You should post the code you have tried and describe the precise error message you got when you ran it.

For some general solutions to renaming files, see Larry's famous rename script and Unix rename faq (a version of Larry's script is given at the end). It's also discussed in Perl Cookbook, recipe 9.9.

See also rename 0.3 - now with two extra cupholders, my personal big overhaul of that script.

Which reminds me I need to clean up the current, much further developed version and post it sometime…

Makeshifts last the longest.

Update: Err... this is an old node... I got confused by Mass file renaming. It looks like someone posted under this node than started a new thread with the same title. Blah...

I'm not sure TimToady's script (or Aristotle's version which I like and use quite a lot) is the right solution in this case given that the OP claimed he was extracting info from the file itself.

-sauoq
"My two cents aren't worth a dime.";

#!/usr/bin/perl
#usage: zrn 'oldext' 'newext' 'topdir' 
#include the the . for extensions, otherwise anystring will change in 
+the filenames 
#if you want to append .bak to files, use $ for 'oldext' ex: zrn $ .ba
+k . 
#the ext is always applied to the end of the filename 
#to strip extensions: zrn .bak '' . 
use strict;
use File::Find;

my ($in,$out,$path) = @ARGV;
my $timestamp = localtime();
$timestamp =~ s/ /|/g;
if (@ARGV <2){die "Usage zrn 'oldext' 'newext' 'top directory' -> '.' 
+is good 
                   examples: zrn .bak .old .  
                             zrn  \$  .bak  . 
                             zrn  .bak ''  .\n"};
finddepth (\&wanted,$path);

sub wanted {
my $old = $_;
return unless -f; #-d for dir ops or comment out for both 
$_ =~ s/$in$/$out/; #do ops here 
if ($_ eq $old){return};
if (-e $_) {$_ = $_.$timestamp; warn("timestamping $_ to avoid overwri
+ting existing file")};
rename $old, $_ or warn "Cannot rename $old to $_ in $File::Find::dir:
+ $!";
};
[download]

ls | perl -nle 'print $_'

Replacing the print with something useful. I use this all the time to rename files.