How does the -m switch work in Perl

If you could explain the flow and how/why we can create a module to run with -Mm it w开发者_JAVA技巧ill be helpful

-Mfoo simply generates the code use foo; and places it at the beginning of the code to be compiled.

-mfoo generates use foo ();

-Mfoo=bar,baz generates use foo ('bar','baz'); and so does -mfoo=bar,baz -- that is, there stops being a difference between -M and -m when you use the form with an equal sign, but without it, -m generates the "non-import" form of use.

This is all documented in perlrun.