perl process questions

[dabits]

Hi! I created the following perl subroutine to prevent multiple occurrances of the same script from running. <br>I supply a maximum task count due to the subprocesses perl seems to create for things like globs and the actual grep task! <br>I now would like to kill any previous running occurrances of the script. Given the subprocesses perl creates, it there a best way to do this? For example, if&nbsp;&nbsp;I kill the main perl task, will the child processes die gracefully?<br>I know they will become defunct, but will they also be removed from the process table on Solaris? Or do I need to kill all the child processes first? <br>Any and all suggestions are welcome!<br>Thanks <br><br>sub process_ck{<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;my $mcount = $_[0]; # max task count<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;my $parm = $0;<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;chomp(my @procs = qx!ps -aux¦grep '$parm'!);<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;my ($count, $element);<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;foreach (@procs){<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;if (index($_, $parm) ne -1){<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;$count++;<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;}<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;}<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;if ($count &gt; $mcount){<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;die &quot;Task $parm already running!\n&quot;;<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;}<br>}<br>

 

[MikeLacey]

Hi dabits,<br><br>Just running a Perl script doesn't create child processes - so unless you're explicitly calling fork() in your scripts you can just kill the Perl process.<br><br>A common way to make sure you're only running one copy of a process in Unix is to create a lock file - on startup check for the existence of a particular file, '/tmp/myprog.lock' for instance, if it's there your prog is already running. If it's not - create it and write your process ID (that's $$) to the file and close it. <p>Mike<br><a href=mailto:michael.j.lacey@ntlworld.com>michael.j.lacey@ntlworld.com</a><br><a href=

http://www.cargill.com/>

Cargill's Corporate Web Site</a><br>

 

[Guest_imported]

Don't kill your processes if you're using mod-perl!&nbsp;&nbsp;It keeps open a bunch of processes so that it doesn't have to reinitialize the perl interpreter every time, thus making things much faster.&nbsp;&nbsp;Otherwise, Perl generally cleans up after itself.<br><br>Sincerely, <br><br>Tom Anderson<br>CEO, Order amid Chaos, Inc.<br><A HREF="

http://www.oac-design.com"

TARGET="_new">

http://www.oac-design.com</A>