.\" Automatically generated by Pod::Man 2.28 (Pod::Simple 3.28)
.\"
.\" 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++.  Capital omega is used to do unbreakable dashes and
.\" therefore won't be available.  \*(C` and \*(C' expand to `' in nroff,
.\" nothing in troff, for use with C<>.
.tr \(*W-
.ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p'
.ie n \{\
.    ds -- \(*W-
.    ds PI pi
.    if (\n(.H=4u)&(1m=24u) .ds -- \(*W\h'-12u'\(*W\h'-12u'-\" diablo 10 pitch
.    if (\n(.H=4u)&(1m=20u) .ds -- \(*W\h'-12u'\(*W\h'-8u'-\"  diablo 12 pitch
.    ds L" ""
.    ds R" ""
.    ds C` ""
.    ds C' ""
'br\}
.el\{\
.    ds -- \|\(em\|
.    ds PI \(*p
.    ds L" ``
.    ds R" ''
.    ds C`
.    ds C'
'br\}
.\"
.\" Escape single quotes in literal strings from groff's Unicode transform.
.ie \n(.g .ds Aq \(aq
.el       .ds Aq '
.\"
.\" If the F register is turned on, we'll generate index entries on stderr for
.\" titles (.TH), headers (.SH), subsections (.SS), items (.Ip), and index
.\" entries marked with X<> in POD.  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
.\"
.\" Accent mark definitions (@(#)ms.acc 1.5 88/02/08 SMI; from UCB 4.2).
.\" Fear.  Run.  Save yourself.  No user-serviceable parts.
.    \" fudge factors for nroff and troff
.if n \{\
.    ds #H 0
.    ds #V .8m
.    ds #F .3m
.    ds #[ \f1
.    ds #] \fP
.\}
.if t \{\
.    ds #H ((1u-(\\\\n(.fu%2u))*.13m)
.    ds #V .6m
.    ds #F 0
.    ds #[ \&
.    ds #] \&
.\}
.    \" simple accents for nroff and troff
.if n \{\
.    ds ' \&
.    ds ` \&
.    ds ^ \&
.    ds , \&
.    ds ~ ~
.    ds /
.\}
.if t \{\
.    ds ' \\k:\h'-(\\n(.wu*8/10-\*(#H)'\'\h"|\\n:u"
.    ds ` \\k:\h'-(\\n(.wu*8/10-\*(#H)'\`\h'|\\n:u'
.    ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'^\h'|\\n:u'
.    ds , \\k:\h'-(\\n(.wu*8/10)',\h'|\\n:u'
.    ds ~ \\k:\h'-(\\n(.wu-\*(#H-.1m)'~\h'|\\n:u'
.    ds / \\k:\h'-(\\n(.wu*8/10-\*(#H)'\z\(sl\h'|\\n:u'
.\}
.    \" troff and (daisy-wheel) nroff accents
.ds : \\k:\h'-(\\n(.wu*8/10-\*(#H+.1m+\*(#F)'\v'-\*(#V'\z.\h'.2m+\*(#F'.\h'|\\n:u'\v'\*(#V'
.ds 8 \h'\*(#H'\(*b\h'-\*(#H'
.ds o \\k:\h'-(\\n(.wu+\w'\(de'u-\*(#H)/2u'\v'-.3n'\*(#[\z\(de\v'.3n'\h'|\\n:u'\*(#]
.ds d- \h'\*(#H'\(pd\h'-\w'~'u'\v'-.25m'\f2\(hy\fP\v'.25m'\h'-\*(#H'
.ds D- D\\k:\h'-\w'D'u'\v'-.11m'\z\(hy\v'.11m'\h'|\\n:u'
.ds th \*(#[\v'.3m'\s+1I\s-1\v'-.3m'\h'-(\w'I'u*2/3)'\s-1o\s+1\*(#]
.ds Th \*(#[\s+2I\s-2\h'-\w'I'u*3/5'\v'-.3m'o\v'.3m'\*(#]
.ds ae a\h'-(\w'a'u*4/10)'e
.ds Ae A\h'-(\w'A'u*4/10)'E
.    \" corrections for vroff
.if v .ds ~ \\k:\h'-(\\n(.wu*9/10-\*(#H)'\s-2\u~\d\s+2\h'|\\n:u'
.if v .ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'\v'-.4m'^\v'.4m'\h'|\\n:u'
.    \" for low resolution devices (crt and lpr)
.if \n(.H>23 .if \n(.V>19 \
\{\
.    ds : e
.    ds 8 ss
.    ds o a
.    ds d- d\h'-1'\(ga
.    ds D- D\h'-1'\(hy
.    ds th \o'bp'
.    ds Th \o'LP'
.    ds ae ae
.    ds Ae AE
.\}
.rm #[ #] #H #V #F C
.\" ========================================================================
.\"
.IX Title "Perl::Critic::Policy::Variables::ProhibitPunctuationVars 3pm"
.TH Perl::Critic::Policy::Variables::ProhibitPunctuationVars 3pm "2015-08-11" "perl v5.20.2" "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::Variables::ProhibitPunctuationVars \- Write "$EVAL_ERROR" instead of "$@".
