Handling trailing backslash & directory names with spaces in batch files

Question

This is a variation of this question: Remove Trailing Slash From Batch File Input

but it's subtly different, so I don't think it's a dupe.

I'm having trouble making this work with directories that have spaces in them (running WinXP).

:START
@echo What folder do you want to process? (Provide a path without a closing backslash)
set /p datapath=

::Is string empty?
IF X%datapath% == X GOTO:START

::Does string have a trailing slash? if so remove it 
IF %datapath:~-1%==\ SET datapath=%datapath:~0,-1%

echo %datapath%

It handles:

c:\

properly (stripping it to c:)

But if you enter:

c:\test space

the error is "space was unexpected at this time."

If you try enter:

"c:\test space"

You get the same error.

I thought it would involve a strategically placed " or two in this line:

IF %datapath:~-1%==\ SET datapath=%datapath:~0,-1%

But I haven't had any luck.

Any ideas?

Answer 1

You can solve it with delayed expansion, because delayed expansion works different than percent expansion.

:START
setlocal EnableDelayedExpansion
@echo What folder do you want to process? (Provide a path without a closing backslash)
set /p datapath=

::Is string empty?
IF X!datapath! == X GOTO:START

::Does string have a trailing slash? if so remove it 
IF !datapath:~-1!==\ SET "datapath=!datapath:~0,-1!"

echo !datapath!

It expands later than the percent expansion, and after the delayed expansion no more parsing is done, so even spaces or special characters have any effect.