Why are strings from text file cut by the FOR loop on passing them to another function?

Question

Prerequisites

I have a file called urls.txt where I store my URLs, e.g.

www.google.de/test1.yaml?at=refs%2Fheads%2Fmaster
www.google.de/test2.yaml?at=refs%2Fheads%2Fmaster
www.google.de/test3.yaml?at=refs%2Fheads%2Fmaster

My goal

Now I want to loop through these URLs and pass them to another function to download them.

:downloader
FOR /F "delims=" %%i IN (urls.txt) DO (call :sub_function %%i)
goto :eof

:sub_function
echo here url is: %~1

Output

The output is that it cuts off the query strings from the URLs and does not pass them completely to the next function.

For example, the output is: www.google.de/test1.yaml?at

What do I miss?

Answer 1

To protect special characters (like the =-sign in your situation, which constitutes a standard token separator just like SPACE, TAB, , and ;), use quotation for the argument, so it is really treated as one.

Then the call command initiates a second %-expansion phase, which is the reason why the %-signs in your argument cause issues (actually the sequence %2 represents the second argument of your script). To circumvent that problem, store the argument string in a variable and ensure that is is going to be expanded during said second %-expansion phase.

Since URLs may also contain the &-symbol, the argument in the sub-function should not become expanded unquoted in order not to misinterpret it as the command concatenation operator.

Here is the corrected code:

:downloader
FOR /F "delims=" %%i IN (urls.txt) DO (
    set "ARG=%%i" & call :sub_function "%%ARG%%"
)
goto :eof

:sub_function
echo here url is: "%~1"