CMD nested double quotes in argument

Question

I am having problems with passing arguments to a batch function with nested double quotes.

Here is an example of a batch file:

@SET path_with_space="c:\test\filenamewith space.txt"
@CALL :FUNCTION blaat1, "blaat2 %path_with_space%"
@GOTO :EOF

:FUNCTION
@echo off
echo arg 1: %~1
echo arg 2: %~2
echo arg 3: %~3
GOTO :EOF

The output is:

arg 1: blaat1
arg 2: blaat2 "c:\test\filenamewith
arg 3: space.txt""

What should I do to make arg 2: blaat2 "c:\test\filenamewith space.txt"? Note that I cannot adjust the function or change the %path_with_space%. I can only control what is passed to the function.

Answer 1

Like dbenham said, it's seems impossible to escape a space in a parameter without quotes.
But it could be possible if you know how the receiver function gets the parameters.
Then you could tranfer the parameter via an escaped delayed variable, the variable will be expanded not in the call, it will be expanded just in the function.
And it's necessary that the parameters will be assigned in the function to variables, but this could be the case in a good and readable code.

setlocal EnableDelayedExpansion 
set path_with_space="c:\test\filenamewith space.txt"
@CALL :FUNCTION blaat1, "blaat2 ^!path_with_space^!"
GOTO :EOF

:FUNCTION
@echo off
echo arg 1: %~1
echo arg 2: %~2
echo arg 3: %~3
GOTO :EOF 

The output is:

arg 1: blaat1
arg 2: blaat2 "c:\test\filenamewith space.txt"
arg 3:

EDIT: Soltution with batch injection

This works even when delayed expansion should be always disabled.
But then you need to now how the parameters are expanded in the function.

@echo off
set path_with_space="c:\test\filenamewith space.txt"
CALL :FUNCTION 1 2 ""^^"&call:inject:""
exit/b

:inject
set arg1=blaat1
set arg2=blaat2 %path_with_space%
set arg3=none
exit /b

:FUNCTION
@echo off
set "arg1=%~1"
set "arg2=%~2"
set "arg3=%~3"
echo arg 1: %arg1%
echo arg 2: %arg2%
echo arg 3: %arg3%
GOTO :EOF