display the contents of the \fI/etc/issue\fP file. |
12e45a05 | 34 | .IP \(bu |
fd6b7a7f | 35 | Optionally displays an alternative issue file instead of \fI/etc/issue\fP. |
12e45a05 | 36 | .IP \(bu |
fd6b7a7f | 37 | Optionally does not ask for a login name. |
12e45a05 | 38 | .IP \(bu |
6dbe3af9 KZ |
39 | Optionally invokes a non-standard login program instead of |
40 | \fI/bin/login\fP. | |
12e45a05 | 41 | .IP \(bu |
f61a7d1f | 42 | Optionally turns on hardware flow control |
12e45a05 | 43 | .IP \(bu |
6dbe3af9 KZ |
44 | Optionally forces the line to be local with no need for carrier detect. |
45 | .PP | |
46 | This program does not use the \fI/etc/gettydefs\fP (System V) or | |
47 | \fI/etc/gettytab\fP (SunOS 4) files. | |
48 | .SH ARGUMENTS | |
49 | .na | |
50 | .nf | |
51 | .fi | |
52 | .ad | |
53 | .TP | |
54 | port | |
e85281a8 | 55 | A path name relative to the \fI/dev\fP directory. If a "\-" is |
fd6b7a7f | 56 | specified, \fBagetty\fP assumes that its standard input is |
6dbe3af9 KZ |
57 | already connected to a tty port and that a connection to a |
58 | remote user has already been established. | |
59 | .sp | |
e85281a8 DWF |
60 | Under System V, a "\-" \fIport\fP argument should be preceded |
61 | by a "\-\-". | |
6dbe3af9 KZ |
62 | .TP |
63 | baud_rate,... | |
64 | A comma-separated list of one or more baud rates. Each time | |
fd6b7a7f | 65 | \fBagetty\fP receives a BREAK character it advances through |
6dbe3af9 KZ |
66 | the list, which is treated as if it were circular. |
67 | .sp | |
68 | Baud rates should be specified in descending order, so that the | |
f61a7d1f | 69 | null character (Ctrl\-@) can also be used for baud-rate switching. |
4cfda3dc | 70 | .sp |
914047b4 KZ |
71 | This argument is optional and unnecessary for \fBvirtual terminals\fP. |
72 | .sp | |
73 | The default for \fBserial terminals\fP is keep the current baud rate | |
b06c1ca6 | 74 | (see \fB\-\-keep\-baud\fP) and if unsuccessful then default to '9600'. |
6dbe3af9 KZ |
75 | .TP |
76 | term | |
77 | The value to be used for the TERM environment variable. This overrides | |
78 | whatever init(8) may have set, and is inherited by login and the shell. | |
4cfda3dc | 79 | .sp |
f61a7d1f BS |
80 | The default is 'vt100', or 'linux' for Linux on a virtual terminal, |
81 | or 'hurd' for GNU Hurd on a virtual terminal. | |
6dbe3af9 KZ |
82 | .SH OPTIONS |
83 | .na | |
84 | .nf | |
85 | .fi | |
86 | .ad | |
87 | .TP | |
e9980cf8 SK |
88 | \-8, \-\-8bits |
89 | Assume that the tty is 8-bit clean, hence disable parity detection. | |
90 | .TP | |
eb8e1f9f | 91 | \-a, \-\-autologin \fIusername\fP |
9aeb66dc KZ |
92 | Log the specified user automatically in without asking for a login name and |
93 | password. The \-f \fIusername\fP option is added to the \fB/bin/login\fP | |
b06c1ca6 | 94 | command line by default. The \-\-login\-options option changes this default |
ee312c65 | 95 | behavior and then only \\u is replaced by the \fIusername\fP and no other |
9aeb66dc | 96 | option is added to the login command line. |
eb8e1f9f | 97 | .TP |
e9980cf8 | 98 | \-c, \-\-noreset |
f61a7d1f | 99 | Don't reset terminal cflags (control modes). See \fBtermios\fP(3) for more |
bb1eea0e KZ |
100 | details. |
101 | .TP | |
01095ae3 | 102 | \-E, \-\-remote |
f61a7d1f BS |
103 | If an \fB\-H\fP \fIfakehost\fP option is given, then an \fB\-r\fP |
104 | \fIfakehost\fP option is added to the \fB/bin/login\fP command line. | |
01095ae3 | 105 | .TP |
e85281a8 | 106 | \-f, \-\-issue\-file \fIissue_file\fP |
e9980cf8 SK |
