How to remove trailing and leading whitespace for user-provided input in a batch file?
I know how to do this when the variable is pre-defined. However, when asking for the user to enter in some kind of input, how do I trim leading and trailing whitespace? This is what I have so far:
@echo off
set /p input=:
echo. The input is %input% before
::trim left whitespace
for /f "tokens=* delims= " %%a in ("%input%") do set input=%%a
::trim right whitespace (up to 100 spaces at the end)
for /l %%a in (1,1,100) do if "!input:~-1!"==" " set input=!input:~0,-1!
echo. The input is %input% after
pause
Solution 1:
The solution below works very well for me.
Only 4 lines and works with most (all?) characters.
Solution:
:Trim
SetLocal EnableDelayedExpansion
set Params=%*
for /f "tokens=1*" %%a in ("!Params!") do EndLocal & set %1=%%b
exit /b
Test:
@echo off
call :Test1 & call :Test2 & call :Test3 & exit /b
:Trim
SetLocal EnableDelayedExpansion
set Params=%*
for /f "tokens=1*" %%a in ("!Params!") do EndLocal & set %1=%%b
exit /b
:Test1
set Value= a b c
set Expected=a b c
call :Trim Actual %Value%
if "%Expected%" == "%Actual%" (echo Test1 passed) else (echo Test1 failed)
exit /b
:Test2
SetLocal EnableDelayedExpansion
set Value= a \ / : * ? " ' < > | ` ~ @ # $ [ ] & ( ) + - _ = z
set Expected=a \ / : * ? " ' < > | ` ~ @ # $ [ ] & ( ) + - _ = z
call :Trim Actual !Value!
if !Expected! == !Actual! (echo Test2 passed) else (echo Test2 failed)
exit /b
:Test3
set /p Value="Enter string to trim: " %=%
echo Before: [%Value%]
call :Trim Value %Value%
echo After : [%Value%]
exit /b
Solution 2:
You need to enable delayed expansion. Try this:
@echo off
setlocal enabledelayedexpansion
:blah
set /p input=:
echo."%input%"
for /f "tokens=* delims= " %%a in ("%input%") do set input=%%a
for /l %%a in (1,1,100) do if "!input:~-1!"==" " set input=!input:~0,-1!
echo."%input%"
pause
goto blah
Solution 3:
A very short & easy solution i'm using is this:
@ECHO OFF
SET /p NAME=- NAME ?
ECHO "%NAME%"
CALL :TRIM %NAME% NAME
ECHO "%NAME%"
PAUSE
:TRIM
SET %2=%1
GOTO :EOF
Results in:
- NAME ? my_name
" my_name "
"my_name"