in reply to Splitting a line on just commas

Response: I'd go the Text::CSV route, but this might help get you started 
use strict;

   sub main{
      my $text   = qq{a,b,"hey, you","str1, str2, str3",end};
      print "Input: $text\n\n";

      # Split the delimiters
      my @values = split( /(?:\,|(\".*?\"))/ , $text);
      
      # Remove the created blanks
      @values    = grep{$_ ne ''} @values;
      
      # Output
      foreach (0..$#values){
          print "$_: $values[$_] \n";
      }
   }
   
   main();

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Output: 
Input: a,b,"hey, you","str1, str2, str3",end

0: a
1: b
2: "hey, you"
3: "str1, str2, str3"
4: end

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Thoughts: I haven't really thought why the blanks are being created - if you take away the grep, you'll see what I'm talking about. I still advise using Text::CSV because using this grep method will remove wanted blanks. Therefore, the above code has structural integrity problems.

Example: a,b,,d,e
You probably really want that space holder there if you're going to be inserting this into a database. The grep would remove it because it has a blank string value ("").

Demize

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Re^2: Splitting a line on just commas
by ikegami (Patriarch) on Jun 14, 2010 at 17:39 UTC

    Ouch! Misusing split, which you attempt to fix by filtering out empty strings, which leads to warnings and the removal of empty fields. 

        Thing being separated
        vvvvvvv
/(?:\,|(\".*?\"))/
    ^^
  Separator

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    How are those two things on equal footing?

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[d/l]
[select]
      Response: I was about to say, you might want to remove all the undefined created by the unmatched parens, before removing the blank fields. 
            @values    = grep{defined} @values;
      @values    = grep{$_ ne ''} @values;

      [download]
      or 
            @values    = grep{defined && $_ ne ''} @values;

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      Again, I would not use this method. It's not good to remove blank string values. As for the equal footing, would this be any less equal: /(?:\,)|(\".*?\")/

      Update: I did forget to include the trailing comma after the quotes, but I still wouldn't use it: /\,|(?:(\".*?\")\,)/

      Demize
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[d/l]
[select]
        The point is that there's no point if removing the extra stuff if you extract the fields right in the first place. It's already been shown how to do that.
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