107 | Display the contents of \fIissue_file\fP instead of \fI/etc/issue\fP. |
108 | This allows custom messages to be displayed on different terminals. | |
109 | The \-i option will override this option. | |
6a4c63d9 | 110 | .TP |
e85281a8 | 111 | \-h, \-\-flow\-control |
6dbe3af9 KZ |
112 | Enable hardware (RTS/CTS) flow control. It is left up to the |
113 | application to disable software (XON/XOFF) flow protocol where | |
114 | appropriate. | |
115 | .TP | |
e9980cf8 | 116 | \-H, \-\-host \fIlogin_host\fP |
f61a7d1f | 117 | Write the specified \fIlogin_host\fP into the utmp file. (Normally, |
e9980cf8 SK |
118 | no login host is given, since \fBagetty\fP is used for local hardwired |
119 | connections and consoles. However, this option can be useful for | |
f61a7d1f | 120 | identifying terminal concentrators and the like.) |
e9980cf8 SK |
121 | .TP |
122 | \-i, \-\-noissue | |
fd6b7a7f | 123 | Do not display the contents of \fI/etc/issue\fP (or other) before writing the |
6dbe3af9 KZ |
124 | login prompt. Terminals or communications hardware may become confused |
125 | when receiving lots of text at the wrong baud rate; dial-up scripts | |
126 | may fail if the login prompt is preceded by too much text. | |
127 | .TP | |
e85281a8 | 128 | \-I, \-\-init\-string \fIinitstring\fP |
726f69e2 | 129 | Set an initial string to be sent to the tty or modem before sending |
f61a7d1f | 130 | anything else. This may be used to initialize a modem. Non-printable |
726f69e2 | 131 | characters may be sent by writing their octal code preceded by a |
f61a7d1f BS |
132 | backslash (\\). For example, to send a linefeed character (ASCII 10, |
133 | octal 012), write \\012. | |
0a8dacfe KZ |
134 | .TP |
135 | \-J,\-\-noclear | |
136 | Do not clear the screen before prompting for the login name | |
137 | (the screen is normally cleared). | |
726f69e2 | 138 | .TP |
3fc62fd3 | 139 | \-l, \-\-login\-program \fIlogin_program\fP |
6dbe3af9 KZ |
140 | Invoke the specified \fIlogin_program\fP instead of /bin/login. |
141 | This allows the use of a non-standard login program (for example, | |
142 | one that asks for a dial-up password or that uses a different | |
143 | password file). | |
144 | .TP | |
f61a7d1f BS |
145 | \-L, \-\-local\-line[=\fImode\fP] |
146 | Control the CLOCAL line flag. The optional \fImode\fP argument is 'auto', 'always' or 'never'. | |
147 | If the \fImode\fP argument is omitted, then the default is 'always'. If the | |
148 | \-\-local\-line option is not given at all, then the default is 'auto'. | |
ef264c83 | 149 | |
4b53739c BS |
150 | The \fImode\fP 'always' forces the line to be a local line with no need for carrier detect. |
151 | This can be useful when you have a locally attached terminal where the serial line | |
f61a7d1f | 152 | does not set the carrier-detect signal. |
ef264c83 | 153 | |
4b53739c | 154 | The \fImode\fP 'never' explicitly clears the CLOCAL flag from the line setting and |
f61a7d1f | 155 | the carrier-detect signal is expected on the line. |
ef264c83 | 156 | |
4b53739c | 157 | The \fImode\fP 'auto' (agetty default) does not modify the CLOCAL setting |
f61a7d1f | 158 | and follows the setting enabled by the kernel. |
eb63b9b8 | 159 | .TP |
3fc62fd3 | 160 | \-m, \-\-extract\-baud |
f61a7d1f | 161 | Try to extract the baud rate from the CONNECT status message |
fd6b7a7f | 162 | produced by Hayes(tm)\-compatible modems. These status |
6dbe3af9 | 163 | messages are of the form: "<junk><speed><junk>". |
fd6b7a7f | 164 | \fBagetty\fP assumes that the modem emits its status message at |
