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

I have the following code!! 
foreach $line (@fich){
  $i++;
  foreach $comm (@com){
     if(($line eq $comm)||($line=~/$comm/)){
        print"Line $i: $comm";
      }
  }
}

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The problem is that the instruction in the if condition ($line=~/$comm/) gives me an error!!! "Nested quantifiers before HERE mark in regex m//** << HERE"....

The @comm and @fich arrays contain the contents of two distinct files!

Can someone tell me why this code gives me this error!?

Thank you all

Replies are listed 'Best First'.
Re: Regex ERROR!
by broquaint (Abbot) on Jul 15, 2003 at 09:44 UTC
    You'll need to escape the meta-characters in $comm e.g 
    ## note the \Q before $comm
if(($line eq $comm) || ($line =~ /\Q$comm/)){
  print"Line $i: $comm";
}

    [download]
    And it looks like a simple index would be better suited in this situation since you're just testing to see whether $comm is in $line e.g 
    if(($line eq $comm) || (index($line, $comm) > -1)){
  print"Line $i: $comm";
}

    [download]
    See. perlre and quotemeta for more info on escaping regex meta-characters and perldiag for a more detailed explanation of your error.
    HTH

    _________
    broquaint

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Re: Regex ERROR!
by Skeeve (Parson) on Jul 15, 2003 at 09:47 UTC
    have you tried /\Q$comm/ ? I fear it's a problem with the content of $comm.
[reply]
      Thank you Very much!!!
      In did the \Q was the problem!!!

      It might be a stupid question but what does the \Q does in this context??

      Thank you again for your help!!

      Has in my country they said "The one that doesn´t know is like the one that cannot see!!"

[reply]
        from the perlre man page 
            \Q    quote (disable) pattern metacharacters till \E
        look at this code: 
        $comm = '(xyz';
$line = '123(xyz)456';

if ($line =~ /$comm/) {     #error! same as  $line =~ /(xyz/  which ha
+s an unmatched '('
 # do stuff
}
if ($line =~ /\Q$comm/) {   #no error! same as  $line =~ /\(xyz/  -- '
+(' is escaped
 # do stuff
}

        [download]

        --

        flounder

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