The default issue file is /etc/issue. If the file exists, then
agetty also checks for /etc/issue.d directory. The directory is
optional extension to the default issue file and content of the
directory is printed after /etc/issue content. If the /etc/issue
does not exist, then the directory is ignored. All files with
.issue extension from the directory are printed in version-sort
order. The directory can be used to maintain 3rd-party messages
independently on the primary system /etc/issue file.
Since version 2.35 additional locations for issue file and
directory are supported. If the default /etc/issue does not
exist, then agetty checks for /run/issue and /run/issue.d,
thereafter for /usr/lib/issue and /usr/lib/issue.d. The directory
/etc is expected for host specific configuration, /run is
expected for generated stuff and /usr/lib for static distribution
maintained configuration.
The default path maybe overridden by --issue-file option. In this
case specified path has to be file or directory and all the
default issue file and directory locations are ignored.
The issue file feature can be completely disabled by --noissue
option.
It is possible to review the current issue file by agetty
--show-issue on the current terminal.
The issue files may contain certain escape codes to display the
system name, date, time et cetera. All escape codes consist of a
backslash (\) immediately followed by one of the characters
listed below.
4 or 4{interface}
Insert the IPv4 address of the specified network interface
(for example: \4{eth0}). If the interface argument is not
specified, then select the first fully configured (UP,
non-LOCALBACK, RUNNING) interface. If not any configured
interface is found, fall back to the IP address of the
machine's hostname.
6 or 6{interface}
The same as \4 but for IPv6.
b
Insert the baudrate of the current line.
d
Insert the current date.
e or e{name}
Translate the human-readable name to an escape sequence and
insert it (for example: \e{red}Alert text.\e{reset}). If the
name argument is not specified, then insert \033. The
currently supported names are: black, blink, blue, bold,
brown, cyan, darkgray, gray, green, halfbright, lightblue,
lightcyan, lightgray, lightgreen, lightmagenta, lightred,
magenta, red, reset, reverse, yellow and white. All unknown
names are silently ignored.
s
Insert the system name (the name of the operating system).
Same as 'uname -s'. See also the \S escape code.
S or S{VARIABLE}
Insert the VARIABLE data from /etc/os-release. If this file
does not exist then fall back to /usr/lib/os-release. If the
VARIABLE argument is not specified, then use PRETTY_NAME from
the file or the system name (see \s). This escape code can be
used to keep /etc/issue distribution and release independent.
Note that \S{ANSI_COLOR} is converted to the real terminal
escape sequence.
l
Insert the name of the current tty line.
m
Insert the architecture identifier of the machine. Same as
uname -m.
n
Insert the nodename of the machine, also known as the
hostname. Same as uname -n.
o
Insert the NIS domainname of the machine. Same as hostname
-d.
O
Insert the DNS domainname of the machine.
r
Insert the release number of the OS. Same as uname -r.
t
Insert the current time.
u
Insert the number of current users logged in.
U
Insert the string "1 user" or "<n> users" where <n> is the
number of current users logged in.
v
Insert the version of the OS, that is, the build-date and
such.
An example. On my system, the following /etc/issue file:
This is \n.\o (\s \m \r) \t
displays as:
This is thingol.orcan.dk (Linux i386 1.1.9) 18:29:30
