windows batch to split string on first occurrence of a delimiter - batch-file

Question

I have a parameter string read from a properties file. One of the properties is as below:
"CUSTOM_JAVA_OPTIONS=-Dhttp.proxyHost=webcache.example.com -Dhttp.proxyPort=8080"
I need to split this string on the first occurrence of "=" and set a parameter with the value:
-Dhttp.proxyHost=webcache.example.com -Dhttp.proxyPort=8080
I am trying to split the string first on the = token and then remove the fist sub-string token from the original string.
In the below code %%G will be set to "CUSTOM_JAVA_OPTIONS" and I am trying to remove this from the original string "TESTSTR"
#echo off
set "TESTSTR=CUSTOM_JAVA_OPTIONS=-Dhttp.proxyHost=webcache.example.com
-Dhttp.proxyPort=8080"
SETLOCAL ENABLEDELAYEDEXPANSION
FOR /F "tokens=1,2 delims==" %%G IN ("%TESTSTR%") DO (
echo Name=%%G
echo Value=%%H
set removestr=%%G
echo TESTSTR=!TESTSTR!
echo removestr=!removestr!
set "str=!TESTSTR:%removestr%=!"
echo str=!str!
)
pause
The above does not seem to work, it produces:
Name=CUSTOM_JAVA_OPTIONS
Value=-Dhttp.proxyHost
TESTSTR=CUSTOM_JAVA_OPTIONS=-Dhttp.proxyHost=webcache.example.com -Dhttp.proxyPort=8080
removestr=CUSTOM_JAVA_OPTIONS
str=TESTSTR:=
Expected result needs to be:
str=-Dhttp.proxyHost=webcache.example.com -Dhttp.proxyPort=8080

Answer 1

This could be simplified to:
#echo off
set "TESTSTR=CUSTOM_JAVA_OPTIONS=-Dhttp.proxyHost=webcache.example.com -Dhttp.proxyPort=8080"
FOR /F "tokens=1* delims==" %%G IN ("%TESTSTR%") DO set "str=%%H"
echo TESTSTR=%TESTSTR%
echo.str=%str%
pause
There are 2 tokens:
1. Text up to 1st delimiter
2. Everything else after first delimiter (*)
Note that by echoing the variables outside of the FOR loop you don't need to enable delayed expansion.

Answer 2

Your code fails entirely because %removestr% is expanded when the command is initially parsed, and your entire loop (code block) is parsed all at once. So %removestr% expands to the value that existed before your loop was entered. In your case, the variable is undefined. So !TESTSTR:%removestr%=! becomes !TESTSTR:=!, which finally becomes TESTSTR:=.
You get closer if you use %%G directly, instead of assigning an environment variable.
set str=!TESTSTR:%%G=! yields =-Dhttp.proxyHost=webcache.example.com -Dhttp.proxyPort=8080
You can then use set str=!str:~1!" to remove the leading =.
set str=!TESTSTR:%%G==! will not work because the search strings stops at the first occurrence of =, so the result is ==-Dhttp.proxyHost=webcache.example.com -Dhttp.proxyPort=8080
The RGuggisberg answer is the most convenient method to get your desired result. (You may want both %%G and %%H).
However, it technically does not break at the first =. It actually breaks at the first string of contiguous = because FOR /F does not parse empty tokens.
So for /f "tokens=1* delims==" %%G in ("A==B==C") yields A for %%G (correct), and B==C (incorrect) for %%H. The correct value should be =B==C.

Answer 3

If the first character after the = character is always a -, then the following method may also work for you:
#Echo Off
Set "TESTSTR=CUSTOM_JAVA_OPTIONS=-Dhttp.proxyHost=webcache.example.com -Dhttp.proxyPort=8080"
Set "REST=-%TESTSTR:*-=%"
Set "FIRST=%TESTSTR:-="&:"%"
Set "FIRST=%FIRST:~,-1%"
Echo [%FIRST%] [%REST%] & Pause
The bottom line is simply to show you the information.