ren

Use your favourite text editor (as determined by the environment variable $EDITOR) to rename files!

Example Usage

Executing the following commands

$ touch a.txt b.txt c.txy
$ ren

will launch a text editor containing

# Change the file names below as desired.
# Save and quit to perform the rename.
# Do not change the number of lines (including these lines).
a.txt
b.txt
c.txy

and then if we fix the typo like so,

# Change the file names below as desired.
# Save and quit to perform the rename.
# Do not change the number of lines (including these lines).
a.txt
b.txt
c.txt

saving and quitting will yield

Rename commands saved to '/home/sboparen/.ren/fEDScU'.
Renaming 'c.txy' to 'c.txy.TEMP'.
Renaming 'c.txy.TEMP' to 'c.txt'.
Done. To undo, type:
ren -r '/home/sboparen/.ren/fEDScU'

Note that ren can also handle cyclic renames, for example to rename a -> b -> c -> a.

$ echo a >a; echo b >b; echo c >c
$ cat a b c
a
b
c
$ ren
Rename commands saved to '/home/sboparen/.ren/HKNGl6'.
Renaming 'a' to 'a.TEMP'.
Renaming 'b' to 'b.TEMP'.
Renaming 'c' to 'c.TEMP'.
Renaming 'a.TEMP' to 'b'.
Renaming 'b.TEMP' to 'c'.
Renaming 'c.TEMP' to 'a'.
Done. To undo, type:
ren -r '/home/sboparen/.ren/HKNGl6'
$ cat a b c
c
a
b

Notes

I wrote this program a long time ago, but I use it all the time. Also, I last felt the need to modify it in 2011, so I guess it counts as a mature program.

Intentional Limitations

• No attempt was made to handle file names with newlines in them.
• The renaming is done in two stages, where the first stage adds .TEMP to the names of all involved files. ren does simulate the renames before executing them, but it might not come up with a sequence of commands that works if some of your file names already end in .TEMP.

My biggest regret is the way it renames files by creating a hard link and then unlinking the original file name. This can cause problems, most notably:

• It doesn't work at all on filesystems which don't support hard links.
• It essentially never works on directories, since hard links to directories are generally disallowed.

If I had to do it again, I would probably allow the user to specify an external command so that the actual renaming operation can be someone else's problem, and default to mv -n --.