Perl::Critic::Policy::Modules::ProhibitModuleShebang3pm

Overview

This policy is part of the "Perl::Critic::Pulp" add-on. It asks you not to use a "#!" interpreter line in a .pm module file.

    #!/usr/bin/perl -w      <-- bad
    package Foo;
    ...

This "#!" does nothing but might make a reader think it's supposed to be a program instead of a module. Often the "#!" is a leftover cut and paste from a script into a module, perhaps when grabbing a copyright notice or similar intro.

Of course a module works the same with or without, so this policy is low severity and under the "cosmetic" theme (see "POLICY THEMES" in Perl::Critic).

Only the first line of a file is a prospective "#!" interpreter. A "#!" anywhere later is allowed, for example in code which generates other code,

    sub foo {
      print <<HERE;
    #!/usr/bin/make         <-- ok
    # Makefile generated by Foo.pm - DO NOT EDIT
    ...

This policy applies only to .pm files. Anything else, such as ".pl" or ".t" scripts can have "#!", or not, in the usual way. Modules are identified by the .pm filename because it's hard to distinguish a module from a script just by the content.

    [-Modules::ProhibitModuleShebang]

Configuration

"allow_bin_false" (boolean, default true)

If true then allow "#!/bin/false" in module files.

    #! /bin/false           <-- ok

Such a "#!" prevents executing the code if accidentally run as a script. Whether you want this is a personal preference. It indicates a module is not a script and so accords with "ProhibitModuleShebang", but in general it's probably unnecessary.

Home page

<http://user42.tuxfamily.org/perl-critic-pulp/index.html>