runsvdir starts a runsv(8) process for each subdirectory, or symlink to a directory, in the services directory dir, up to a limit of 1000 subdirectories, and restarts a runsv(8) process if it terminates. runsvdir skips subdirectory names starting with dots. runsv(8) must be in runsvdir’s PATH.
At least every five seconds runsvdir checks whether the time of last modification, the inode, or the device, of the services directory dir has changed. If so, it re-scans the service directory, and if it sees a new subdirectory, or new symlink to a directory, in dir, it starts a new runsv(8) process; if runsvdir sees a subdirectory being removed that was previously there, it sends the corresponding runsv(8) process a TERM signal, stops monitoring this process, and so does not restart the runsv(8) process if it exits.
If the log argument is given to runsvdir, all output to standard error is redirected to this log, which is similar to the daemontools’ readproctitle log. To see the most recent error messages, use a process-listing tool such as ps(1). runsvdir writes a dot to the readproctitle log every 15 minutes so that old error messages expire.
If runsvdir receives a HUP signal, it sends a TERM signal to each runsv(8) process it is monitoring and then exits with 111.
http://smarden.org/runit/