Reference number: CH000428

Changing a file extension.

Issue:

Changing a file extension.

Cause:

It may be necessary to change the file extension to open the file or files with a different application or in a different method.

Solution:

It is important to realize that while you may be able to rename a file, it may or may not be able to be opened in the application used to open the new file extension. A good example would be renaming a batch file (.BAT) to a .EXE. Because a .EXE file needs to be compiled, you will now receive an error when attempting to open the file.

Below is a listing of how to change the file extension for each of the major IBM compatible operating systems:

MS-DOS users

Additional information about how to get into MS-DOS can be found on document CHDOS.

Change the directory to the location of where the file is located. In our below example we will rename the file myfile.txt to myfile.doc.

move myfile.txt myfile.doc

Unless the file already exists you should receive an [ok] message indicating that the file has been renamed.

Additional help and information about move can be found on our move page.

Renaming multiple file extensions

If you wish to rename multiple files that have the same file extension without the aid of a different program we recommend you follow the below steps.

The below example will rename all the files in the current directory that end with .txt to .old.

ren *.txt *.old

See our ren or rename page for additional information about this command.

Windows users

Before renaming a Windows file extension you must have set Windows to display file extensions. By default this option is disabled. Additional information and help with viewing the file extensions can be found on document CH000573.

Using the same examples as we did earlier, assuming the file is named myfile.txt, we will rename it to myfile.doc.

1. right-click on the file (not the shortcut)
2. Click Rename
3. Erase the .txt from myfile.txt.
4. Type .doc (it is important to have the dot).

Renaming multiple file extensions

If you wish to rename or change the file extensions of multiple files we recommend you enter MS-DOS from Windows and use the above MS-DOS steps.

Unix / Linux users

Change to the directory to the location of where the file is located. In our below example we will rename the file myfile.txt to myfile.htm. Additionally, this example is done from the shell and not a GUI.

mv myfile.txt myfile.htm

Unless an error occurs you should be returned back to the shell prompt

Additional help and information about mv can be found on the mv page.