NAME
Perl::Critic::PolicySummary - Descriptions of the Policy modules included with Perl::Critic itself.
DESCRIPTION
The following Policy modules are distributed with Perl::Critic. (There are additional Policies that can be found in add-on distributions.) The 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
. Each Policy is listed here with its default severity. If you don't agree with the default severity, you can change it in your .perlcriticrc file. See the documentation of each module for its specific details.
POLICIES
Perl::Critic::Policy::BuiltinFunctions::ProhibitBooleanGrep
Use List::MoreUtils::any
instead of grep
in boolean context. [Severity 2]
Perl::Critic::Policy::BuiltinFunctions::ProhibitComplexMappings
Map blocks should have a single statement. [Severity 3]
Perl::Critic::Policy::BuiltinFunctions::ProhibitLvalueSubstr
Use 4-argument substr
instead of writing substr($foo, 2, 6) = $bar
. [Severity 3]
Perl::Critic::Policy::BuiltinFunctions::ProhibitReverseSortBlock
Forbid $b before $a in sort blocks. [Severity 1]
Perl::Critic::Policy::BuiltinFunctions::ProhibitSleepViaSelect
Use Time::HiRes instead of something like select(undef, undef, undef, .05)
. [Severity 5]
Perl::Critic::Policy::BuiltinFunctions::ProhibitStringyEval
Write eval { my $foo; bar($foo) }
instead of eval "my $foo; bar($foo);"
. [Severity 5]
Perl::Critic::Policy::BuiltinFunctions::ProhibitStringySplit
Write split /-/, $string
instead of split '-', $string
. [Severity 2]
Perl::Critic::Policy::BuiltinFunctions::ProhibitUniversalCan
Write eval { $foo->can($name) }
instead of UNIVERSAL::can($foo, $name)
. [Severity 3]
Perl::Critic::Policy::BuiltinFunctions::ProhibitUniversalIsa
Write eval { $foo->isa($pkg) }
instead of UNIVERSAL::isa($foo, $pkg)
. [Severity 3]
Perl::Critic::Policy::BuiltinFunctions::ProhibitVoidGrep
Don't use grep
in void contexts. [Severity 3]
Perl::Critic::Policy::BuiltinFunctions::ProhibitVoidMap
Don't use map
in void contexts. [Severity 3]
Perl::Critic::Policy::BuiltinFunctions::RequireBlockGrep
Write grep { $_ =~ /$pattern/ } @list
instead of grep /$pattern/, @list
. [Severity 4]
Perl::Critic::Policy::BuiltinFunctions::RequireBlockMap
Write map { $_ =~ /$pattern/ } @list
instead of map /$pattern/, @list
. [Severity 4]
Perl::Critic::Policy::BuiltinFunctions::RequireGlobFunction
Use glob q{*}
instead of <*>. [Severity 5]
Perl::Critic::Policy::BuiltinFunctions::RequireSimpleSortBlock
Sort blocks should have a single statement. [Severity 3]
Perl::Critic::Policy::ClassHierarchies::ProhibitAutoloading
AUTOLOAD methods should be avoided. [Severity 3]
Perl::Critic::Policy::ClassHierarchies::ProhibitExplicitISA
Employ use base
instead of @ISA
. [Severity 3]
Perl::Critic::Policy::ClassHierarchies::ProhibitOneArgBless
Write bless {}, $class;
instead of just bless {};
. [Severity 5]
Perl::Critic::Policy::CodeLayout::ProhibitHardTabs
Use spaces instead of tabs. [Severity 3]
Perl::Critic::Policy::CodeLayout::ProhibitParensWithBuiltins
Write open $handle, $path
instead of open($handle, $path)
. [Severity 1]
Perl::Critic::Policy::CodeLayout::ProhibitQuotedWordLists
Write qw(foo bar baz)
instead of ('foo', 'bar', 'baz')
. [Severity 2]
Perl::Critic::Policy::CodeLayout::ProhibitTrailingWhitespace
Don't use whitespace at the end of lines. [Severity 1]
Perl::Critic::Policy::CodeLayout::RequireConsistentNewlines
Use the same newline through the source. [Severity 4]
Perl::Critic::Policy::CodeLayout::RequireTidyCode
Must run code through perltidy. [Severity 1]
Perl::Critic::Policy::CodeLayout::RequireTrailingCommas
Put a comma at the end of every multi-line list declaration, including the last one. [Severity 1]
