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

Having issues with regex, input file: 
# Title A  2 B

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A and B can vary for any other letter. But each letter is associated with know value. I need to find what letters are presented then add up the values linked to them. Trying:
if ( $_ =~ /^\S\s+\S+\s[\A\b]/)
              {$sum = 2}
elsif ( $_ =~ /^\S\s+\S+\s[\B\b]/)
              {$sum = 2}
# then for next letter

if ( $_ =~ /^\S\s+\S+\s\S\s+[\B\b]/)
               {$sum += 1}

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it works fine in this case, but if i was to change A to B in input, then the sum printed is wrong??

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Re: regex problem
by kutsu (Priest) on Apr 09, 2004 at 19:23 UTC

    If there is always going to spaces between them you might want to look at split

    #an example
($title, $letter1, $num, $letter2) = split(/ /,$_);

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    Update: Fixed grammer error

    "Cogito cogito ergo cogito sum - I think that I think, therefore I think that I am." Ambrose Bierce

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[d/l]
      would this be useful if the input file had multiple entries of the example line, with other infomration embedded? 
      #  TITLE C 4 B
    INFO
    INFO
#  TITLE A 4 B

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[reply]
[d/l]
        Yes it would ... 
        #an example
($title, $letter1, $num, $letter2) = split(/ /,$_) if /^#  TITLE/;

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        Plankton: 1% Evil, 99% Hot Gas.
[reply]
[d/l]

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