#!/usr/bin/perl -i.bak -w

# inplace.pl A short program to edit all the files in a dir inplace

use strict;

my $dir = 'c:/test1';
my @files;

opendir(DIR, $dir) or die "Can't open dir $dir, Perl says $!\n";
while (my $file = readdir DIR) {
    # only push in the files not the dirs - use full path!
    push @files, "$dir/$file" unless -d "$dir/$file";
}
closedir DIR;

# now do an inplace edit. use a bare block and local to limit
# the scope of our changes to the global @ARGV array to just here
{
    local @ARGV = @files;   # set up a temporary @ARGV for in-place edit
    while (<>) {
        s/this/that/;       # modify the file
        print;              # print the modifications
    }
}