.\" Automatically generated by Pod::Man 4.11 (Pod::Simple 3.35)
.\"
.\" 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 >0, 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
.\" ========================================================================
.\"
.IX Title "strictures 3"
.TH strictures 3 "2019-03-10" "perl v5.26.3" "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"
strictures \- Turn on strict and make most warnings fatal
.SH "SYNOPSIS"
.IX Header "SYNOPSIS"
.Vb 1
\&  use strictures 2;
.Ve
.PP
is equivalent to
.PP
.Vb 10
\&  use strict;
\&  use warnings FATAL => \*(Aqall\*(Aq;
\&  use warnings NONFATAL => qw(
\&    exec
\&    recursion
\&    internal
\&    malloc
\&    newline
\&    experimental
\&    deprecated
\&    portable
\&  );
\&  no warnings \*(Aqonce\*(Aq;
.Ve
.PP
except when called from a file which matches:
.PP
.Vb 1
\&  (caller)[1] =~ /^(?:t|xt|lib|blib)[\e\e\e/]/
.Ve
.PP
and when either \f(CW\*(C`.git\*(C'\fR, \f(CW\*(C`.svn\*(C'\fR, \f(CW\*(C`.hg\*(C'\fR, or \f(CW\*(C`.bzr\*(C'\fR is present in the current
directory (with the intention of only forcing extra tests on the author side)
\&\*(-- or when \f(CW\*(C`.git\*(C'\fR, \f(CW\*(C`.svn\*(C'\fR, \f(CW\*(C`.hg\*(C'\fR, or \f(CW\*(C`.bzr\*(C'\fR is present two directories up
along with \f(CW\*(C`dist.ini\*(C'\fR (which would indicate we are in a \f(CW\*(C`dzil test\*(C'\fR operation,
via Dist::Zilla) \*(-- or when the \f(CW\*(C`PERL_STRICTURES_EXTRA\*(C'\fR environment variable
is set, in which case it also does the equivalent of
.PP
.Vb 3
\&  no indirect \*(Aqfatal\*(Aq;
\&  no multidimensional;
\&  no bareword::filehandles;
.Ve
.PP
Note that \f(CW\*(C`PERL_STRICTURES_EXTRA\*(C'\fR may at some point add even more tests, with
only a minor version increase, but any changes to the effect of \f(CW\*(C`use
strictures\*(C'\fR in normal mode will involve a major version bump.
.PP
If any of the extra testing modules are not present, strictures will
complain loudly, once, via \f(CW\*(C`warn()\*(C'\fR, and then shut up. But you really
should consider installing them, they're all great anti-footgun tools.
.SH "DESCRIPTION"
.IX Header "DESCRIPTION"
I've been writing the equivalent of this module at the top of my code for
about a year now. I figured it was time to make it shorter.
.PP
Things like the importer in \f(CW\*(C`use Moose\*(C'\fR don't help me because they turn
warnings on but don't make them fatal \*(-- which from my point of view is
useless because I want an exception to tell me my code isn't warnings-clean.
.PP
Any time I see a warning from my code, that indicates a mistake.
.PP
Any time my code encounters a mistake, I want a crash \*(-- not spew to \s-1STDERR\s0
and then unknown (and probably undesired) subsequent behaviour.
.PP
I also want to ensure that obvious coding mistakes, like indirect object
syntax (and not so obvious mistakes that cause things to accidentally compile
as such) get caught, but not at the cost of an \s-1XS\s0 dependency and not at the
cost of blowing things up on another machine.
.PP
Therefore, strictures turns on additional checking, but only when it thinks
it's running in a test file in a \s-1VCS\s0 checkout \*(-- although if this causes
undesired behaviour this can be overridden by setting the
\&\f(CW\*(C`PERL_STRICTURES_EXTRA\*(C'\fR environment variable.
.PP
If additional useful author side checks come to mind, I'll add them to the
\&\f(CW\*(C`PERL_STRICTURES_EXTRA\*(C'\fR code path only \*(-- this will result in a minor version
increase (e.g. 1.000000 to 1.001000 (1.1.0) or similar). Any fixes only to the
mechanism of this code will result in a sub-version increase (e.g. 1.000000 to
1.000001 (1.0.1)).
