identify or delete equal sign (=) in Windows command script environment variable - batch-file

Question

Is there methods to do the subject? For example, we can't simply replace equal sign usual way through substring replacing syntax %variable:substring1=substring2%, because substring1 can't contain equal sign.

Answer 1

What about a simple loop that walks through the string and checks every character against =?
#echo off
setlocal EnableExtensions DisableDelayedExpansion
rem // Define constants here:
set "STRING=%~1" & rem // (string from first command line argument)
set "SEARCH==" & rem // (specify a single character here)
set "REPLAC=" & rem // (specify an arbitrary string here)
rem // Check search string for validity (one character):
if not defined SEARCH ((>&2 echo ERROR: no search string defined!) & exit /B 1)
setlocal EnableDelayedExpansion
if not "!SEARCH:~1!"=="" ((>&2 echo ERROR: search string too long^^!) & exit /B 1)
rem // Loop through each character of the string:
set "RESULT="
:LOOP
if not defined STRING goto :QUIT
rem // Compare current character with search string:
set "CHAR=!STRING:~,1!"
if "!CHAR!"=="!SEARCH!" (
rem // Match found, so replace character:
set "RESULT=!RESULT!!REPLAC!"
) else (
rem // No match found, so keep character:
set "RESULT=!RESULT!!CHAR!"
)
rem // Remove processed character from (remaining) string:
set "STRING=!STRING:~1!"
goto :LOOP
:QUIT
rem // Return result here finally:
echo(!RESULT!
endlocal
endlocal
exit /B
This should be a bit better in terms of performance, because there are less string manipulations:
#echo off
setlocal EnableExtensions DisableDelayedExpansion
rem // Define constants here:
set "STRING=%~1" & rem // (string from first command line argument)
set "SEARCH==" & rem // (specify a single character here)
set "REPLAC=" & rem // (specify an arbitrary string here)
rem // Check search string for validity (one character):
if not defined SEARCH ((>&2 echo ERROR: no search string defined!) & exit /B 1)
setlocal EnableDelayedExpansion
if not "!SEARCH:~1!"=="" ((>&2 echo ERROR: search string too long^^!) & exit /B 1)
rem // Loop through each character of the string:
set /A "INDEX=0" & set "RESULT="
if not defined STRING goto :QUIT
:LOOP
rem // Compare currently indexed character with search string:
set "CHAR=!STRING:~%INDEX%,1!"
if not defined CHAR goto :QUIT
if "!CHAR!"=="!SEARCH!" (
rem // Match found, so replace character:
set "RESULT=!RESULT!!REPLAC!"
) else (
rem // No match found, so keep character:
set "RESULT=!RESULT!!CHAR!"
)
rem // Increment character index:
set /A "INDEX+=1"
goto :LOOP
:QUIT
rem // Return result here finally:
echo(!RESULT!
endlocal
endlocal
exit /B

Answer 2

here's one way (the idea is to split it with for /f and replace the equal signs with same amount of replacements calculating their length with strlen function):
#echo off
rem ===== testing the function =======
set "eqs====abcd=abcd===abcdabcd======~*"
set replace_with=X1
echo %eqs%
call :eqreplacer "%eqs%" %replace_with% res
echo %res%
exit /b %errorlevel%
rem ===============================
:eqreplacer String Replacer [RtnVar]
setlocal
rem the result of the operation will be stored here
set "result=#%~1#"
set "replacer=%~2"
call :strlen0 result wl
call :strlen0 replacer rl
:start
set "part1="
set "part2="
rem splitting the string on two parts
for /f "tokens=1* delims==" %%w in ("%result%") do (
set "part1=%%w"
set "part2=%%x"
)
rem calculating the count replace strings we should use
call :strlen0 part1 p1l
call :strlen0 part2 p2l
set /a iteration_end=wl-p1l-p2l
rem creating a sequence with replaced strings
setlocal enableDelayedExpansion
set "sequence="
for /l %%i in (1,1,%iteration_end%) do (
set sequence=!sequence!%replacer%
)
endlocal & set "sequence=%sequence%"
rem adjust the string length
set /a wl=wl+iteration_end*(rl-1)
rem replacing for the current iteration
set result=%part1%%sequence%%part2%
rem if the second part is empty the task is over
if "%part2%" equ "" (
set result=%result:~1,-1%
goto :endloop
)
goto :start
:endloop
endlocal & if "%~3" neq "" (set %~3=%result%) else echo %result%
exit /b
:strlen0 StrVar [RtnVar]
setlocal EnableDelayedExpansion
set "s=#!%~1!"
set "len=0"
for %%N in (4096 2048 1024 512 256 128 64 32 16 8 4 2 1) do (
if "!s:~%%N,1!" neq "" (
set /a "len+=%%N"
set "s=!s:~%%N!"
)
)
endlocal&if "%~2" neq "" (set %~2=%len%) else echo %len%
exit /b
here you can find more solutions.Take a look at dbenham's post.

Answer 3

Simple way to identify =.
echo "%variable%"|find "=">nul
if not errorlevel 1 echo equal sign detected