Perl::Critic::Policy::ControlStructures::ProhibitCStyleForLoops
Write for(0..20)
instead of for($i=0; $i<=20; $i++)
. [Severity 2]
Perl::Critic::Policy::ControlStructures::ProhibitCascadingIfElse
Don't write long "if-elsif-elsif-elsif-elsif...else" chains. [Severity 3]
Perl::Critic::Policy::ControlStructures::ProhibitDeepNests
Don't write deeply nested loops and conditionals. [Severity 3]
Perl::Critic::Policy::ControlStructures::ProhibitLabelsWithSpecialBlockNames
Don't use labels that are the same as the special block names. [Severity 4]
Perl::Critic::Policy::ControlStructures::ProhibitMutatingListFunctions
Don't modify $_
in list functions. [Severity 5]
Perl::Critic::Policy::ControlStructures::ProhibitNegativeExpressionsInUnlessAndUntilConditions
Don't use operators like not
, !~
, and le
within until
and unless
. [Severity 3]
Perl::Critic::Policy::ControlStructures::ProhibitPostfixControls
Write if($condition){ do_something() }
instead of do_something() if $condition
. [Severity 2]
Perl::Critic::Policy::ControlStructures::ProhibitUnlessBlocks
Write if(! $condition)
instead of unless($condition)
. [Severity 2]
Perl::Critic::Policy::ControlStructures::ProhibitUnreachableCode
Don't write code after an unconditional die, exit, or next
. [Severity 4]
Perl::Critic::Policy::ControlStructures::ProhibitUntilBlocks
Write while(! $condition)
instead of until($condition)
. [Severity 2]
Perl::Critic::Policy::Documentation::PodSpelling
Check your spelling. [Severity 1]
Perl::Critic::Policy::Documentation::RequirePackageMatchesPodName
The =head1 NAME
section should match the package. [Severity 1]
Perl::Critic::Policy::Documentation::RequirePodAtEnd
All POD should be after __END__
. [Severity 1]
Perl::Critic::Policy::Documentation::RequirePodLinksIncludeText
Provide text to display with your pod links. [Severity 2]
Perl::Critic::Policy::Documentation::RequirePodSections
Organize your POD into the customary sections. [Severity 2]
Perl::Critic::Policy::ErrorHandling::RequireCarping
Use functions from Carp instead of warn
or die
. [Severity 3]
Perl::Critic::Policy::ErrorHandling::RequireCheckingReturnValueOfEval
You can't depend upon the value of $@
/$EVAL_ERROR
to tell whether an eval
failed. [Severity 3]
Perl::Critic::Policy::InputOutput::ProhibitBacktickOperators
Discourage stuff like @files = `ls $directory`
. [Severity 3]
Perl::Critic::Policy::InputOutput::ProhibitBarewordFileHandles
Write open my $fh, q{<}, $filename;
instead of open FH, q{<}, $filename;
. [Severity 5]
Perl::Critic::Policy::InputOutput::ProhibitExplicitStdin
Use "<>" or "<ARGV>" or a prompting module instead of "<STDIN>". [Severity 4]
Perl::Critic::Policy::InputOutput::ProhibitInteractiveTest
Use prompt() instead of -t. [Severity 5]
Perl::Critic::Policy::InputOutput::ProhibitJoinedReadline
Use local $/ = undef
or File::Slurp instead of joined readline. [Severity 3]
Perl::Critic::Policy::InputOutput::ProhibitOneArgSelect
Never write select($fh)
. [Severity 4]
Perl::Critic::Policy::InputOutput::ProhibitReadlineInForLoop
Write while( $line = <> ){...}
instead of for(<>){...}
. [Severity 4]
Perl::Critic::Policy::InputOutput::ProhibitTwoArgOpen
Write open $fh, q{<}, $filename;
instead of open $fh, "<$filename";
. [Severity 5]
Perl::Critic::Policy::InputOutput::RequireBracedFileHandleWithPrint
Write print {$FH} $foo, $bar;
instead of print $FH $foo, $bar;
. [Severity 1]
Perl::Critic::Policy::InputOutput::RequireBriefOpen
Close filehandles as soon as possible after opening them. [Severity 4]
Perl::Critic::Policy::InputOutput::RequireCheckedClose
Write my $error = close $fh;
instead of close $fh;
. [Severity 2]
