Execute a Perl sub routine via the command prompt?

Question

I have a perl (.pm) file with multiple sub routines. I want to execute one sub routine which takes a single parameter as argument. I tried

perl /full_file_path/file_name.pm mySubRoutine myArgument

but nothing was returned. What is the correct format?

Answer 1

If your Perl module is in one of the @INC list of directories then you can write

perl -Mfile_name -e 'mySubRoutine(myArgument)'

if it is elsewhere then you need to add the path, like

perl -M/full_file_path/file_name -e 'mySubRoutine(myArgument)'

and, as ysth points out, if the module file has a package MyPackage at the start then you may need to add that to your call, like

perl -M/full_file_path/file_name -e 'MyPackage::mySubRoutine(myArgument)'

however in that case the file should be called MyPackage.pm and the actual command would look something like below (notice that there is no .pm appended to filename when used with -M argument.

perl -M/full_file_path/MyPackage -e 'MyPackage::mySubRoutine(myArgument)'