ON(1): notify the user or run commands when files or user  status
     change
     __________________________________________________

     USAGE

         usage: on [-1Du] file [cmd...]
             -1: terminate after the first change
             -D: debug
             -u: don't use unix out

             file may be 'user', 'idle', 'busy' and 'wakeup'
             to run the command when the user becomes...

     DESCRIPTION

      On watches for file system or user status  changes  and  runs  a
     command  when  such  event  happens.  If  no command is given the
     changed file name, or the new user status,  is  printed.  When  a
     command  is  given,  the  command  is  executed with any '%' sign
     replaced with the name for the  changed  file  or  the  new  user
     status.

     If the file is a directory  it  is  considered  as  changed  when
     either  the  directory  or  its  contents change. But there is no
     recursion to sub-directories.

     When file is idle or busy  the  command  is  run  when  the  user
     becomes  idle  or  ceases  being  idle.  When  file is wakeup the
     command runs when the terminal resumes from sleep. When  file  is
     user the command runs upon any of these events.

     EXAMPLES

     Useful to run when editing sources:

         ; on . Inst -v

     Or perhaps

         ; on . Test -v

     Synchronize replicas when resuming from sleep:

         ; on wakeup zxsync -v

     SOURCE

     +o    /zx/sys/src/clive/cmd/on

     __________________________________________________

      User's manual. Section 1. Copyright © LSUB 2014-2016