Perl::Critic::Policy::InputOutput::RequireCheckedOpen
Write my $error = open $fh, $mode, $filename;
instead of open $fh, $mode, $filename;
. [Severity 3]
Perl::Critic::Policy::InputOutput::RequireCheckedSyscalls
Return value of flagged function ignored. [Severity 1]
Perl::Critic::Policy::Miscellanea::ProhibitFormats
Do not use format
. [Severity 3]
Perl::Critic::Policy::Miscellanea::ProhibitTies
Do not use tie
. [Severity 2]
Perl::Critic::Policy::Miscellanea::ProhibitUnrestrictedNoCritic
Forbid a bare ## no critic
[Severity 3]
Perl::Critic::Policy::Miscellanea::ProhibitUselessNoCritic
Remove ineffective "## no critic" annotations. [Severity 2]
Perl::Critic::Policy::Miscellanea::RequireRcsKeywords
Put source-control keywords in every file. [Severity 2]
Perl::Critic::Policy::Modules::ProhibitAutomaticExportation
Export symbols via @EXPORT_OK
or %EXPORT_TAGS
instead of @EXPORT
. [Severity 4]
Perl::Critic::Policy::Modules::ProhibitEvilModules
Ban modules that aren't blessed by your shop. [Severity 5]
Perl::Critic::Policy::Modules::ProhibitExcessMainComplexity
Minimize complexity in code that is outside of subroutines. [Severity 3]
Perl::Critic::Policy::Modules::ProhibitMultiplePackages
Put packages (especially subclasses) in separate files. [Severity 4]
Perl::Critic::Policy::Modules::RequireBarewordIncludes
Write require Module
instead of require 'Module.pm'
. [Severity 5]
Perl::Critic::Policy::Modules::RequireEndWithOne
End each module with an explicitly 1;
instead of some funky expression. [Severity 4]
Perl::Critic::Policy::Modules::RequireExplicitPackage
Always make the package
explicit. [Severity 4]
Perl::Critic::Policy::Modules::RequireFilenameMatchesPackage
Package declaration must match filename. [Severity 5]
Perl::Critic::Policy::Modules::RequireNoMatchVarsWithUseEnglish
use English
must be passed a -no_match_vars
argument. [Severity 2]
Perl::Critic::Policy::Modules::RequireVersionVar
Give every module a $VERSION
number. [Severity 2]
Perl::Critic::Policy::NamingConventions::Capitalization
Distinguish different program components by case. [Severity 1]
Perl::Critic::Policy::NamingConventions::ProhibitAmbiguousNames
Don't use vague variable or subroutine names like 'last' or 'record'. [Severity 3]
Perl::Critic::Policy::Objects::ProhibitIndirectSyntax
Prohibit indirect object call syntax. [Severity 4]
Perl::Critic::Policy::References::ProhibitDoubleSigils
Write @{ $array_ref }
instead of @$array_ref
. [Severity 2]
Perl::Critic::Policy::RegularExpressions::ProhibitCaptureWithoutTest
Capture variable used outside conditional. [Severity 3]
Perl::Critic::Policy::RegularExpressions::ProhibitComplexRegexes
Split long regexps into smaller qr//
chunks. [Severity 3]
Perl::Critic::Policy::RegularExpressions::ProhibitEnumeratedClasses
Use named character classes instead of explicit character lists. [Severity 1]
Perl::Critic::Policy::RegularExpressions::ProhibitEscapedMetacharacters
Use character classes for literal meta-characters instead of escapes. [Severity 1]
Perl::Critic::Policy::RegularExpressions::ProhibitFixedStringMatches
Use eq
or hash instead of fixed-pattern regexps. [Severity 2]
Perl::Critic::Policy::RegularExpressions::ProhibitSingleCharAlternation
Use [abc]
instead of a|b|c
. [Severity 1]
Perl::Critic::Policy::RegularExpressions::ProhibitUnusedCapture
Only use a capturing group if you plan to use the captured value. [Severity 3]
Perl::Critic::Policy::RegularExpressions::ProhibitUnusualDelimiters
Use only //
or {}
to delimit regexps. [Severity 1]
Perl::Critic::Policy::RegularExpressions::RequireBracesForMultiline
Use {
and }
to delimit multi-line regexps. [Severity 1]