.SH "CATEGORY SELECTIONS"
.IX Header "CATEGORY SELECTIONS"
strictures does not enable fatal warnings for all categories.
.IP "exec" 4
.IX Item "exec"
Includes a warning that can cause your program to continue running
unintentionally after an internal fork.  Not safe to fatalize.
.IP "recursion" 4
.IX Item "recursion"
Infinite recursion will end up overflowing the stack eventually anyway.
.IP "internal" 4
.IX Item "internal"
Triggers deep within perl, in places that are not safe to trap.
.IP "malloc" 4
.IX Item "malloc"
Triggers deep within perl, in places that are not safe to trap.
.IP "newline" 4
.IX Item "newline"
Includes a warning for using stat on a valid but suspect filename, ending in a
newline.
.IP "experimental" 4
.IX Item "experimental"
Experimental features are used intentionally.
.IP "deprecated" 4
.IX Item "deprecated"
Deprecations will inherently be added to in the future in unexpected ways,
so making them fatal won't be reliable.
.IP "portable" 4
.IX Item "portable"
Doesn't indicate an actual problem with the program, only that it may not
behave properly if run on a different machine.
.IP "once" 4
.IX Item "once"
Can't be fatalized.  Also triggers very inconsistently, so we just disable it.
.SH "VERSIONS"
.IX Header "VERSIONS"
Depending on the version of strictures requested, different warnings will be
enabled.  If no specific version is requested, the current version's behavior
will be used.  Versions can be requested using perl's standard mechanism:
.PP
.Vb 1
\&  use strictures 2;
.Ve
.PP
Or, by passing in a \f(CW\*(C`version\*(C'\fR option:
.PP
.Vb 1
\&  use strictures version => 2;
.Ve
.SS "\s-1VERSION 2\s0"
.IX Subsection "VERSION 2"
Equivalent to:
.PP
.Vb 10
\&  use strict;
\&  use warnings FATAL => \*(Aqall\*(Aq;
\&  use warnings NONFATAL => qw(
\&    exec
\&    recursion
\&    internal
\&    malloc
\&    newline
\&    experimental
\&    deprecated
\&    portable
\&  );
\&  no warnings \*(Aqonce\*(Aq;
\&
\&  # and if in dev mode:
\&  no indirect \*(Aqfatal\*(Aq;
\&  no multidimensional;
\&  no bareword::filehandles;
.Ve
.PP
Additionally, any warnings created by modules using warnings::register or
\&\f(CW\*(C`warnings::register_categories()\*(C'\fR will not be fatalized.
.SS "\s-1VERSION 1\s0"
.IX Subsection "VERSION 1"
Equivalent to:
.PP
.Vb 6
\&  use strict;
\&  use warnings FATAL => \*(Aqall\*(Aq;
\&  # and if in dev mode:
\&  no indirect \*(Aqfatal\*(Aq;
\&  no multidimensional;
\&  no bareword::filehandles;
.Ve
.SH "METHODS"
.IX Header "METHODS"
.SS "import"
.IX Subsection "import"
This method does the setup work described above in \*(L"\s-1DESCRIPTION\*(R"\s0.  Optionally
accepts a \f(CW\*(C`version\*(C'\fR option to request a specific version's behavior.
.SS "\s-1VERSION\s0"
.IX Subsection "VERSION"
This method traps the \f(CW\*(C`strictures\->VERSION(1)\*(C'\fR call produced by a use line
with a version number on it and does the version check.
.SH "EXTRA TESTING RATIONALE"
.IX Header "EXTRA TESTING RATIONALE"
Every so often, somebody complains that they're deploying via \f(CW\*(C`git pull\*(C'\fR
and that they don't want strictures to enable itself in this case \*(-- and that
setting \f(CW\*(C`PERL_STRICTURES_EXTRA\*(C'\fR to 0 isn't acceptable (additional ways to
disable extra testing would be welcome but the discussion never seems to get
that far).
