.\" Automatically generated by Pod::Man 4.14 (Pod::Simple 3.40) .\" .\" Standard preamble: .\" ======================================================================== .de Sp \" Vertical space (when we can't use .PP) .if t .sp .5v .if n .sp .. .de Vb \" Begin verbatim text .ft CW .nf .ne \\$1 .. .de Ve \" End verbatim text .ft R .fi .. .\" Set up some character translations and predefined strings. \*(-- will .\" give an unbreakable dash, \*(PI will give pi, \*(L" will give a left .\" double quote, and \*(R" will give a right double quote. \*(C+ will .\" give a nicer C++. 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Of course, you'll have to process the .\" output yourself in some meaningful fashion. .\" .\" Avoid warning from groff about undefined register 'F'. .de IX .. .nr rF 0 .if \n(.g .if rF .nr rF 1 .if (\n(rF:(\n(.g==0)) \{\ . if \nF \{\ . de IX . tm Index:\\$1\t\\n%\t"\\$2" .. . if !\nF==2 \{\ . nr % 0 . nr F 2 . \} . \} .\} .rr rF .\" ======================================================================== .\" .IX Title "Perl::Critic::Policy::Modules::ProhibitPOSIXimport 3pm" .TH Perl::Critic::Policy::Modules::ProhibitPOSIXimport 3pm "2021-02-28" "perl v5.32.1" "User Contributed Perl Documentation" .\" For nroff, turn off justification. Always turn off hyphenation; it makes .\" way too many mistakes in technical documents. .if n .ad l .nh .SH "NAME" Perl::Critic::Policy::Modules::ProhibitPOSIXimport \- don't import the whole of POSIX into a module .SH "DESCRIPTION" .IX Header "DESCRIPTION" This policy is part of the \f(CW\*(C`Perl::Critic::Pulp\*(C'\fR add-on. It asks you not to \f(CW\*(C`use POSIX\*(C'\fR with an import of all the symbols from that module if you're only using a few things. .PP .Vb 2 \& package Foo; \& use POSIX; # bad .Ve .PP The aim is to save some memory, and maybe run a bit faster. A full \f(CW\*(C`POSIX\*(C'\fR import adds about 550 symbols to your module and that's about 30 to 40 kbytes in Perl 5.10 on a 32\-bit system, or about 115 kbytes in Perl 5.8. If lots of modules do this then it adds up. .PP As noted in the \f(CW\*(C`POSIX\*(C'\fR module docs, the way it exports everything by default is an historical accident, not something to encourage. .SS "Allowed Forms" .IX Subsection "Allowed Forms" A full import is allowed in \f(CW\*(C`package main\*(C'\fR, which is the top-level of a script etc, since in a script you want convenience rather than a bit of memory, at least initially. .PP .Vb 2 \& #!/usr/bin/perl \& use POSIX; # ok .Ve .PP An import of no symbols is allowed and you then add a \f(CW\*(C`POSIX::\*(C'\fR qualifier to each call or constant. Qualifiers like this can make it clear where the function is coming from. .PP .Vb 2 \& package Foo; \& use POSIX (); # ok \& \& my $fd = POSIX::dup(0); \& if ($! == POSIX::ENOENT()) .Ve .PP An import of an explicit set of functions and constants is allowed. This allows short names without the memory penalty of a full import. However it can be error-prone to update the imports with what you actually use (see \&\f(CW\*(C`ProhibitCallsToUndeclaredSubs\*(C'\fR for some checking). .PP .Vb 4 \& package Foo; \& use POSIX qw(dup ENOENT); # ok \& ... \& my $fd = dup(0); .Ve .PP A full import is allowed in a module if there's 15 or more calls to \f(CW\*(C`POSIX\*(C'\fR module functions. This rule might change or be configurable in the future, but the intention is that a module making heavy use of \f(CW\*(C`POSIX\*(C'\fR shouldn't be burdened by a \f(CW\*(C`POSIX::\*(C'\fR on every call or by maintaining a list of explicit imports. .PP .Vb 4 \& package Foo; \& use POSIX; # ok \& ... \& tzset(); dup(1)... # 15 or more calls to POSIX stuff .Ve .SS "Disabling" .IX Subsection "Disabling" If you don't care this sort of thing you can always disable \&\f(CW\*(C`ProhibitPOSIXimport\*(C'\fR from your \fI.perlcriticrc\fR in the usual way (see \&\*(L"\s-1CONFIGURATION\*(R"\s0 in Perl::Critic), .PP .Vb 1 \& [\-Modules::ProhibitPOSIXimport] .Ve .SH "SEE ALSO" .IX Header "SEE ALSO" \&\s-1POSIX\s0, Perl::Critic::Pulp, Perl::Critic, Perl::Critic::Policy::Subroutines::ProhibitCallsToUndeclaredSubs .SH "HOME PAGE" .IX Header "HOME PAGE" .SH "COPYRIGHT" .IX Header "COPYRIGHT" Copyright 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2019, 2021 Kevin Ryde .PP Perl-Critic-Pulp is free software; you can redistribute it and/or modify it under the terms of the \s-1GNU\s0 General Public License as published by the Free Software Foundation; either version 3, or (at your option) any later version. .PP Perl-Critic-Pulp is distributed in the hope that it will be useful, but \&\s-1WITHOUT ANY WARRANTY\s0; without even the implied warranty of \s-1MERCHANTABILITY\s0 or \s-1FITNESS FOR A PARTICULAR PURPOSE.\s0 See the \s-1GNU\s0 General Public License for more details. .PP You should have received a copy of the \s-1GNU\s0 General Public License along with Perl-Critic-Pulp. If not, see .