rename many files automatic one time - ddmmyyyy.file to yyyymmdd.file - php

Question

I have 1500 files that are named with an incorrectly dateformat. I would like to rename them. Are there a tool that can do that? Otherwise a piece of php code.
File names are:
ddmmyyyy.xls (e.g. 15012010 for 15.th Jan 2010)
and I would like:
yyyymmdd.xls (e.g. 20100115.xls)
Any clue on how this can be done for 1500 files in one go?
BR. Anders
UPDATE:
Also tried the MP3TAG, that is suggested in one of the answers. It is a free tool and also did the job. It took a while to figure out how to use it. If you wanne try do this:
add xls (or other format) to the list of editable files in configuration
choose folder to load files AND mark files in the pane you want to edit
I clicked the "Convert - Quick" button. It is also possible to save schemaes for future use but I could not figure out how.
after clicking "convert - quick" choose "using regex" (only regex option)
And then you just add the info to process the renaming. In my case:
field: _FILENAME
from: ([0-9]{2})([0-9]{2})([0-9]{4})
to: $3-$2-$1
Now all files named 15012010.xls (ddmmyyyy.xls) will be named 2010-01-15.xls

Answer 1

Here's a start (untested, but you should get the idea).
$files = glob('your/folder/*.xls');
foreach($files as $file) {
preg_match_all('/^(\d{2})(\d{2})(\d{4})\.xls$/', basename($file), $matches);
if ( ! $matches) continue;
$year = $matches[0][3];
$month = $matches[0][2];
$day = $matches[0][1];
$newFilename = $year . $month . $day . '.xls';
rename ( $file, dirname($file) . '/' . $newFilename );
}

Answer 2

If you have a Linux machine with the files... you can use bash to do:
for f in *.xls; do
mv $f "$(echo $f | cut -c4-8)$(echo $f | cut -c3,4)$(echo $f | cut -c1,2).xls"
done

Answer 3

A tool that can perform filename pattern conversion is Mp3tag.
Choose convert and then filename - filename.
I'm sure there's other tools out there too!
(This answer isn't really in the StackOverflow spirit but I think the OP isn't necessarily looking for an automated solution...)

Answer 4

Based on alex function, but this one correctly adds the .xls extension.
foreach (glob('/path/to/your/*.xls') as $file)
{
rename($file, dirname($file) . '/' . substr(basename($file), 4, 4) . substr(basename($file), 2, 2) . substr(basename($file), 0, 2) . '.xls');
}

Answer 5

if you have bash
#!/bin/bash
shopt -s nullglob
for xls in [0-9]*.xls
do
day=${xls:0:2}
mth=${xls:3:2}
yr=${xls:4:4}
echo mv "$xls" "${yr}${mth}${day}.xls"
done
no need external tools.

Answer 6

File names are: ddmmyyyy.xls (e.g.
15012010 for 15.th Jan 2010)
and I would like: yyyymmdd.xls (e.g.
20100115.xls)
Use this script.
# Script RenameYYYYMMDD.txt
var str dir, list, file, newname, dd, mm
lf -r -n "*.xls" $dir > $list
while ($list <> "")
do
lex "1" $list > $file ; stex -p "^/^l[" $file > $newname ; chex "2]" $newname > $dd
chex "2]" $newname > $mm ; sin "^.^l" ($mm+$dd) $newname > null
system rename ("\""+$file+"\"") $newname
done
This script is in biterscripting ( http://www.biterscripting.com ). Test the script first in a test folder.
To test, save the script code in file "C:/Scripts/RenameYYYYMMDD.txt", and enter the following command.
script "C:/Scripts/RenameYYYYMMDD.txt" dir("C:/path/to/test folder")
This command will rename all files ddmmyyyy.xls under directory "C:/path/to/test folder" to yyyymmdd.xls.