Do you actually need to generate a grep command or is it okay to actually perform the search with Perl itself?

Also, there is no reason to do cat file | grep pattern, you can just do grep pattern file. There is a small difference if you are searching more than one file, since grep pattern file1 file2 shows the file names on the output, whereas cat file1 file2 | grep pattern does not.

Okay, if you really need to generate a grep command, I would do it like this:

#!perl -w
use strict;

my $starttim = 4;
my $endtime  = 9;

my $pattern = "^(" . 
  join("|", map { sprintf "%02d", $_ } $starttim .. $endtime ) .
  ")";

my $cmd = "grep -e '$pattern' file";
print "cmd = $cmd\n";

[download]
The join function is great when you need to have things between the elements of list. Much easier than coding a loop.

In reply to Re: Generating a grep command at run time by Thelonius
in thread Generating a grep command at run time by chimni

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