6dbe3af9 KZ |
165 | the same speed as specified with (the first) \fIbaud_rate\fP value |
166 | on the command line. | |
167 | .sp | |
f61a7d1f | 168 | Since the \fB\-m\fP feature may fail on heavily-loaded systems, |
6dbe3af9 KZ |
169 | you still should enable BREAK processing by enumerating all |
170 | expected baud rates on the command line. | |
fd6b7a7f | 171 | .TP |
e85281a8 | 172 | \-n, \-\-skip\-login |
fd6b7a7f | 173 | Do not prompt the user for a login name. This can be used in |
f61a7d1f | 174 | connection with the \fB\-l\fP option to invoke a non-standard login process such |
fd6b7a7f | 175 | as a BBS system. Note that with the \-n option, \fBagetty\fR gets no input from |
f61a7d1f | 176 | the user who logs in and therefore won't be able to figure out parity, |
fd6b7a7f KZ |
177 | character size, and newline processing of the connection. It defaults to |
178 | space parity, 7 bit characters, and ASCII CR (13) end-of-line character. | |
179 | Beware that the program that \fBagetty\fR starts (usually /bin/login) | |
180 | is run as root. | |
6dbe3af9 | 181 | .TP |
0a8dacfe KZ |
182 | \-N, \-\-nonewline |
183 | Do not print a newline before writing out /etc/issue. | |
184 | .TP | |
f61a7d1f | 185 | \-o, \-\-login\-options "\fIlogin_options\fP" |
eb8e1f9f | 186 | Options that are passed to the login program. \\u is replaced |
9aeb66dc KZ |
187 | by the login name. The default \fB/bin/login\fP command line |
188 | is "/bin/login -- <username>". | |
189 | ||
190 | Please read the SECURITY NOTICE below if you want to use this. | |
eb8e1f9f | 191 | .TP |
3fc62fd3 | 192 | \-p, \-\-login\-pause |
eb8e1f9f WF |
193 | Wait for any key before dropping to the login prompt. Can be combined |
194 | with \fB\-\-autologin\fP to save memory by lazily spawning shells. | |
195 | .TP | |
f61a7d1f | 196 | \-r, \-\-chroot \fIdirectory\fP |
4b856ee4 KZ |
197 | Change root to the specified directory. |
198 | .TP | |
3aa6b68f | 199 | \-R, \-\-hangup |
f61a7d1f | 200 | Call vhangup() to do a virtual hangup of the specified terminal. |
3aa6b68f | 201 | .TP |
e85281a8 | 202 | \-s, \-\-keep\-baud |
e9980cf8 SK |
203 | Try to keep the existing baud rate. The baud rates from |
204 | the command line are used when agetty receives a BREAK character. | |
205 | .TP | |
206 | \-t, \-\-timeout \fItimeout\fP | |
6dbe3af9 | 207 | Terminate if no user name could be read within \fItimeout\fP |
f61a7d1f | 208 | seconds. This option should probably not be used with hardwired |
6dbe3af9 KZ |
209 | lines. |
210 | .TP | |
e85281a8 | 211 | \-U, \-\-detect\-case |
f61a7d1f BS |
212 | Turn on support for detecting an uppercase-only terminal. This setting |
213 | will detect a login name containing only capitals as indicating an | |
214 | uppercase-only terminal and turn on some upper-to-lower case conversions. | |
215 | Note that this has no support for any Unicode characters. | |
ff3d19bd | 216 | .TP |
e85281a8 | 217 | \-w, \-\-wait\-cr |
fd6b7a7f KZ |
218 | Wait for the user or the modem to send a carriage-return or a |
219 | linefeed character before sending the \fI/etc/issue\fP (or other) file | |
220 | and the login prompt. Very useful in connection with the \-I option. | |
e9980cf8 | 221 | .TP |
36601b23 KZ |
222 | \-\-nohints |
223 | Do not print hints about Num, Caps and Scroll Locks. | |
224 | .TP | |
3fc62fd3 | 225 | \-\-nohostname |
e85281a8 DWF |
226 | By default the hostname will be printed. With this option enabled, |
227 | no hostname at all will be shown. | |
228 | .TP | |
229 | \-\-long\-hostname | |
