Batch To Remove Character From A String

Question

this may seem basic but Is there a way to create a batch to remove char from a string from a txt file. ?

If I already have this inside the .txt file

2005060.png
2005070.png
2005080.png
2005090.png
so is there a way to create a batch file that will remove the .png at the end to show only this in a new .txt file

2005060
2005070
2005080
2005090

Thanks for any help on this! :)

Answer 1

You can do it as per the following command script:

@setlocal enableextensions enabledelayedexpansion
@echo off
set variable=2005060.png
echo !variable!
if "x!variable:~-4!"=="x.png" (
    set variable=!variable:~0,-4!
)
echo !variable!
endlocal

This outputs:

2005060.png
2005060

The magic line, of course, is:

set variable=!variable:~0,-4!

which removes the last four characters.

---

If you have a file testprog.in with lines it it, like:

2005060.png
1 2 3 4 5      leave this line alone.
2005070.png
2005080.png
2005090.png

you can use a slight modification:

@setlocal enableextensions enabledelayedexpansion
@echo off
for /f "delims=" %%a in (testprog.in) do (
    set variable=%%a
    if "x!variable:~-4!"=="x.png" (
        set variable=!variable:~0,-4!
    )
    echo.!variable!
)
endlocal

which outputs:

2005060
1 2 3 4 5      leave this line alone.
2005070
2005080
2005090

Just keep in mind that it won't output empty lines (though it will do lines with spaces on them).

That may not be a problem depending on what's allowed in your input file. If it is a problem, my advice is to get your hands on either CygWin or GnuWin32 (or Powershell if you have it on your platform) and use some real scripting languages.

Answer 2

If your trying to read a directory of .png files and output a list without extensions? Try this:

    @echo off

    echo. > testprog.txt

    for /R "C:\Users\%USERNAME%\Documents" %%f in (*.png) do (
        echo %%~nf >> testprog.txt
        )

    start testprog.txt