Question

I am new to writing batch files; it’s syntax makes me vomit and so I try to stay away. Long story short, I needed a quick and easy way to check a massive amount of data and export it all to a .csv file in windows. I wrote a simple little batch file to do the work for me.

I am having some issues with variable scope. The idea of this code is to build a string of data separated by commas and then echo the output. another file will catch the output, but that’s not important.

here is some pseudo code which displays the problem I am having, I have run into this problem several times and have restructured my code significantly to try and avoid it

setlocal EnableDelayedExpansion
::pseudo code for loop
LOOP THROUGH LIST OF FILE PATHS PUTTING THEM INTO %%B do (

set str=, ::reset str

other code

if exist %%B ( 

    other code

    ::echos the file path and checks if it is a specific file i need to search
    echo %%B 2> NUL | find /I /N %%B "%phrase_0_%" > NUL
    if %ERRORLEVEL% == 0 ( 

        ::HERE IS THE PROBLEM SEE BELOW FOR MORE INFO

        type %%B 2> NUL | find /I /N "%phrase_1_%" > temp.txt
        set /p var=<temp.txt
        set "str=!str!%var%,"
        del temp.txt

        type %%B 2> NUL | find /I /N "%phrase_2_%" > temp.txt
        set /p var=<temp.txt
        set "str=!str!%var%,"
        del temp.txt
    )

) else ( ::OTHER CODE )

echo !str!
)
endlocal

Ok, here is what I think the problem is. I have been having trouble with nested variable calls. I would have used that handy for loop trick to put output of one command into a variable, but it required another level of nesting which meant even more trouble with changing the value of the variables. as you can see, i can mess with %str% inside the:

if exists %%B(

by using the setlocal EnableDelayedExpansion and !str! nonsense. but that won’t work when i go another level down with

if %ERRORLEVEL% == 0

do you guys have some suggestions on what the problem might be, or what the solution might be?

Answer 1

Delayed expansion will work regardless of the nesting level. But you have other problems here anyway:

set /p var=<temp.txt
set "str=!str!%var%,"

What value do you expect %var% to have there? You’re setting a value and using it in two consecutive lines within a block. You need delayed expansion there as well.