doing in perl ----> ps -ef

matt007 · 09-30-2009, 12:32 PM

i need to grep the output of the ps command and this is what i have to do

So if this returns a non-null result set, i continue processing otherwise exit or break from loop...

ps -ef | grep "/bin/sh /opt"

what would the syntax for perl be...

mmrtnt · 09-30-2009, 01:35 PM

if( `ps -ef | grep "/bin/sh /opt"` )
{
print "Found the proc\n";
}
else
{
print "Proc not found\n";
}

-- or --

if( `ps -ef | grep -c "/bin/sh /opt"` > 0 )
{...}
else
{...}

-- or --

$test = `ps -ef | grep "/bin/sh /opt"`;
if( defined( $test ) )
{...}
else
{...}

Have you looked at pgrep?

Prehistorik · 09-30-2009, 02:07 PM

Do you want to replace the command with Perl script completely?
Or do you just want to get rid of grep?

A script for the second case:

Code:

#!/usr/bin/perl
use strict;

my $CMD = '/bin/sh /opt';
my $C = qr/$CMD/;

my $run = 1;
while($run) {
  open I, "ps -ef |" || die "Cannot open pipe";
  $_ = <I>;
  last unless scalar (grep { /$C/ } map { /^(?:\S+\s+){7}(.*)$/; $1 } <I>);
  print localtime(time) . ": Still running...\n";
  close I;
}

(UPDATE)
...but the script above by mmrtnt does the same in a much simpler way...

chrism01 · 10-02-2009, 01:36 AM

And in the Perl spirit of TMTOWTDI

http://perldoc.perl.org/IPC/Open2.html
http://perldoc.perl.org/IPC/Open3.html
http://perldoc.perl.org/perlipc.html...%28%29-for-IPC
and even
http://search.cpan.org/~durist/Proc-...ess/Process.pm (see also http://search.cpan.org/~durist/Proc-...rocessTable.pm)