making arrays from tab-delimited text file column

Posted by absolutenewbie on Stack Overflow See other posts from Stack Overflow or by absolutenewbie
Published on 2012-04-14T14:40:20Z Indexed on 2012/04/14 23:29 UTC
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I was wondering if anyone could help a desperate newbie with perl with the following question. I've been trying all day but with my perl book at work, I can't seem to anything relevant in google...or maybe am genuinely stupid with this.

I have a file that looks something like the following:

Bob     April
Bob     April
Bob     March
Mary    August
Robin   December
Robin   April

The output file I'm after is:

Bob     April April March
Mary    August
Robin   December April

So that it lists each month in the order that it appears for each person.

I tried making it into a hash but of course it wouldn't let me have duplicates so I thought I would like to have arrays for each name (in this example, Bob, Mary and Robin). I'm afraid to upload the code I've been trying to tweak because I know it'll be horribly wrong. I think I need to define(?) the array. Would this be correct?

Any help would be greatly appreciated and I promise I will be studying more about perl in the meantime.

Thank you for your time, patience and help.

#!/usr/bin/perl -w

while (<>) {
    chomp;
    if (defined $old_name) {
        $name=$1;
        $month=$2;
        if ($name eq $old_name) { 
            $array{$month}++;   
            }
        else { 
            print "$old_name";
            foreach (@array)  { 
                push (@array, $month);
                print "\t@array";
                }
            print "\n";
            @array=(); 
            $array{$month}++; 
            }
        }
    else { 
        $name=$1;
        $month=$2;
        $array{month}++;
        }
    $old_name=$name; 
    }
print "$old_name"; 
foreach (@array)  {
    push (@array, $month);
    print "\t@array";
    }
print "\n";

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