Reading and executing RegExp from text file

KLassesen has asked for the wisdom of the Perl Monks concerning the following question:

I'm tracking down a performance problem (likely some bad regexp) and have a file of existing regexps that is used to filter content. I have been away from Perl for too long a time...

So I want to read the file line by line and convert each to a regexp that I will apply against a reference text (32K) and record the time. The key is to identify the worst ones to look for rewriting. My logic to date is:

while (<FILE>) {
   chomp{$_);
   if(length $_ > 1)
{
   $regex =~ $_;
   $_=$sampletext;
   if(/$regex/)
  {

   }
}}

I'm getting uninitialized values in pattern match and suspect that I have a minor error somewhere -- but can't spot it.

Comment on Reading and executing RegExp from text file

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Re: Reading and executing RegExp from text file by JavaFan (Canon) on Oct 28, 2011 at 01:00 UTC
You want `$regex = $_;`. Or rather something like: `while (my $regex = <FILE>) { chomp $regex; if (length($regex) > 1 && $sampletext =~ $regex) { ... } }` [download]	[reply] [d/l] [select]
Re: Reading and executing RegExp from text file by ww (Archbishop) on Oct 28, 2011 at 12:25 UTC
Typo: chomp{$_); ^	[reply]