logd

SYNOPSIS
       logd [OPTION]...

DESCRIPTION
       logd  is  started by init(8) to receive the output of jobs with console
       logged in their job definition, which is the default if no  other  con-
       sole setting is given.

       Output  is timestamped and written, with the job name, to /var/log/boot
       or stored in memory until the file is writable.

OPTIONS
       --daemon
              Detaches from the terminal and runs in the background.

STARTUP
       To eliminate race conditions on startup, such as  not  being  ready  to
       receive connections when the first job is started, the following proce-
       dure is used.

       Once ready to receive connections,  logd  raises  the  SIGSTOP  signal,
       putting itself to sleep until continued by another process.

       After starting logd, init(8) waits for the process to stop if it hasn't
       already, and then sends it the SIGCONT signal so that it  can  proceed.
       Only once this has happened, will init(8) start other jobs.

       When  the --daemon option is given, this is not performed; instead logd
       will not detach from the console until it is listening on the socket.

SOCKET PROTOCOL
       logd listens on a unix(7) stream  socket  in  the  abstract  namespace,
       bound to /com/ubuntu/upstart/logd.

       init(8) opens a new connection for each job that is to be logged, bind-
       ing the socket to the standard input, output and error file descriptors
       for the job.

       Before  running the job, it sends the job name on the socket so that it
       can be logged along with the messages.  This is sent as a  size_t  that
       contains  the length of the name to read, followed by that many charac-
       ter bytes.  The NULL terminator is not sent as part of the protocol, it
       is up to the receiver to add that if required.

       Further  information  about  the  job,  such as its description, can be
       obtained by opening an ordinary connection to the  init(8)  daemon  and
       querying it using the name received.

AUTHOR
       Written by Scott James Remnant.

REPORTING BUGS
       Report bugs at https://launchpad.net/products/upstart/+bugs

Upstart                          October 2006                          logd(8)