How to remove trailing and leading whitespace for

Question

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

Answer 1

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"

Answer 2

I'd like to present a compact solution using a call by reference (yes, "batch" has pointers too!) to a function, and a "subfunction":

  @ECHO OFF
  SETLOCAL ENABLEDELAYEDEXPANSION

  SET /p NAME=- NAME ? 
  ECHO "%NAME%"
  CALL :TRIM NAME
  ECHO "%NAME%"
  GOTO :EOF

  :TRIM
  SetLocal EnableDelayedExpansion
  Call :TRIMSUB %%%1%%
  EndLocal & set %1=%tempvar%
  GOTO :EOF

  :TRIMSUB
  set tempvar=%*
  GOTO :EOF

Answer 3

I'm using the "Trim Right Whitespace" exactly working on my "Show-Grp-of-UID.CMD". :) Other idea for improvement are welcome.. ^_^

Answer 4

To improve on Forumpie's answer, the trick is using %*(all params) in the sub:

Edit: Added echo of the TRIM subroutines params, to provide more insight

@ECHO OFF

SET /p NAME=- NAME ? 
ECHO "%NAME%"
CALL :TRIM %NAME%
SET NAME=%TRIMRESULT%
ECHO "%NAME%"

GOTO :EOF

:TRIM
  echo "%1"
  echo "%2"
  echo "%3"
  echo "%4"
  SET TRIMRESULT=%*
GOTO :EOF

This strips leading and trailing spaces, but keeps all spaces between.

"  1 2    3 4    "
"1 2    3 4"

Details of %*: Batch Parameters

Answer 5

I did it like this (temporarily turning on delayed expansion):

      ...
sqlcmd -b -S %COMPUTERNAME% -E -d %DBNAME% -Q "SELECT label from document WHERE label = '%DOCID%';" -h-1 -o Result.txt
      if errorlevel 1 goto INVALID
    :: Read SQL result and trim trailing whitespace
    SET /P ITEM=<Result.txt
    @echo ITEM is %ITEM%.
    setlocal enabledelayedexpansion
    for /l %%a in (1,1,100) do if "!ITEM:~-1!"==" " set ITEM=!ITEM:~0,-1!
    setlocal disabledelayedexpansion
    @echo Var ITEM=%ITEM% now has trailing spaces trimmed.
....

Answer 6

for /f "usebackq tokens=*" %%a in (`echo %StringWithLeadingSpaces%`) do set StringWithout=%%a

This is very simple. for without any parameters considers spaces to be delimiters; setting "*" as the tokens parameter causes the program to gather up all the parts of the string that are not spaces and place them into a new string into which it inserts gaps of its own.