|
Red Hat Linux 6.0 achieves these goals through the use of two programs,
initlog and minilogd, plus a lot of shell scripting around them.
initlog
initlog is a logging program similar to
logger. It is used to log
various items to the system syslog daemon, whatever that might be.
It can be operated in multiple ways:
- If passed a command line with the -c parameter, initlog will execute the specified command, logging anything output of that command;
- If passed a string with the -s option, initlog will log that string to the system logger;
- If passed an event with the -e parameter, initlog will log that a particular event occured.
- Currently specified events include:
- a command completed successfully;
- a command failed;
- a command was canceled at the users request;
- a command failed due to the failure of a dependent action.
- If passed a command line with the -r parameter, initlog will execute the specified command, leaving a pipe open to the command on which it can pass back further commands to initlog.
When it recieves data to log, initlog goes through a simple heiruistic
to determine what to do with the data.
- Check for the existence of /dev/log. If so, log the data via the C library's syslog() routine.
- Attempt to start a mini-syslog daemon, minilogd. If successful, log via syslog().
- Store the data in a local buffer, and try again when more data is recieved.
minilogd
minilogd is a simple syslog daemon. It listens on the local socket
/dev/log, and collects data received by standard system log
mechanisms. It stores the data in a local buffer.
If another log daemon, such as syslogd, starts,
it will remove the /dev/log socket from minilogd,
and create one of its own. When this happens, minilogd will flush its
data to the new daemon, and exit.
|