230 | By default the hostname is only printed until the first dot. With | |
6afe9db4 BS |
231 | this option enabled, the fully qualified hostname by gethostname() |
232 | or (if not found) by getaddrinfo() is shown. | |
e85281a8 | 233 | .TP |
cb872ac9 | 234 | \-\-erase\-chars \fIstring\fP |
6afe9db4 BS |
235 | This option specifies additional characters that should be interpreted as a |
236 | backspace ("ignore the previous character") when the user types the login name. | |
237 | The default additional \'erase\' has been \'#\', but since util-linux 2.23 | |
238 | no additional erase characters are enabled by default. | |
cb872ac9 KZ |
239 | .TP |
240 | \-\-kill\-chars \fIstring\fP | |
6afe9db4 BS |
241 | This option specifies additional characters that should be interpreted as a |
242 | kill ("ignore all previous characters") when the user types the login name. | |
243 | The default additional \'kill\' has been \'@\', but since util-linux 2.23 | |
244 | no additional kill characters are enabled by default. | |
cb872ac9 | 245 | .TP |
0a8dacfe KZ |
246 | \-\-chdir \fIdirectory\fP |
247 | Change directory before the login. | |
248 | .TP | |
249 | \-\-delay \fInumber\fP | |
250 | Sleep seconds before open tty. | |
251 | .TP | |
252 | \-\-nice \fInumber\fP | |
253 | Run login with this priority. | |
254 | .TP | |
6443dd43 SW |
255 | \-\-reload |
256 | Ask all running agetty instances to reload and update their displayed prompts, | |
257 | if the user has not yet commenced logging in. After doing so the command will | |
a55f60a1 | 258 | exit. This feature might be unsupported on systems without Linux |
6443dd43 SW |
259 | .BR inotify (7). |
260 | .TP | |
e9980cf8 | 261 | \-\-version |
6afe9db4 | 262 | Display version information and exit. |
e9980cf8 SK |
263 | .TP |
264 | \-\-help | |
6afe9db4 | 265 | Display help text and exit. |
726f69e2 | 266 | .PP |
6dbe3af9 | 267 | .SH EXAMPLES |
2b6fc908 KZ |
268 | This section shows examples for the process field of an entry in the |
269 | \fI/etc/inittab\fP file. You'll have to prepend appropriate values | |
270 | for the other fields. See \fIinittab(5)\fP for more details. | |
fd6b7a7f | 271 | |
f61a7d1f | 272 | For a hardwired line or a console tty: |
f9da2801 ER |
273 | |
274 | .RS | |
fd6b7a7f | 275 | /sbin/agetty 9600 ttyS1 |
f9da2801 | 276 | .RE |
6dbe3af9 | 277 | |
f61a7d1f | 278 | For a directly connected terminal without proper carrier-detect wiring |
fd6b7a7f | 279 | (try this if your terminal just sleeps instead of giving you a password: |
f61a7d1f | 280 | prompt): |
f9da2801 ER |
281 | |
282 | .RS | |
fd6b7a7f | 283 | /sbin/agetty \-L 9600 ttyS1 vt100 |
f9da2801 | 284 | .RE |
6dbe3af9 | 285 | |
f61a7d1f | 286 | For an old-style dial-in line with a 9600/2400/1200 baud modem: |
f9da2801 ER |
287 | |
288 | .RS | |
fd6b7a7f | 289 | /sbin/agetty \-mt60 ttyS1 9600,2400,1200 |
f9da2801 | 290 | .RE |
6dbe3af9 | 291 | |
f61a7d1f | 292 | For a Hayes modem with a fixed 115200 bps interface to the machine |
fd6b7a7f KZ |
293 | (the example init string turns off modem echo and result codes, makes |
294 | modem/computer DCD track modem/modem DCD, makes a DTR drop cause a | |
f61a7d1f | 295 | disconnection, and turns on auto-answer after 1 ring): |
f9da2801 ER |
296 | |
297 | .RS | |
fd6b7a7f | 298 | /sbin/agetty \-w \-I 'ATE0Q1&D2&C1S0=1\\015' 115200 ttyS1 |
f9da2801 | 299 | .RE |
6dbe3af9 | 300 | |
eb8e1f9f | 301 | .SH SECURITY NOTICE |
3fc62fd3 KZ |
302 | If you use the \fB\-\-login\-program\fP and \fB\-\-login\-options\fP options, |
