Enbar, if you're familiar with Perl & regular expressions, you might want to give this a go:

($origregexp = shift @ARGV) || die <<"HELPMESSAGE";
Usage: rename perlexpr [filenames]

Example: rn.pl "s/(.*?)\\.(.*\$)/\${1}\\q\\.\${2}/" *;
s/FILENA.EXTEN/FILE\\q.EXTEN/

Notes:
\\q acts as a built in incrementer. So if you have series
of files and the goal is to number them, you could use
a Perl expression to pass the arguments in, in a sorted
manner.
HELPMESSAGE

if (!@ARGV) {
@ARGV = <STDIN>;
chomp(@ARGV);
}

$iter = 0;
$regexp = $origregexp;

#Force it to glob each entry
foreach $_ (<@ARGV> )
{
...

Enbar, if you're familiar with Perl & regular expressions, you might want to give this a go:

($origregexp = shift @ARGV) || die <<"HELPMESSAGE";
Usage: rename perlexpr [filenames]

Example: rn.pl "s/(.*?)\\.(.*\$)/\${1}\\q\\.\${2}/" *;
s/FILENA.EXTEN/FILE\\q.EXTEN/

Notes:
\\q acts as a built in incrementer. So if you have series
of files and the goal is to number them, you could use
a Perl expression to pass the arguments in, in a sorted
manner.
HELPMESSAGE

if (!@ARGV) {
@ARGV = <STDIN>;
chomp(@ARGV);
}

$iter = 0;
$regexp = $origregexp;

#Force it to glob each entry
foreach $_ (<@ARGV> )
{
$old_name = $_;
do
{
if(-e $_)
{
$regexp = $origregexp;
}

if($regexp =~ m/\\q/)
{
$regexp =~ s/\\q/$iter/;
$iter++;
}
eval $regexp;
die $@ if $@;
}while( -e $_ );
print "Turning $old_name into $_\n";
rename($old_name, $_) unless $old_name eq $_;
}

exit(0);

It's not as bad as it looks. You can still use the script even if you're not familiar with Perl. Just copy the text out to a file, rename it to something like rename.pl, download a Perl interpreter - I recommend ActivePerl, and then you'll need just need a passing familiarity with regular expressions (really it's not that hard to learn).

Here are some pretty common regular expressions I use with the script.

Say I have three files Program.txt, Program.exe, and Program.MD5. Now I want rename them from Program to AnotherProgram. To do this I'd open a comm...

It's not as bad as it looks. You can still use the script even if you're not familiar with Perl. Just copy the text out to a file, rename it to something like rename.pl, download a Perl interpreter - I recommend ActivePerl, and then you'll need just need a passing familiarity with regular expressions (really it's not that hard to learn).

Here are some pretty common regular expressions I use with the script.

Say I have three files Program.txt, Program.exe, and Program.MD5. Now I want rename them from Program to AnotherProgram. To do this I'd open a command prompt and type:

rn.pl "s/(.*?)\.(.*$)/AnotherProgram\.${2}/" Program.*

Let me break that down. The

"s/"

means do a substitute. A substitute is what it sounds like it turns one string in to another. The part that comes after it

"(.*?)\.(.*$)"

says grab the filename, the period that follows filename, and the extension and save them for later.

Here's how that's accomplished. In regex speak, the parentheses act as a group that can be referenced later in the predicate of the expression. The period

.

says match any character. The

*

says repeat the thing found on the left of the asterik 0 or more times. The

?

(when it follows a *) says match as few things that form the pattern on the left as possible.

So

(.*?)\.

means find as few alpha-numeric character as possible till a PERIOD is encountered. The

\.

simply says treat this like a normal period - taking away it's special meaning. So remember whenever you see the backslash in a regular expression that's all it means, "escape" or take away the default/special meaning.

So lets say the first string the program encounter is:
Program.txt

It uses the pat

Ahem ...

It uses the pattern (.*?)\. and it scans all the way across the string until it sees the period. Then everything to the left of the period is stored away and can be accessed later by referencing ${1}. Meaning ${1} will contain

Program

The dollar sign

$

means match the end of the string.

So the full expression

(.*?)\.(.*$)

simply means match ALL character up till the period in the filename and store them in ${1}. Then after the period store ALL characters up till the end of the string in ${2}. Or in other words, save the filename to ${1} and the extension to ${2}. So the string we were using as an example - Program.txt - will result ...

Ahem ...

It uses the pattern (.*?)\. and it scans all the way across the string until it sees the period. Then everything to the left of the period is stored away and can be accessed later by referencing ${1}. Meaning ${1} will contain

Program

The dollar sign

$

means match the end of the string.

So the full expression

(.*?)\.(.*$)

simply means match ALL character up till the period in the filename and store them in ${1}. Then after the period store ALL characters up till the end of the string in ${2}. Or in other words, save the filename to ${1} and the extension to ${2}. So the string we were using as an example - Program.txt - will result in ${1} containing "Program" and ${2} containing "txt".

The next part of the substitute is dilineated by the

/

. Like I said above, the substitute requires two pieces of information. It needs a pattern to determine if the passed in string has text in it that we want the program to change, and then if it matches the pattern, it uses information from that regular expression to turn it in to something else.

So the expression

/AnotherProgram\.${2}/

merely says "turn ${1}.${2} in to AnotherProgram.${2}".

That may sound complicated, but you'll find in practice you usually just cut and paste the first part:

rn.pl "s/(.*?)\.(.*$)/

Then all you have to do is specify what you want to turn the filename or extension in to.

Hope this helps.