my $cmd = "egrep -f $_proj_file $_running_file > $_admin_temp_file";
print $cmd, "\n";
my $result = system $cmd;
print "result of egrep = $result\n"
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The quotes shouldn't interfere and would be required if he had spaces in his filenames for example

Confucius says kill mosquito unless cannon

It sometimes makes the code more readable to delimit strings in qq{}:

my $cmd = qq{ egrep -f "$_proj_file" "$_running_file" > "$_admin_temp_
+file" };
my $result = `$cmd`; # or even qx{$cmd}
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That keeps you from having to escape quotes, etc.

I sense with a pattern with your questions... Don't ask Perl what the error is, surely a monk can sense it.

Does egrep produce an error message? If so, what is it?

What is the exit status of the failing egrep command?

What happens if you do the following within perl?

`egrep -f temp_qc_file.txt temp_qc_running_file.txt > temp_file.txt`;
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If the problem is still there, than check paths. Do you run you perl script from the same location as unix command?

`egrep -f "$_proj_file" "$_running_file" > "$_admin_temp_file"`;
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Of course the question is why you use `...` instead of system(...), if you are not interested in the output of the egrep, but maybe egrep is writing something to stderr, and the way you code it, that stderr gets lost. I suggest you try

my $errmsg=`egrep -f "$_proj_file" "$_running_file" > "$_admin_temp_fi
+le"`;
print "egrep error: $errmsg\n" if $errmsg;
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#!/usr/bin/perl
my $ouput = `egrep -f patternfile testfile > output`;
print "$output\n";
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The following also works

#!/usr/bin/perl
my $p = 'patternfile';
my $t = 'testfile';
my $o = 'output';

my $ouput = `egrep -f $p $t > $o`;
print "$output\n";
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