Batch renaming

Batch renaming is the process of renaming multiple computer files and folders in an automated fashion, to save time and reduce the amount of work involved. Some sort of software is required to do this. Such software can be more or less advanced, but most have the same basic functions. Batch renaming software exists for most operating systems.

Batch renaming can also be referred to as 'mass file renaming', rename 'en masse' and 'bulk renaming'.

Common functions

Most batch renamers share a basic set of functions to manipulate the filenames:

* Find a string within the filename and replace it with another, or remove it.

* Setting the capitalization of the letters in the filenames.

* Extracting information from the files, such as Mp3 ID3 tags, and putting it in the filename.

* Add a number sequence (001,002,003,...) to a list of files.

Some batch rename software can do more than just renaming filenames. Features include changing the dates of files and changing the file attributes (such as the write protected attribute).

Common uses

There are many situations where batch renaming software can be useful. Here is a list of some common uses:

* Many digital cameras store images using a base filename, such as DCSN0001 or IMG0001. Using a batch renamer the photographer can easiliy give the pictures meaningful names.

* When downloading files from the Internet such as mp3 music, the files often have crude names. A batch renamer can be used to quickly change the filenames to a style that suits the person who downloaded them.

* When managing large amount of files, such as a picture database, a batch renamer is more or less essential for the task of maintaining filenames without too much manual labour.

Basic renaming problems

There is some problem to take in consideration when renaming a file list.
(=> means: renamed to)

* Detect that the target filename doesn't already exist.

file01 => file02 (file02 already exists in file-system)

* Detect that the target filename is not already used.

file01 => file03
file02 => file03 (file03 is already used)

* Detect cycle renaming (Solved by a two-pass renaming).

file01 => file02 (file02 already exists in file-system)
file02 => file03 (file03 already exists in file-system)
file03 => file01 (file01 already exists in file-system)

Two-pass renaming

A two-pass renaming use a temporary filename (that doesn't exist in file-system) as shown below.
(=> means: renamed to)

* First pass

file01 => file01_AAAAA
file02 => file02_AAAAB
file03 => file03_AAAAC

* Second pass

file01_AAAAA => file02
file02_AAAAB => file03
file03_AAAAC => file01

It solves the cycle renaming problem.

List of batch renaming software

For Mac OS X :
* Automator, - comes with Mac OS X

For Linux :
* GNOME Commander - open source
* GPRename - open source

Cross-platform :
* Métamorphose - open source