.SH "AFFILIATION"
.IX Header "AFFILIATION"
This Policy is part of the core Perl::Critic
distribution.
.SH "DESCRIPTION"
.IX Header "DESCRIPTION"
Perl's vocabulary of punctuation variables such as \f(CW$!\fR, \f(CW$.\fR, and
\&\f(CW$^\fR are perhaps the leading cause of its reputation as inscrutable
line noise.  The simple alternative is to use the English
module to give them clear names.
.PP
.Vb 1
\&  $| = undef;                      #not ok
\&
\&  use English qw(\-no_match_vars);
\&  local $OUTPUT_AUTOFLUSH = undef; #ok
.Ve
.SH "CONFIGURATION"
.IX Header "CONFIGURATION"
The scratch variables \f(CW$_\fR and \f(CW@_\fR are very common and are pretty
well understood, so they are exempt from this policy.  The same goes
for the less-frequently-used default filehandle \f(CW\*(C`_\*(C'\fR used by \fIstat()\fR.
All the regexp capture variables (\f(CW$1\fR, \f(CW$2\fR, ...) are exempt too.
\&\f(CW$]\fR is exempt because there is no English equivalent and
Module::CoreList is based upon it.
.PP
You can add more exceptions to your configuration.  In your
perlcriticrc file, add a block like this:
.PP
.Vb 2
\&  [Variables::ProhibitPunctuationVars]
\&  allow = $@ $!
.Ve
.PP
The \f(CW\*(C`allow\*(C'\fR property  should  be  a  whitespace-delimited  list  of
punctuation variables.
.PP
Other configuration options  control  the  parsing  of  interpolated
strings in the search for forbidden variables. They have  no  effect
on detecting punctuation variables outside of interpolated  strings.
.PP
.Vb 2
\&  [Variables::ProhibitPunctuationVars]
\&  string_mode = thorough
.Ve
.PP
The option \f(CW\*(C`string_mode\*(C'\fR  controls  whether  and  how  interpolated
strings are searched for punctuation variables. Setting
\&\f(CW\*(C`string_mode = thorough\*(C'\fR, the default,  checks  for  special  cases
that may look like punctuation variables  but  aren't,  for  example
\&\f(CW$#foo\fR, an array index count; \f(CW$$bar\fR, a scalar  dereference;  or
\&\f(CW$::baz\fR, a global symbol.
.PP
Setting \f(CW\*(C`string_mode = disable\*(C'\fR causes all interpolated strings  to
be ignored entirely.
.PP
Setting \f(CW\*(C`string_mode = simple\*(C'\fR uses a simple regular expression  to
find matches. In this mode, the magic variables \f(CW$$\fR, \f(CW\*(C`$\*(Aq\*(C'\fR,  \f(CW$#\fR
and \f(CW$:\fR are ignored within interpolated strings due  to  the  high
risk of false positives. Simple mode is  retained  from  an  earlier
draft of the interpolated\- strings code. Its use is only recommended
as a workaround if bugs appear in thorough mode.
.PP
The  \f(CW\*(C`string_mode\*(C'\fR  option  will  go  away  when  the  parsing   of
interpolated strings is implemented in \s-1PPI.\s0 See  \*(L"\s-1CAVEATS\*(R"\s0  below.
.SH "BUGS"
.IX Header "BUGS"
Punctuation variables that confuse \s-1PPI\s0's document parsing may not be
detected  correctly  or  at  all,  and  may  prevent  detection   of
subsequent ones. In particular, \f(CW$"\fR is known to cause difficulties
in interpolated strings.
.SH "CAVEATS"
.IX Header "CAVEATS"
ProhibitPunctuationVars  relies   exclusively   on   \s-1PPI  \s0 to   find
punctuation variables in code, but does all the parsing  itself  for
interpolated strings. When, at some  point,  this  functionality  is
transferred to \s-1PPI,\s0 ProhibitPunctuationVars  will  cease  doing  the
interpolating  and  the  \f(CW\*(C`string_mode\*(C'\fR   option   will   go   away.
.SH "AUTHOR"
.IX Header "AUTHOR"
Jeffrey Ryan Thalhammer <jeff@imaginative\-software.com>
.SH "COPYRIGHT"
.IX Header "COPYRIGHT"
Copyright (c) 2005\-2011 Imaginative Software Systems.  All rights reserved.
.PP
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 \s-1LICENSE\s0 file included with this module.