---
name: "Perl::Critic::Policy::Modules::ProhibitModuleShebang"
section: "3pm"
platform: "linux"
package: "libperl-critic-pulp-perl"
version: "99-1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/Perl::Critic::Policy::Modules::ProhibitModuleShebang"
---

# Perl::Critic::Policy::Modules::ProhibitModuleShebang(3pm)

don't put a #! line at the start of a module file

## NAME

Perl::Critic::Policy::Modules::ProhibitModuleShebang - don't put a #! line at the start of a module file

## DESCRIPTION

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.

### Disabling

If you don't care about this you can always disable `"ProhibitModuleShebang"` from your *.perlcriticrc* in the usual way (see "CONFIGURATION" in Perl::Critic),

```
    [-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.

## SEE ALSO

Perl::Critic::Pulp, Perl::Critic

## HOME PAGE

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

## COPYRIGHT

Copyright 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2019, 2021 Kevin Ryde

Perl-Critic-Pulp is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3, or (at your option) any later version.

Perl-Critic-Pulp is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with Perl-Critic-Pulp.  If not, see \<http://www.gnu.org/licenses\>.