#!/usr/bin/perl -w
#
# replace_in_tree replaces stringx by stringy in files from current directory
# recursiveley and backups the original files to *.bak like
# find . -type f | xargs -n 255 perl -pi.bak -e 's/string x/string y/g'
# does.
#
# Author : Sascha Wuestemann
# License: Artistic GPL
# eMail  : Sascha.Wuestemann@epost.de
 
use strict;
 
sub usage {
print <<EOF;
 
usage:
 
replace_in_tree <to_be_replaced> <replacement> <filematcher>
 
replaces the string "to_be_replaced" with "replacement"
from the current directory downwards the filetree
in files matching filematcher, e.g. "*" or "*.html"
 
example:
 
replace_in_tree "Author: Bill Gates" "Author: Larry Wall" *.html
 
EOF
}
 
sub exec_replace {
open(GUN,"find . -name \"$ARGV[2]\" -type f | xargs -n 255 perl -pi.bak -e 's/$ARGV[0]/$ARGV[1]/g'|")|| die "can't execute shell commands:$!\n";
close(GUN)|| warn "couldn't close shell:$!\n";
}
 
if (not $ARGV[2]) {
     usage;
     exit;
}
else {
     exec_replace
}
exit;