Checking number of instances running

[Rene Scheibe]

....what do you think about checking the number
of scripts (with a specific name) running by:

my $processname = 'script.pl';
my @log = split /\n+/, `ps ax`;
my $count = 0;
foreach (@log)
{
chomp;
if (/$processname/)
{
$count++;
}
}

Or is there a better solution?
I need this to check at startup of the script
if the max. number of instances i want to allow
is already reached and then to exit new
instances right after this test.

Thanks...
....Rene

 

[pete]

...what do you think about checking the number
of scripts (with a specific name) running by:

my $processname = 'script.pl';
my @log = split /\n+/, `ps ax`;
my $count = 0;
foreach (@log)
{
chomp;
if (/$processname/)
{
$count++;
}
}

Or is there a better solution?
I need this to check at startup of the script
if the max. number of instances i want to allow
is already reached and then to exit new
instances right after this test.

Thanks...
...Rene

You could do

my $processname = "script.pl";
$instances = `ps aux|grep $processname`;
exit if $instances;

That might be slightly faster

Pete

 

[Eric Schwartz]

this exits even if no instance of the script
is running because "ps aux|grep script.pl"
itself is shown as process. and using awk
will slow down things i think.

$instances = `ps aux | grep $processname | grep -v grep | wc -l`
exit if $instances > $limit;

-=Eric