303 | be aware that a malicious user may try to enter lognames with embedded options, | |
304 | which then get passed to the used login program. Agetty does check | |
e85281a8 | 305 | for a leading "\-" and makes sure the logname gets passed as one parameter |
eb8e1f9f WF |
306 | (so embedded spaces will not create yet another parameter), but depending |
307 | on how the login binary parses the command line that might not be sufficient. | |
3fc62fd3 | 308 | Check that the used login program can not be abused this way. |
eb8e1f9f | 309 | .PP |
e85281a8 DWF |
310 | Some programs use "\-\-" to indicate that the rest of the commandline should |
311 | not be interpreted as options. Use this feature if available by passing "\-\-" | |
312 | before the username gets passed by \\u. | |
eb8e1f9f | 313 | |
6dbe3af9 | 314 | .SH ISSUE ESCAPES |
f61a7d1f BS |
315 | The issue-file (\fI/etc/issue\fP or the file set with the \fB\-f\fP option) |
316 | may contain certain escape codes to display the system name, date, time | |
317 | etcetera. All escape codes consist of a backslash (\\) immediately | |
fd6b7a7f | 318 | followed by one of the letters explained below. |
6dbe3af9 | 319 | |
2b945eda KZ |
320 | .TP |
321 | 4 or 4{interface} | |
0f283438 KZ |
322 | Insert the IPv4 address the specified network interface (e.g. \\4{eth0}) |
323 | and if the interface argument is not specified then select the first fully | |
324 | configured (UP, non-LOCALBACK, RUNNING) interface. If not found any | |
325 | configured interface fall back to IP address of the machine hostname. | |
2b945eda KZ |
326 | .TP |
327 | 6 or 6{interface} | |
0f283438 | 328 | The same as \\4 but for IPv6. |
6dbe3af9 KZ |
329 | .TP |
330 | b | |
331 | Insert the baudrate of the current line. | |
332 | .TP | |
333 | d | |
334 | Insert the current date. | |
335 | .TP | |
d689166b KZ |
336 | e or e{name} |
337 | Translate the human readable \fIname\fP to esc sequence and insert the sequence | |
338 | (e.g. \\e{red}Alert text.\\e{reset}). If the name argument is not specified then | |
339 | insert \\033. The currently supported names are: black, blink, blue, bold, brown, cyan, | |
340 | darkgray, gray, green, halfbright, lightblue, lightcyan, lightgray, lightgreen, | |
341 | lightmagenta, lightred, magenta, red, reset, reverse, and yellow. All unknown | |
342 | names are silently ignored. | |
583627ef | 343 | .TP |
6dbe3af9 | 344 | s |
e85281a8 | 345 | Insert the system name, the name of the operating system. Same as `uname \-s'. |
b34f097e KZ |
346 | See also \\S escape code. |
347 | .TP | |
348 | S or S{VARIABLE} | |
b28842ae KZ |
349 | Insert the VARIABLE data from \fI/etc/os-release\fP, if the file does not exist |
350 | then fallback to \fI/usr/lib/os-release\fP. If the VARIABLE argument is not | |
351 | specified then use PRETTY_NAME from the file or the system name (see \\s). | |
b34f097e KZ |
352 | This escape code allows to keep \fI/etc/issue\fP distribution and release |
353 | independent. Note that \\S{ANSI_COLOR} is converted to the real terminal | |
354 | escape sequence. | |
6dbe3af9 KZ |
355 | .TP |
356 | l | |
357 | Insert the name of the current tty line. | |
358 | .TP | |
359 | m | |
e85281a8 | 360 | Insert the architecture identifier of the machine. Same as `uname \-m'. |
6dbe3af9 KZ |
361 | .TP |
362 | n | |
e85281a8 | 363 | Insert the nodename of the machine, also known as the hostname. Same as `uname \-n'. |
6dbe3af9 KZ |
364 | .TP |
365 | o | |
e85281a8 | 366 | Insert the NIS domainname of the machine. Same as `hostname \-d'. |
e61e66bd KZ |
367 | .TP |
368 | O | |
