Question

How can i find out whether i am on Windows or not?

I need to execute an OS specific command in AWK.

Specifically, i want to
system("mkdir DIR") on windows and
system("mkdir -p DIR") everywhere else (Unix/Linux/OS X/BSD),
to create a directory recursively.

Answer 1

I can’t test this answer because I don’t have access to a Windows system, but give a try to the ENVIRON variable. Linux and Unix paths are separated with : while Windows paths are separated with ;. You could check it, something like:

awk '
    BEGIN {
        is_windows = 0;
        if ( index( ENVIRON["PATH"], ";" ) > 0 ) {
            is_windows = 1;
        }
    }
    ...
' input-file

This could fail if there is only one directory in the Windows path, but I hope you get the idea. Perhaps a combination of several environment variables or something similar could be more helpful.