This is all stated in the documentation for require, inclusive the role of %INC: 

if (exists $INC{$filename}) {
    return 1 if $INC{$filename};
    croak "Compilation failed in require";
}

[download]

To import a fle more than once you have to delete from %INC of course.

perl -le'print map{pack c,($-++?1:13)+ord}split//,ESEL'

In reply to Re^5: Is require still required? by shmem
in thread Is require still required? by Bod

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