persistent process supervision
perpboot(8)             persistent process supervision             perpboot(8)

       perpboot - startup utility for perpd(8) and an associated logger

       perpboot [-hV] [-dx] [ basedir ]

       perpboot  is  a utility for starting and monitoring a perpd(8) instance
       on basedir with an associated logger.  If  basedir  is  not  specified,
       perpboot  will  use the environmental variable PERP_BASE.  If PERP_BASE
       is not set or empty, perpboot will use a compiled-in value for basedir,
       normally /etc/perp.

       Within basedir, perpboot switches into a subdirectory named .boot/.  It
       then forks two child processes to exec ./rc.log and ./rc.perp,  with  a
       pipe connected between their respective stdin and stdout.

       Normally  ./rc.log will be an executable script that execs into a stdin
       logger, such as tinylog(8) or sissylog(8).  Similarly,  ./rc.perp  will
       be  an  executable script that ultimately execs into perpd(8).  See the
       examples section below for sample scripts.

       perpboot sets up its ./rc.log and ./rc.perp  child  processes  with  an
       environment that:

              o   closes all extraneous file descriptors

              o   redirects unused stdin, stdout, and stderr to /dev/null

              o   redirects  the  stdin of ./rc.log to the stdout of ./rc.perp
                  (and vice versa)

              o   redirects the stderr of ./rc.perp to stdout (with the effect
                  that both stdout and stderr of ./rc.perp are captured by the

              o   sets the environmental variable PERP_BASE to the value  used
                  for basedir

       By  default,  perpboot  itself  acts  as lightweight supervisor for the
       ./rc.log and ./rc.perp  child  processes.   If  perpboot  notices  that
       either of these processes has died, it will try to restart them.

       -d     Detach.   Normally  perpboot itself runs in the foreground.  The
              -d option causes perpboot to detach from the controlling  termi-
              nal and run as a background process.  This option is useful when
              starting perpboot from within a BSD-type  boot  script  such  as

       -h     Help.  Print a brief usage message to stderr and exit.

       -V     Version.  Print the version number to stderr and exit.

       -x     Exit.  Normally perpboot stays resident as a system process that
              monitors its ./rc.log and ./rc.perp  child  processes.   The  -x
              option causes perpboot to start ./rc.log and then replace itself
              with the ./rc.perp process.   This  option  is  used  to  reduce
              process  overhead  and/or when you don't feel the need to retain
              perpboot as a supervisor.  As one example, this option might  be
              used  within  an  inittab(5)  specification  configured with the
              action specified as ``respawn''.

       An example ./rc.log script may look like this:

              exec tinylog -k 8 -s 100000 -t ${LOGDIR}

       This script execs into an instance of tinylog(8) maintaining a  rotated
       set  of  log  files in /var/log/perpd with a maximum of 8 keep files, a
       maximum log size of 100000 bytes, and with timestamp prepended entries.

       An example ./rc.perp script