This patch allows to use a new \S or \S{VARNAME} sequence in the
/etc/issue file. The sequence prints data from /etc/os-release. The
reason is to keep /etc/issue file distribution and release
independent.
The \S{ANSI_COLOR} is converted to the real terminal escape seq.
For example:
\S
Kernel \r on an \m (\l)
or more complex example:
Welcome to \S{ANSI_COLOR}\S{NAME}0m \S{VERSION}
Report bugs at \S{BUG_REPORT_URL}.
See http://www.freedesktop.org/software/systemd/man/os-release.html
fr more details about /etc/issue.
Based on patch from Bill Nottingham <notting@redhat.com>.
Signed-off-by: Karel Zak <kzak@redhat.com>