in reply to perl regular expressions

If you want to return a binary found/not found, you can just modify your code to use an alternator: 
find_string {
    my ($file, @strings) = @_;
    open my $fh, '<', $file;
    my $re = join "|", map quotemeta, @strings;
    while (<$fh>) {
        return 1 if /$re/;
    }
    die "Unable to find string: $string";
}

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or, if you're not really comfortable with join and map, 
find_string {
    my ($file, @strings) = @_;
    open my $fh, '<', $file;
    while (<$fh>) {
        for my $string (@strings) {
            return 1 if /\Q$string/;
        }
    }
    die "Unable to find string: $string";
}

[download]

As a side note, it's usually good to wrap input in <code> tags as well, since HTML and perlmonks will collude to mangle your offering.

#11929 First ask yourself `How would I do this without a computer?' Then have the computer do it the same way.

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Re^2: perl regular expressions
by iamsachin (Initiate) on Jun 23, 2014 at 23:25 UTC

    Can i find multiple strings with the code that you mentioned. find_string('filename', "testing,link,rd"); I need to search multiple strings in the same function

[reply]
      Rather than calling the code as 
      find_string('filename', "testing,link,rd");

      [download]
      for as I've written it, you'd invoke it with
      find_string('filename', "testing","link","rd");

      [download]
      Alternatively, you could add a split to my proposed solution.

      #11929 First ask yourself `How would I do this without a computer?' Then have the computer do it the same way.

[reply]
[d/l]
[select]

        thanks for the info,I was wondering if i had to use any perl cpan modules for map and join to work.

[reply]
        Thanks for the info.I was wondering if i had to install perl cpan modules for join and map to work?
[reply]
        Hello,The script is not working.I get the following error:

        Global symbol "$string" requires explicit package name at map.pl line 13. Execution of map.pl aborted due to compilation errors. Use of uninitialized value $file in open at map.pl line 8. readline() on closed filehandle $fh at map.pl line 9.

        I see that you have used @string but I see $string in die "Unable to find string: $string"; 

        
use strict;
use warnings;



find_string {
    my ($file, @strings) = @_;
    open my $fh, '<', $file;
    my $re = join "|", map quotemeta, @strings;
    while (<$fh>) {
        return 1 if /$re/;
    }
    die "Unable to find string: $string";
}

find_string('prepos.config', "testing","link","100K");

        [download]
[reply]
[d/l]
        Still not working. Not enough arguments for read near ""Unable to find string: @strings";" Execution of .pl aborted due to compilation errors.
[reply]

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