in reply to Regex to match multiple words in an email subject

#!/usr/bin/perl

use warnings;
use strict;

for (<DATA>) {
    print /(?:SSL|SSL Certificate|VASCO)/ ? "Match\n" : "No match\n";
}


__DATA__
SSL
SSL Certificate
VASCO
something else

[download]

Output:

Match
Match
Match
No match

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Re^2: Regex to match multiple words in an email subject
by jwkrahn (Abbot) on Jan 07, 2011 at 07:22 UTC 
        print /(?:SSL|SSL Certificate|VASCO)/ ? "Match\n" : "No match\n";

    [download]

    Because the pattern is not anchored at either end the string 'SSL Certificate' will never match. 

    $ perl -le'
my @strings = (
    "SSL",
    "SSL Certificate",
    "VASCO",
    "something else",
    );
for ( @strings ) {
    print $1 if /(SSL|SSL Certificate|VASCO)/;
    }
'
SSL
SSL
VASCO

    [download]

    With no anchors you need to put the longer strings first: 

    $ perl -le'
my @strings = (
    "SSL",
    "SSL Certificate",
    "VASCO",
    "something else",
    );
for ( @strings ) {
    print $1 if /(SSL Certificate|SSL|VASCO)/;
    }
'
SSL
SSL Certificate
VASCO

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      That's a good point, but in the OP's use case it's irrelevant. In fact, the regex could be trimmed down to:

      /(SSL|VASCO)/

      Or, to avoid unnecessary capturing:

      /(?:SSL|VASCO)/
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