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Perl-Critic-0.09
River stage three • 131 direct dependents • 408 total dependents
130 ++
/ perlcritic

NAME

perlcritic - Command-line interface to critique Perl souce

SYNOPSIS

 perlcritic [options] FILE  #Read from FILE
 perlcritic [options]       #Read from STDIN

DESCRIPTION

perlcritic is the executable front-end to the Perl::Critic engine. The Perl::Critic distribution includes several Policy modules that attempt to enforce the coding standards outlined in Damian Conway's book Perl Best Practices. I highly recommend that you get a copy!

ARGUMENTS

The only argument is the path to the file you wish to analyze. No more than one file can be specified at a time. If the file is not specified, then the input is read from STDIN.

OPTIONS

Option names can be abbreviated to uniqueness, and can be stated with singe or double dashes, and option values can be separated from the option name by a space or '=' (a la Getopt::Long).

-priority N

Sets the the maximum priority value of Policies that should be loaded. 1 is the "highest" priority, and all numbers larger than 1 have "lower" priority. Only Policies that have been configured with a priority value less than or equal to N will not be applied. For a given -profile, increasing N will result in more violations. The default priority is 1. See "CONFIGURATION" for more information.

-profile FILE

Tells perlcritic to use profile named by FILE rather than looking for the default .perlcriticrc file in the current directory or your home directory. See "CONFIGURATION" for more information.

-noprofile

By default, perlcritic looks in several directores for a configuration file named .perlcriticrc. The -noprofile option tells perlcritic not to load any configuration file, thus defaulting to the factory setup, which means that all the Policy modules that are distributed with Perl::Critic will be loaded.

-force

Directs Perl::Critic not to observe the magical ## no critic pseudo-pragma comments in the source code. See "BENDING THE RULES" for more information.

-safari

Report "Perl Best Practice" citations as section numbers from http://safari.oreilly.com instead of page numbers from the actual book. NOTE: This feature is not implemented yet.

-help
-?

Display a brief summary of options and exits.

-man

Display the complete perlcritic manual and exits.

-version

Displays the version number of perlcritic and exits.

CONFIGURATION

The default configuration file is called .perlcriticrc. Perl::Critic will look for this file in the current directory first, and then in your home directory. Alternatively, you can set the PERLCRITIC environment variable to explicitly point to a different configuration file in another location. If none of these files exist, And the -profile option is not given at the command-line, perlcritic defaults to its factory setup, which means that all the policies that are distributed with Perl::Critic will be loaded.

The format of the configuration file is a series of named sections that contain key-value pairs separated by '='. Comments should start with '#' and can be placed on a separate line or after the name-value pairs if you desire. The general recipe is a series of blocks like this:

    [Perl::Critic::Policy::Category::PolicyName]
    priority = 1
    arg1 = value1
    arg2 = value2

Perl::Critic::Policy::Category::PolicyName is the full name of a module that implements the policy you want to load into the engine. The Policy modules distributed with Perl::Critic have been grouped into categories according to the table of contents in Damian Conway's book Perl Best Practices. For brevity, you can ommit the 'Perl::Critic::Policy' part of the module name. The module must be a subclass of Perl::Critic::Policy.

priority is the level of importance you wish to assign to this policy. 1 is the "highest" priority level, and all numbers greater than 1 have increasingly "lower" priority. Only those policies with a priority less than or equal to the -priority value given on the command-line will be loaded. The priority can be an arbitrarily large positive integer. If the priority is not defined, it defaults to 1.

The remaining key-value pairs are configuration parameters for that specific Policy and will be passed into the constructor of the Perl::Critic::Policy subclass. The constructors for most Policy modules do not support arguments, and those that do should have reasonable defaults. See the documentation on the appropriate Policy module for more details.

By default, all the policies that are distributed with Perl::Critic are loaded. Rather than assign a priority level to a Policy, you can simply "turn off" a Policy by prepending a '-' to the name of the module in the config file. In this manner, the Policy will never be loaded, regardless of the -priority option given at the command-line.

A sample configuration might look like this:

    #--------------------------------------------------------------
    # These are really important, so always load them

    [TestingAndDebugging::RequirePackageStricture]
    priority = 1

    [TestingAndDebugging::RequirePackageWarnings]
    priority = 1

    #--------------------------------------------------------------
    # These are less important, so only load when asked

    [Variables::ProhibitPackageVars]
    priority = 2

    [ControlStructures::ProhibitPostfixControls]
    priority = 2

    #--------------------------------------------------------------
    # I don't agree with these, so never load them

    [-NamingConventions::ProhibitMixedCaseVars]
    [-NamingConventions::ProhibitMixedCaseSubs]

THE POLICIES

The following Policy modules are distributed with Perl::Critic. Policy modules have been categorized according to the table of contents in Damian Conway's book Perl Best Practices. Since most coding standards take the form "do this..." or "don't do that...", I have adopted the convention of naming each module RequireSomething or ProhibitSomething. See the documentation of each module for it's specific details.

