Rename Files

Ever since the earliest DOS versions the RENAME and its "twin" (or alias?) REN have been around to allow us to change file names:

REN or RENAME

Renames a file or files.

RENAME [drive:][path]filename1 filename2.
REN [drive:][path]filename1 filename2.

Note that you cannot specify a new drive or path for your destination file.

You can even use wildcards in filename1 (and filename2) to rename, say, all your (very) old MS-DOS (ASCII) help files from *.doc to *.txt:

REN *.doc *.txt

If I remember correctly, in the old MS-DOS days, it was possible to append characters to the file name using the command:

REN *.txt *1.txt

Try that in Windows (XP) and you'll get *.txt1.txt files.

The proper way to do this in NT is:

FOR %%A IN (*.txt) DO REN "%%~fA" "%%~nA1.*"

For each *.txt file, "%%~fA" resolves to the (doublequoted) fully qualified path, and %%~nA1 to the original file name only, with a 1 appended, and .* to leave the extension unaltered.

Undocumented REN

Justin taught me an undocumented REN feature to chop off everything from a file name after the last occurrence of a specified character:

REN testfile.txt *s

will rename testfile.txt to tes.

REN testfile.txt *t

will not change the name at all (remember: the last occurrence...?).

REN testfile.txt *st

will rename testfile.txt to test.
Does that mean chop off everything after the last occurrence of st? No it doesn't:

REN testfile.txt *sa

will rename testfile.txt to tesa, so it seems to mean chop off everything after the last s and then append an a.

Finally:

REN testfile.txt *a

will rename testfile.txt to testfile.txta.

Rename Folders

You can rename folders with the MOVE command:

MOVE d:\path\folder1 folder2

where folder2 is a folder name only (not a fully qualified path).
Make sure folder2 does not exist, neither in d:\path nor in the current folder, or the previous command will really move folder2 into folder1 (making folder2 a subfolder of folder1).

Likewise, MOVE can be used to rename and move files all in one go:

MOVE d:\path1\oldfilename1 e:\path2\newfilename2