.PP
In order to allow us to skip a couple of stages and get straight to a
productive conversation, here's my current rationale for turning the
extra testing on via a heuristic:
.PP
The extra testing is all stuff that only ever blows up at compile time;
this is intentional. So the oft-raised concern that it's different code being
tested is only sort of the case \*(-- none of the modules involved affect the
final optree to my knowledge, so the author gets some additional compile
time crashes which he/she then fixes, and the rest of the testing is
completely valid for all environments.
.PP
The point of the extra testing \*(-- especially \f(CW\*(C`no indirect\*(C'\fR \*(-- is to catch
mistakes that newbie users won't even realise are mistakes without
help. For example,
.PP
.Vb 1
\&  foo { ... };
.Ve
.PP
where foo is an & prototyped sub that you forgot to import \*(-- this is
pernicious to track down since all \fIseems\fR fine until it gets called
and you get a crash. Worse still, you can fail to have imported it due
to a circular require, at which point you have a load order dependent
bug which I've seen before now \fIonly\fR show up in production due to tiny
differences between the production and the development environment. I wrote
<http://shadow.cat/blog/matt\-s\-trout/indirect\-but\-still\-fatal/> to explain
this particular problem before strictures itself existed.
.PP
As such, in my experience so far strictures' extra testing has
\&\fIavoided\fR production versus development differences, not caused them.
.PP
Additionally, strictures' policy is very much \*(L"try and provide as much
protection as possible for newbies \*(-- who won't think about whether there's
an option to turn on or not\*(R" \*(-- so having only the environment variable
is not sufficient to achieve that (I get to explain that you need to add
\&\f(CW\*(C`use strict\*(C'\fR at least once a week on freenode #perl \*(-- newbies sometimes
completely skip steps because they don't understand that that step
is important).
.PP
I make no claims that the heuristic is perfect \*(-- it's already been evolved
significantly over time, especially for 1.004 where we changed things to
ensure it only fires on files in your checkout (rather than strictures\-using
modules you happened to have installed, which was just silly). However, I
hope the above clarifies why a heuristic approach is not only necessary but
desirable from a point of view of providing new users with as much safety as
possible, and will allow any future discussion on the subject to focus on \*(L"how
do we minimise annoyance to people deploying from checkouts intentionally\*(R".
.SH "SEE ALSO"
.IX Header "SEE ALSO"
.IP "\(bu" 4
indirect
.IP "\(bu" 4
multidimensional
.IP "\(bu" 4
bareword::filehandles
.SH "COMMUNITY AND SUPPORT"
.IX Header "COMMUNITY AND SUPPORT"
.SS "\s-1IRC\s0 channel"
.IX Subsection "IRC channel"
irc.perl.org #toolchain
.PP
(or bug 'mst' in query on there or freenode)
.SS "Git repository"
.IX Subsection "Git repository"
Gitweb is on http://git.shadowcat.co.uk/ and the clone \s-1URL\s0 is:
.PP
.Vb 1
\&  git clone git://git.shadowcat.co.uk/p5sagit/strictures.git
.Ve
.PP
The web interface to the repository is at:
.PP
.Vb 1
\&  http://git.shadowcat.co.uk/gitweb/gitweb.cgi?p=p5sagit/strictures.git
.Ve
.SH "AUTHOR"
.IX Header "AUTHOR"
mst \- Matt S. Trout (cpan:MSTROUT) <mst@shadowcat.co.uk>
.SH "CONTRIBUTORS"
.IX Header "CONTRIBUTORS"
Karen Etheridge (cpan:ETHER) <ether@cpan.org>
.PP
Mithaldu \- Christian Walde (cpan:MITHALDU) <walde.christian@gmail.com>
.PP
haarg \- Graham Knop (cpan:HAARG) <haarg@haarg.org>
.SH "COPYRIGHT"
.IX Header "COPYRIGHT"
Copyright (c) 2010 the strictures \*(L"\s-1AUTHOR\*(R"\s0 and \*(L"\s-1CONTRIBUTORS\*(R"\s0
as listed above.
.SH "LICENSE"
.IX Header "LICENSE"
This library is free software and may be distributed under the same terms
as perl itself.