Perl::Critic::Policy::RegularExpressions::RequireDotMatchAnything
Always use the /s
modifier with regular expressions. [Severity 2]
Perl::Critic::Policy::RegularExpressions::RequireExtendedFormatting
Always use the /x
modifier with regular expressions. [Severity 3]
Perl::Critic::Policy::RegularExpressions::RequireLineBoundaryMatching
Always use the /m
modifier with regular expressions. [Severity 2]
Perl::Critic::Policy::Subroutines::ProhibitAmpersandSigils
Don't call functions with a leading ampersand sigil. [Severity 2]
Perl::Critic::Policy::Subroutines::ProhibitBuiltinHomonyms
Don't declare your own open
function. [Severity 4]
Perl::Critic::Policy::Subroutines::ProhibitExcessComplexity
Minimize complexity by factoring code into smaller subroutines. [Severity 3]
Perl::Critic::Policy::Subroutines::ProhibitExplicitReturnUndef
Return failure with bare return
instead of return undef
. [Severity 5]
Perl::Critic::Policy::Subroutines::ProhibitManyArgs
Too many arguments. [Severity 3]
Perl::Critic::Policy::Subroutines::ProhibitNestedSubs
sub never { sub correct {} }
. [Severity 5]
Perl::Critic::Policy::Subroutines::ProhibitReturnSort
Behavior of sort
is not defined if called in scalar context. [Severity 5]
Perl::Critic::Policy::Subroutines::ProhibitSubroutinePrototypes
Don't write sub my_function (@@) {}
. [Severity 5]
Perl::Critic::Policy::Subroutines::ProhibitUnusedPrivateSubroutines
Prevent unused private subroutines. [Severity 3]
Perl::Critic::Policy::Subroutines::ProtectPrivateSubs
Prevent access to private subs in other packages. [Severity 3]
Perl::Critic::Policy::Subroutines::RequireArgUnpacking
Always unpack @_
first. [Severity 4]
Perl::Critic::Policy::Subroutines::RequireFinalReturn
End every path through a subroutine with an explicit return
statement. [Severity 4]
Perl::Critic::Policy::TestingAndDebugging::ProhibitNoStrict
Prohibit various flavors of no strict
. [Severity 5]
Perl::Critic::Policy::TestingAndDebugging::ProhibitNoWarnings
Prohibit various flavors of no warnings
. [Severity 4]
Perl::Critic::Policy::TestingAndDebugging::ProhibitProlongedStrictureOverride
Don't turn off strict for large blocks of code. [Severity 4]
Perl::Critic::Policy::TestingAndDebugging::RequireTestLabels
Tests should all have labels. [Severity 3]
Perl::Critic::Policy::TestingAndDebugging::RequireUseStrict
Always use strict
. [Severity 5]
Perl::Critic::Policy::TestingAndDebugging::RequireUseWarnings
Always use warnings
. [Severity 4]
Perl::Critic::Policy::ValuesAndExpressions::ProhibitCommaSeparatedStatements
Don't use the comma operator as a statement separator. [Severity 4]
Perl::Critic::Policy::ValuesAndExpressions::ProhibitComplexVersion
Prohibit version values from outside the module. [Severity 3]
Perl::Critic::Policy::ValuesAndExpressions::ProhibitConstantPragma
Don't use constant FOO => 15
. [Severity 4]
Perl::Critic::Policy::ValuesAndExpressions::ProhibitEmptyQuotes
Write q{}
instead of ''
. [Severity 2]
Perl::Critic::Policy::ValuesAndExpressions::ProhibitEscapedCharacters
Write "\N{DELETE}"
instead of "\x7F"
, etc. [Severity 2]
Perl::Critic::Policy::ValuesAndExpressions::ProhibitImplicitNewlines
Use concatenation or HEREDOCs instead of literal line breaks in strings. [Severity 3]
Perl::Critic::Policy::ValuesAndExpressions::ProhibitInterpolationOfLiterals
Always use single quotes for literal strings. [Severity 1]
Perl::Critic::Policy::ValuesAndExpressions::ProhibitLeadingZeros
Write oct(755)
instead of 0755
. [Severity 5]
Perl::Critic::Policy::ValuesAndExpressions::ProhibitLongChainsOfMethodCalls
Long chains of method calls indicate tightly coupled code. [Severity 2]
