Question

Is it possible to invoke a function when a cron process is killed from the command line (via Ctrl+c) or with the kill command?

I have tried register_shutdown_function(), but it doesn’t seem to be invoked when the script is killed, but does get invoked when the script ends normally.

I am trying to log the result to a file and update a database value when a cron instance is killed automatically (ie. has been running too long).

Answer 1

According to a comment in the manual on register_shutdown_function(), this can be done the following way:

When using CLI ( and perhaps command
line without CLI – I didn’t test it)
the shutdown function doesn’t get
called if the process gets a SIGINT or
SIGTERM. only the natural exit of PHP
calls the shutdown function. To
overcome the problem compile the
command line interpreter with
--enable-pcntl and add this code:

 <?php
 declare(ticks = 1); // enable signal handling
 function sigint()  { 
    exit;  
 }  
 pcntl_signal(SIGINT, 'sigint');  
 pcntl_signal(SIGTERM, 'sigint');  
 ?>

This way when the process recieves one
of those signals, it quits normaly,
and the shutdown function gets called. … (abbreviating to save space, read the full text)

If that is too much hassle, I would consider doing the timing out from within PHP by setting a time limit instead. Reaching the limit will throw a fatal error, and the shutdown function should get called normally.