How to split string with "=" without for loop in batch file - batch-file

Question

I would like split a string in two part with = as delimiter.
I saw this post but I do not manage ta adapt.
I try this:
set "str=4567=abcde"
echo %str%
set "var1=%str:^=="^&REM #%
echo var1=%var1%
Why it does not work?

Answer 1

While not a bulletproof solution (use the for, artoon), without more info, this can do the work
#echo off
setlocal enableextensions enabledelayedexpansion
set "str=4567=abcde"
rem Step 1 - remove the left part
set "str1=!str:%str%!"
rem Step 2 - Get the right part
set "right=!str:*%str1%!"
rem Step 3 - Get the left part
set "left=!str:%right%=!"
set "left=%left:~0,-1%"
echo [%left%] [%right%]
edited to adapt to comments (OP code in comments adapted to my code, or the reverse)
for /f "delims=" %%i in ('set') do (
setlocal enabledelayedexpansion
rem Step 1 - remove the left part
set "str=%%i"
for %%x in ("!str!") do set "str1=!str:%%~x!"
rem Step 2 - Get the right part
for %%x in ("!str1!") do set "right=!str:*%%~x!"
rem Step 3 - Get the left part
for %%x in ("!right!") do set "left=!str:%%~x=!"
set "left=!left:~0,-1!"
echo [!left!] [!right!]
endlocal
)
And no, as previously indicated this is not bulletproof and some of the variables show problems (had I said it is not bulletproof?).
What i don't understand is the requirement to not use a for loop and then use a for loop. It is a lot easier this way
for /f "tokens=1,* delims==" %%a in ('set') do (
echo [%%a] [%%b]
)
Another alternative (not as easy as the for, more stable than the previous one, non bulletproof) is
for /f %%a in ('set') do (
call :split left right %%a
echo [!left!] [!right!]
)
goto :eof
:split leftVar rightVar data
set "%~1=%~3"
setlocal enabledelayedexpansion
set "data=%*"
set "data=!data:*%1 %2 %3=!"
set "data=%data:~1%"
endlocal & set "%~2=%data%"
goto :eof

Answer 2

As npocmaka commented above, = has special meaning and cannot be replaced with traditional variable string manipulation. If you know the length of either side of the equal sign, you could strip off a number of characters. For example, if "4567" will always be 4 characters, you could set "var1=%str:~0,4%". Or if "abcde" will always be 5 characters, you could set "var1=%str:~0,-6%" (5 chars + 1 for the equal sign).
Otherwise, a for loop is your only other option without using 3rd party utilities.
for /f "delims==" %%I in ("%str%") do set "var1=%%I"
If you've got grep installed, you can do something like:
echo %str% | grep -P -o "^[^=]*"
... but you'd still need to capture its output with another for /f loop.
If you are allergic to for loops, and as an exercise in providing a solution to your question without any regard for efficiency, here's how you get the first half of your string without using a single for loop. Put grep and its dependencies in your %PATH%. Then:
echo %str% | grep -P -o "^[^=]*" >temp.txt
set /P "var1="<temp.txt
del temp.txt
echo %var1%
There, I fixed it!