Perl::Critic::Policy::ValuesAndExpressions::ProhibitMagicNumbers
Don't use values that don't explain themselves. [Severity 2]
Perl::Critic::Policy::ValuesAndExpressions::ProhibitMismatchedOperators
Don't mix numeric operators with string operands, or vice-versa. [Severity 3]
Perl::Critic::Policy::ValuesAndExpressions::ProhibitMixedBooleanOperators
Write !$foo && $bar || $baz
instead of not $foo && $bar or $baz
. [Severity 4]
Perl::Critic::Policy::ValuesAndExpressions::ProhibitNoisyQuotes
Use q{}
or qq{}
instead of quotes for awkward-looking strings. [Severity 2]
Perl::Critic::Policy::ValuesAndExpressions::ProhibitQuotesAsQuotelikeOperatorDelimiters
Don't use quotes ('
, "
, `
) as delimiters for the quote-like operators. [Severity 3]
Perl::Critic::Policy::ValuesAndExpressions::ProhibitSpecialLiteralHeredocTerminator
Don't write print <<'__END__'
. [Severity 3]
Perl::Critic::Policy::ValuesAndExpressions::ProhibitVersionStrings
Don't use strings like v1.4
or 1.4.5
when including other modules. [Severity 3]
Perl::Critic::Policy::ValuesAndExpressions::RequireConstantVersion
Require $VERSION to be a constant rather than a computed value. [Severity 2]
Perl::Critic::Policy::ValuesAndExpressions::RequireInterpolationOfMetachars
Warns that you might have used single quotes when you really wanted double-quotes. [Severity 1]
Perl::Critic::Policy::ValuesAndExpressions::RequireNumberSeparators
Write 141_234_397.0145
instead of 141234397.0145
. [Severity 2]
Perl::Critic::Policy::ValuesAndExpressions::RequireQuotedHeredocTerminator
Write print <<'THE_END'
or print <<"THE_END"
. [Severity 3]
Perl::Critic::Policy::ValuesAndExpressions::RequireUpperCaseHeredocTerminator
Write <<'THE_END';
instead of <<'theEnd';
. [Severity 2]
Perl::Critic::Policy::Variables::ProhibitConditionalDeclarations
Do not write my $foo = $bar if $baz;
. [Severity 5]
Perl::Critic::Policy::Variables::ProhibitEvilVariables
Ban variables that aren't blessed by your shop. [Severity 5]
Perl::Critic::Policy::Variables::ProhibitLocalVars
Use my
instead of local
, except when you have to. [Severity 2]
Perl::Critic::Policy::Variables::ProhibitMatchVars
Avoid $`
, $&
, $'
and their English equivalents. [Severity 4]
Perl::Critic::Policy::Variables::ProhibitPackageVars
Eliminate globals declared with our
or use vars
. [Severity 3]
Perl::Critic::Policy::Variables::ProhibitPerl4PackageNames
Use double colon (::) to separate package name components instead of single quotes ('). [Severity 2]
Perl::Critic::Policy::Variables::ProhibitPunctuationVars
Write $EVAL_ERROR
instead of $@
. [Severity 2]
Perl::Critic::Policy::Variables::ProhibitReusedNames
Do not reuse a variable name in a lexical scope [Severity 3]
Perl::Critic::Policy::Variables::ProhibitUnusedVariables
Don't ask for storage you don't need. [Severity 3]
Perl::Critic::Policy::Variables::ProtectPrivateVars
Prevent access to private vars in other packages. [Severity 3]
Perl::Critic::Policy::Variables::RequireInitializationForLocalVars
Write local $foo = $bar;
instead of just local $foo;
. [Severity 3]
Perl::Critic::Policy::Variables::RequireLexicalLoopIterators
Write for my $element (@list) {...}
instead of for $element (@list) {...}
. [Severity 5]
Perl::Critic::Policy::Variables::RequireLocalizedPunctuationVars
Magic variables should be assigned as "local". [Severity 4]
Perl::Critic::Policy::Variables::RequireNegativeIndices
Negative array index should be used. [Severity 4]
VERSION
This is part of Perl::Critic version 1.105_02.
AUTHOR
Jeffrey Ryan Thalhammer <jeff@imaginative-software.com>
COPYRIGHT
Copyright (c) 2005-2010 Imaginative Software Systems. 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.