Perl::Critic::Policy::BuiltinFunctions::ProhibitStringyEval

Perl::Critic::Policy::BuiltinFunctions::RequireBlockGrep

Perl::Critic::Policy::BuiltinFunctions::RequireBlockMap

Perl::Critic::Policy::BuiltinFunctions::RequireGlobFunction

Perl::Critic::Policy::CodeLayout::ProhibitHardTabs

Perl::Critic::Policy::CodeLayout::ProhibitParensWithBuiltins

Perl::Critic::Policy::CodeLayout::RequireTidyCode

Perl::Critic::Policy::ControlStructures::ProhibitCascadingIfElse

Perl::Critic::Policy::ControlStructures::ProhibitCStyleForLoops

Perl::Critic::Policy::ControlStructures::ProhibitPostfixControls

Perl::Critic::Policy::ControlStructures::ProhibitUnlessBlocks

Perl::Critic::Policy::ControlStructures::ProhibitUntilBlocks

Perl::Critic::Policy::InputOutput::ProhibitBacktickOperators

Perl::Critic::Policy::Modules::ProhibitMultiplePackages

Perl::Critic::Policy::Modules::ProhibitRequireStatements

Perl::Critic::Policy::Modules::ProhibitSpecificModules

Perl::Critic::Policy::Modules::ProhibitUnpackagedCode

Perl::Critic::Policy::NamingConventions::ProhibitMixedCaseSubs

Perl::Critic::Policy::NamingConventions::ProhibitMixedCaseVars

Perl::Critic::Policy::Subroutines::ProhibitBuiltinHomonyms

Perl::Critic::Policy::Subroutines::ProhibitExplicitReturnUndef

Perl::Critic::Policy::Subroutines::ProhibitSubroutinePrototypes

Perl::Critic::Policy::TestingAndDebugging::RequirePackageStricture

Perl::Critic::Policy::TestingAndDebugging::RequirePackageWarnings

Perl::Critic::Policy::ValuesAndExpressions::ProhibitConstantPragma

Perl::Critic::Policy::ValuesAndExpressions::ProhibitEmptyQuotes

Perl::Critic::Policy::ValuesAndExpressions::ProhibitInterpolationOfLiterals

Perl::Critic::Policy::ValuesAndExpressions::ProhibitLeadingZeros

Perl::Critic::Policy::ValuesAndExpressions::ProhibitNoisyQuotes

Perl::Critic::Policy::ValuesAndExpressions::RequireInterpolationOfMetachars

Perl::Critic::Policy::ValuesAndExpressions::RequireNumberSeparators

Perl::Critic::Policy::ValuesAndExpressions::RequireQuotedHeredocTerminator

Perl::Critic::Policy::ValuesAndExpressions::RequireUpperCaseHeredocTerminator

Perl::Critic::Policy::Variables::ProhibitLocalVars

Perl::Critic::Policy::Variables::ProhibitPackageVars

Perl::Critic::Policy::Variables::ProhibitPunctuationVars

BENDING THE RULES

NOTE: This feature changed in version 0.09 and is not backward compatible with earlier versions.

Perl::Critic takes a hard-line approach to your code: either you comply or you don't. In the real world, it is not always practical (or even possible) to fully comply with coding standards. In such cases, it is wise to show that you are knowlingly violating the standards and that you have a Damn Good Reason (DGR) for doing so.

To help with those situations, you can direct Perl::Critic to ignore certain lines or blocks of code by using pseudo-pragmas:

    require 'LegacyLibaray1.pl';  ## no critic
    require 'LegacyLibrary2.pl';  ## no critic

    for my $element (@list) {

        ## no critic

        $foo = "";               #Violates 'ProhibitEmptyQuotes'
        $barf = bar() if $foo;   #Violates 'ProhibitPostfixControls'
        #Some more evil code...

        ## use critic

        #Some good code...
        do_something($_);
    }

The ## no critic comments direct Perl::Critic to overlook the remaining lines of code within the block, or until a ## use critic comment is found. If the ## no critic comment is found on the same line as a code statement, then only that line of code is overlooked. To direct perlcritic to ignore the ## no critic comments, use the -force option.

Use this feature wisely. ## no critic should be used in the smallest possible scope, or only on individual lines of code. If Perl::Critic complains about your code, try and find a compliant solution before resorting to this feature.

EDITOR INTEGRATION

For ease-of-use, perlcritic can be integrated with your favorite editor. emacs users can put the following code in your .emacs configuration file:

  (defun perlcritic ()
    (interactive)
    (shell-command-on-region (point) (mark) "perlcritic"))

  (global-set-key "\C-xpc" 'perlcritic)

Pressing "Control-x p c" will run perlcritic on the current region and the output will appear in a separate buffer. My E-Lisp skills are pretty weak, so I'd appreciate any tips for improvement on this. Also, vi fans are welcome to submit similar code and I'll publish it here.

EXIT STATUS

If perlcritic has any errors itself, exits with status == 1. If there are no errors, but perlcritic finds Policy violations in your source code, exits with status == 2. If there were no errors and no violations were found, exits with status == 0.

EXTENDING THE CRITIC

The modular design of Perl::Critic is intended to facilitate the addition of new Policies. To create a new Policy, make a subclass of Perl::Critic::Policy and override the violations() method. Your module should go somewhere in the Perl::Critic::Policy namespace. To use the new Policy, just add it to your .perlcriticrc file. You'll need to have some understanding of PPI, but most Policy modules are pretty straightforward and only require about 20 lines of code.

If you develop any new Policy modules, feel free to send them to <thaljef@cpan.org> and I'll be happy to put them into the Perl::Critic distribution.

BUGS

Scrutinizing Perl code is hard for humans, let alone machines. If you find any bugs, particularly false-positives or false-negatives from a Perl::Critic::Policy, please submit them to http://rt.cpan.org/NoAuth/Bugs.html?Dist=Perl-Critic. Thanks.

CREDITS

Adam Kennedy - For creating PPI, the heart and soul of Perl::Critic.

Damian Conway - For writing Perl Best Practices

Giuseppe Maxia - For all the great ideas and enhancements.

Sharon, my wife - For putting up with my all-night code sessions

AUTHOR

Jeffrey Ryan Thalhammer <thaljef@cpan.org>

COPYRIGHT

Copyright (c) 2005 Jeffrey Ryan Thalhammer. All rights reserved.

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself. The full text of this license can be found in the LICENSE file included with this module.