#!/usr/bin/perl while ($filename = shift(@ARGV)) { open(RFILE, "< $filename"); open(WFILE, "> $filename.tmp"); while () { if (/Wonx/) { print $_; s/Wonx/WonX/g; print $_; } print WFILE $_; } close(RFILE); close(WFILE); system("mv $filename.tmp $filename"); }