369 | Insert the DNS domainname of the machine. | |
6dbe3af9 KZ |
370 | .TP |
371 | r | |
e85281a8 | 372 | Insert the release number of the OS. Same as `uname \-r'. |
6dbe3af9 KZ |
373 | .TP |
374 | t | |
375 | Insert the current time. | |
376 | .TP | |
377 | u | |
378 | Insert the number of current users logged in. | |
379 | .TP | |
380 | U | |
381 | Insert the string "1 user" or "<n> users" where <n> is the number of current | |
382 | users logged in. | |
f61a7d1f | 383 | .TP |
6dbe3af9 KZ |
384 | v |
385 | Insert the version of the OS, eg. the build-date etc. | |
e438668b | 386 | .PP |
6dbe3af9 | 387 | Example: On my system, the following \fI/etc/issue\fP file: |
e438668b | 388 | .sp |
6dbe3af9 | 389 | .na |
e438668b | 390 | .RS |
6dbe3af9 | 391 | .nf |
6dbe3af9 | 392 | This is \\n.\\o (\\s \\m \\r) \\t |
e438668b ER |
393 | .fi |
394 | .RE | |
395 | .PP | |
f61a7d1f | 396 | displays as: |
e438668b ER |
397 | .sp |
398 | .RS | |
399 | .nf | |
6dbe3af9 | 400 | This is thingol.orcan.dk (Linux i386 1.1.9) 18:29:30 |
6dbe3af9 | 401 | .fi |
e438668b | 402 | .RE |
6dbe3af9 KZ |
403 | |
404 | .SH FILES | |
405 | .na | |
48cb48dc ER |
406 | .TP |
407 | .B /var/run/utmp | |
408 | the system status file. | |
409 | .TP | |
410 | .B /etc/issue | |
411 | printed before the login prompt. | |
412 | .TP | |
b28842ae | 413 | .B /etc/os-release /usr/lib/os-release |
b34f097e KZ |
414 | operating system identification data. |
415 | .TP | |
48cb48dc ER |
416 | .B /dev/console |
417 | problem reports (if syslog(3) is not used). | |
418 | .TP | |
419 | .B /etc/inittab | |
b34f097e | 420 | \fIinit\fP(8) configuration file for SysV-style init daemon. |
6dbe3af9 KZ |
421 | .SH BUGS |
422 | .ad | |
423 | .fi | |
f61a7d1f | 424 | The baud-rate detection feature (the \fB\-m\fP option) requires that |
fd6b7a7f | 425 | \fBagetty\fP be scheduled soon enough after completion of a dial-in |
6dbe3af9 | 426 | call (within 30 ms with modems that talk at 2400 baud). For robustness, |
f61a7d1f | 427 | always use the \fB\-m\fP option in combination with a multiple baud |
6dbe3af9 KZ |
428 | rate command-line argument, so that BREAK processing is enabled. |
429 | ||
fd6b7a7f | 430 | The text in the \fI/etc/issue\fP file (or other) and the login prompt |
6dbe3af9 KZ |
431 | are always output with 7-bit characters and space parity. |
432 | ||
f61a7d1f | 433 | The baud-rate detection feature (the \fB\-m\fP option) requires that |
6dbe3af9 KZ |
434 | the modem emits its status message \fIafter\fP raising the DCD line. |
435 | .SH DIAGNOSTICS | |
436 | .ad | |
437 | .fi | |
438 | Depending on how the program was configured, all diagnostics are | |
439 | written to the console device or reported via the syslog(3) facility. | |
440 | Error messages are produced if the \fIport\fP argument does not | |
726f69e2 | 441 | specify a terminal device; if there is no utmp entry for the |
6dbe3af9 | 442 | current process (System V only); and so on. |
4cfda3dc KZ |
443 | .SH AUTHORS |
444 | .UR werner@suse.de | |
445 | Werner Fink | |
446 | .UE | |
447 | .br | |
448 | .UR kzak@redhat.com | |
449 | Karel Zak | |
450 | .UE | |
451 | .sp | |
452 | The original | |
453 | .B agetty | |
454 | for serial terminals was written by W.Z. Venema <wietse@wzv.win.tue.nl> | |
455 | and ported to Linux by Peter Orbaek <poe@daimi.aau.dk>. | |
6dbe3af9 | 456 | |
86d62711 | 457 | .SH AVAILABILITY |
601d12fb | 458 | The agetty command is part of the util-linux package and is available from |
e85281a8 | 459 | ftp://ftp.kernel.org/pub/linux/utils/util\-linux/. |