FAQ 8.46 What's the difference between require and use?

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8.46: What's the difference between require and use?

    (contributed by brian d foy)

    Perl runs "require" statement at run-time. Once Perl loads, compiles,
    and runs the file, it doesn't do anything else. The "use" statement is
    the same as a "require" run at compile-time, but Perl also calls the
    "import" method for the loaded package. These two are the same:

            use MODULE qw(import list);

            BEGIN {
                    require MODULE;
                    MODULE->import(import list);

    However, you can suppress the "import" by using an explicit, empty
    import list. Both of these still happen at compile-time:

            use MODULE ();

            BEGIN {
                    require MODULE;

    Since "use" will also call the "import" method, the actual value for
    "MODULE" must be a bareword. That is, "use" cannot load files by name,
    although "require" can:

            require "$ENV/lib/Foo.pm"; # no @INC searching!

    See the entry for "use" in perlfunc for more details.


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