#!/usr/bin/perl

# merge-tab-files
# by Jon Jensen <jon@endpointdev.com>
# 2008-04-11
#
# A tool for merging multiple tab-delimited files.
# Each tab-delimited file's first line is expected to contain the column names.
#
# Usage: merge-tab-files $file1 [$file2 ...]

use strict;
use warnings;
use List::MoreUtils qw( uniq );
#use Data::Dumper;

my %data;
my @all_cols;

for my $file (@ARGV) {
    open my $in, '<', $file or die "Couldn't open file $file: $!\n";
    $_ = <$in>;
    chomp;
    my @cols = split /\t/, $_, -1;
    push @all_cols, @cols;
    while (<$in>) {
        chomp;
        my @row = split /\t/, $_, -1;
        my $key = $row[0];
        # Don't want to clobber duplicate column definitions if the new one is empty
        $data{$key}{$cols[$_]} ||= $row[$_] for 1..$#cols;
    }
    close $in;
}

@all_cols = uniq @all_cols;
print join("\t", @all_cols), "\n";

#print Dumper(\%data);

no warnings 'uninitialized';

for my $key (sort keys %data) {
    print join("\t", $key, map { $data{$key}{$_} } @all_cols[1..$#all_cols]), "\n";
}
