#!usr/bin/perl -w
use strict;

my $line = "value3,value7, value1 ,value5";

#to show what the split does...
print split(/[, ]/,$line),"\n";

if (grep {/^value1$/} split(/[, ]/,$line) )
{
   print "value1 found!\n";
}
#prints: 
#value3value7value1value5
#value1 found!