Question

I have a text file which was originally a mysql dump of a database table. How do I write a Perl script to extract all the email addresses from this text file?

The problem I am having is that I read in the lines of the document one by one then do a regular expression, however in cases where there are more than one email address on the same line my script seems to fail.

open (FP, '<my-large-file.txt');
  while($line = <FP>)
  {
      #if($line =~ /\s([\S]{1,80}[@]{1}[\S]{2,100})\s/)
      #if($line =~ /([\S]{1,80}[@]{1}[\S]{2,100})\s/)
      #if($line =~ /([\S]{1,80}[@]{1}[\S]{2,100})[,]/)
      {
          push(@emails, $1);
      }
  }
close (FP);

I have been playing with the above code but did not get the desired outcome.

Answer 1

Use the /g modifier to match a regular expression multiple times:

open (FP, '<my-large-file.txt');
while($line = <FP>)
{
  my @matches = /(\S{1,80}@\S{2,100})\s/g;
  push @emails, @matches;
}
close (FP);