How to identify spacebar in a Batch Script? - batch-file

Question

So, I created a program, which can create and delete folders on the desktop. And I have a problem, when I just write a single space for the name I got the error "Please write a valid folder name!" so it works, but if I'm using more than one spaces, it says "Folder created successfully", and I want to make this program to make an error when I only using spaces in the folder's name. Please help!
Here's a part of my code (the full code is 132 lines long)
set Choice=
set /p Choice="Choose an option: "
if '"%Choice%"'=='"1"' goto masodik
if '"%Choice%"'=='"2"' goto negyedik
if '"%Choice%"'=='"3"' goto otodik
if '"%Choice%"'=='"4"' goto harmadik
if not '"%Choice%"'=='"1"' goto hiba2
if not '"%Choice%"'=='"2"' goto hiba2
if not '"%Choice%"'=='"3"' goto hiba2
if not '"%Choice%"'=='"4"' goto hiba2
:masodik
cls
echo Create a folder
echo ---------------
echo.
cd "%systemdrive%/documents and settings/%username%/desktop"
echo Enter the folder's name!
echo.
set /p mappaneve="The folder's name: "
if "%mappaneve%" EQU "" goto hiba
if EXIST "%mappaneve%" goto hiba3
md "%mappaneve%"
cls
echo Create a folder
echo ---------------
echo.
echo Successfully created "%mappaneve%"!
timeout /t 3 >nul
cls
goto elso

Answer 1

if "%mappaneve: =%" EQU "" goto hiba
ie, replace all spaces with nothing and if the result is nothing then the input must have been all spaces (if that was what you were asking)

Answer 2

quotes is used in variable asignation to make sure space are handle correctly. don't include quotes inside your variable unless when you want to use it.try change your code into this.
set /p "mappaneve=The folder's name: "

Answer 3

Magoo posted the right code in his short answer.
Here is a much longer answer with commented batch code and additional explanations on the various improvements in this code in comparison to code in question post.
set "UserChoice="
set /p "UserChoice=Choose an option: "
if "%UserChoice%" == "1" goto masodik
if "%UserChoice%" == "2" goto negyedik
if "%UserChoice%" == "3" goto otodik
if "%UserChoice%" == "4" goto harmadik
rem None of the 4 valid numbers was entered.
goto hiba2
:masodik
rem Set current directory to desktop directory of current user.
cd /D "%USERPROFILE%\Desktop"
cls
echo Create a folder
echo ---------------
echo.
rem Define a double quote as default value to be able to remove all
rem double qotes from input string with no syntax error even if the
rem user just hits key RETURN or ENTER without entering any string.
set "mappaneve=""
set /p "mappaneve=Enter folder name: "
rem Remove all double quotes from entered folder name.
set "mappaneve=%mappaneve:"=%"
rem Check if user has entered anything at all and if entered folder name
rem does not exist of only 1 or more spaces by using environment variable
rem substitution which removes for string comparison all spaces from the
rem entered folder name.
if "%mappaneve%" == "" goto hiba
if "%mappaneve: =%" == "" goto hiba
rem Appending \* makes sure to test on existence of a folder and not a file.
rem It does not matter if entered folder name ends already with a backslash.
rem Does the folder already exist?
if exist "%mappaneve%\*" goto hiba3
rem Create the folder and verify if that was successful with
rem saving error message into a temporary file for output below.
md "%mappaneve%" 2>"%TEMP%\%~n0_FolderError.tmp"
if errorlevel 1 goto FolderError
rem On successful creation of the folder an empty file is
rem created which should be removed before processing further.
del "%TEMP%\%~n0_FolderError.tmp"
cls
echo Create a folder
echo ---------------
echo.
echo Created successfully "%mappaneve%".
timeout /t 3 >nul
cls
goto elso
:FolderError
cls
echo Failed to create folder "%mappaneve%".
echo.
echo Error message:
echo.
type "%TEMP%\%~n0_FolderError.tmp"
del "%TEMP%\%~n0_FolderError.tmp"
echo.
pause
The improvements are:
Comparing strings with command IF should be done with using surrounding double quotes only. The single quotes are removed from the 4 string comparisons.
Of course if the batch user enters for example "2" (number 2 with double quotes) the batch execution would be exited by command processor because of a syntax error caused by processing if ""2"" == "1" goto masodik. Using delayed variable expansion would be one solution for this issue.
The 4 lines with if not '"%Choice%"'==... can be replaced simply by goto hiba2 as they are all definitely true after the first 4 string comparisons.
choice (SS64 article) is a standard Windows command. Therefore it is advisable to avoid choice (Microsoft article) as name for an environment variable or label. UserChoice (CamelCase spelling for easier reading) is used instead of Choice.
Command choice would be a very good alternative for first user prompt because then the user can't enter something different than 1, 2, 3, or 4.
There is predefined by Windows the environment variable USERPROFILE containing path to the user´s profile directory containing the directory Desktop and other user account related directories. This variable should be used instead of building path with other variables.
The directory separator on Windows is the backslash character and not the forward slash character. Windows supports in the meantime also directory paths with / instead of \, but it is nevertheless better to use the right directory separator.
The user´s profile directory can be on a different drive than system drive. Or the drive from which the batch file is executed is a different one than the drive of user´s profile directory. Therefore it is advisable to use command CD with parameter /D as otherwise changing directory could fail if current drive is different to drive of user´s profile directory.
It is advisable to define a default for an environment variable before prompting a user or clearing the variable. The user can hit just RETURN or ENTER in which case the environment variable keeps its value.
This was done for Choice, but was forgotten for mappaneve.
The user could enter a folder name with double quotes. Therefore it is advisable to remove all double quotes from entered folder name as otherwise the batch script processing would be exited by command processor because of a syntax error on further processing the batch file.
To really test existence of a folder with if exist and not also a file, it is necessary to append \* to the folder name as otherwise if exist could be true also with user input string is name of an existing file.
Creation of folder could fail because of 1 or more invalid characters in folder name, a file exists with same name already, or the user does not have permission to create a folder.
The last reason is very unlikely here with current directory being the desktop directory of the user if user really enters just a folder name and not a directory path to create anywhere a directory (tree) which would be possible here, too.
So it is advisable to test on success on creating the folder.
For understanding the used commands and how they work, open a command prompt window, execute there the following commands, and read entirely all help pages displayed for each command very carefully.
cd /?
cls /?
del /?
echo /?
goto /?
if /?
md /?
rem /?
set /?
timeout /?
type /?
And read also the Microsoft articles:
Testing for a Specific Error Level in Batch Files
Using command redirection operators