Hi, Try this.... it is quite helpful to you. here is the code....
open( ABB, '<', 'jabb.txt' ) or die "Couldn't open ABB.\n$!"; open( IN, '<', 'input.txt' ) or die "Couldn't open infile.\n$!"; open( OUT, '>', 'output.out' ) or die "Couldn't open outfile.\n$!"; my @myin = <IN>; while(<ABB>) { ($abb,$full) = split/\t/,$_; chomp($abb); chomp($full); for ($t=0;$t<=$#myin;$t++) { $myin[$t] =~s/$full/$abb/g; } } print OUT "@myin\n";