Shell Programming and Scripting

join -o 1.1 1.2 2.2 1.3 2.3 file1 file2 | tr ' ' ':' >> file3

#! /usr/bin/perl -w
sub combine{
	my $sep=shift;
	my $num=$#_+1;
	for ($i=0;$i<=$num-1;$i++){
		open FH,$_[$i] or die "Can not open file";
		while(<FH>){
			my @tmp=split($sep,$_);
			map {tr/\n//d} @tmp;
			for($j=0;$j<$#tmp;$j++){
				@{$hash{$tmp[0]}}->[$j*$num+$i]=$tmp[1+$j];
			}
		}
	}
	return \%hash;	
}
$ref=combine(" ","a.txt","b.txt","c.txt");
%hash=%{$ref};
for $key (keys %hash){
	print $key,":",join ":",@{$hash{$key}};
	print "\n";
}