Anonymous Monk,
In addition to the trailing newline that you need to chomp offered by pbeckingham, you need to be aware that any meta-characters in the regex need to be escaped if they are not intended to be meta-characters. 
my $re = <STDIN>;
chomp $re;
$re = quotemeta $re;
print "it worked" if $foo =~ /$re/;

[download]
Cheers - L~R

In reply to Re: Using a regex pattern from STDIN by Limbic~Region
in thread Using a regex pattern from STDIN by Anonymous Monk

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