From Linux Man Pages
blogd - boot logging on /dev/console
/sbin/blogd [/dev/realtty]
DESCRIPTION
Without argument blogd determines the real underlying character device of /dev/console. blogd spawns a pty/tty
pair to reconnect the current /dev/console with the slave of the pty/tty pair. During writing information from
this slave to the real character device a ring buffer is used to hold the information for writing it to an exist-
ing logging file.
To fetch the real tty of /dev/console the program showconsole(8) can be used. This has the advantage that blogd
will not hold the real character device of /dev/console as its controlling tty (would hangup any running getty on
that character device).
SIGNALS
blogd knows a few signal to contol its behavior.
SIGQUIT, SIGINT, and SIGTERM
will cause blogd tries to write out the ring buffer and to exit.
SIGIO says blogd that now it is able to write on /var/log/boot.msg which means that the file system is mounted
read/write and the kernel messages are written to that file.
BUGS
blogd needs a mounted /proc and /dev/pts file system and tries to set the controlling tty to stdin if the real
character device of /dev/console is not given. After reading /proc blogd tries to restore the status of the con-
trolling tty to avoid problems with getty processes. This can fail because blogd forks to run in the background
as a daemon.
FILES
/proc/<pid of blogd>/stat
the stat file of the blogd process.
/dev/console
the system console.
/var/log/boot.msg
logging file which is created by klogd(8) or dmesg(8).
RELATED
showconsole(8), syslogd(8), klogd(8), dmesg(8), proc(5).
COPYRIGHT
2000 Werner Fink, 2000 SuSE GmbH Nuernberg, Germany.
CATEGORY