sam-t2/devtools/amd64/man/man3/warnings.3

.\" Automatically generated by Pod::Man v1.37, Pod::Parser v1.32
.\"
.\" Standard preamble:
.\" ========================================================================
.de Sh \" Subsection heading
.br
.if t .Sp
.ne 5
.PP
\fB\\$1\fR
.PP
..
.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.  | will give a
.\" real vertical bar.  \*(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-|\(bv\*(Tr
.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" ''
'br\}
.\"
.\" If the F register is turned on, we'll generate index entries on stderr for
.\" titles (.TH), headers (.SH), subsections (.Sh), items (.Ip), and index
.\" entries marked with X<> in POD.  Of course, you'll have to process the
.\" output yourself in some meaningful fashion.
.if \nF \{\
.    de IX
.    tm Index:\\$1\t\\n%\t"\\$2"
..
.    nr % 0
.    rr F
.\}
.\"
.\" For nroff, turn off justification.  Always turn off hyphenation; it makes
.\" way too many mistakes in technical documents.
.hy 0
.if n .na
.\"
.\" 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 "warnings 3"
.TH warnings 3 "2001-09-21" "perl v5.8.8" "Perl Programmers Reference Guide"
.SH "NAME"
warnings \- Perl pragma to control optional warnings
.SH "SYNOPSIS"
.IX Header "SYNOPSIS"
.Vb 2
\&    use warnings;
\&    no warnings;
.Ve
.PP
.Vb 2
\&    use warnings "all";
\&    no warnings "all";
.Ve
.PP
.Vb 4
\&    use warnings::register;
\&    if (warnings::enabled()) {
\&        warnings::warn("some warning");
\&    }
.Ve
.PP
.Vb 3
\&    if (warnings::enabled("void")) {
\&        warnings::warn("void", "some warning");
\&    }
.Ve
.PP
.Vb 3
\&    if (warnings::enabled($object)) {
\&        warnings::warn($object, "some warning");
\&    }
.Ve
.PP
.Vb 3
\&    warnings::warnif("some warning");
\&    warnings::warnif("void", "some warning");
\&    warnings::warnif($object, "some warning");
.Ve
.SH "DESCRIPTION"
.IX Header "DESCRIPTION"
The \f(CW\*(C`warnings\*(C'\fR pragma is a replacement for the command line flag \f(CW\*(C`\-w\*(C'\fR,
but the pragma is limited to the enclosing block, while the flag is global.
See perllexwarn for more information.
.PP
If no import list is supplied, all possible warnings are either enabled
or disabled.
.PP
A number of functions are provided to assist module authors.
.IP "use warnings::register" 4
.IX Item "use warnings::register"
Creates a new warnings category with the same name as the package where
the call to the pragma is used.
.IP "\fIwarnings::enabled()\fR" 4
.IX Item "warnings::enabled()"
Use the warnings category with the same name as the current package.
.Sp
Return \s-1TRUE\s0 if that warnings category is enabled in the calling module.
Otherwise returns \s-1FALSE\s0.
.IP "warnings::enabled($category)" 4
.IX Item "warnings::enabled($category)"
Return \s-1TRUE\s0 if the warnings category, \f(CW$category\fR, is enabled in the
calling module.
Otherwise returns \s-1FALSE\s0.
.IP "warnings::enabled($object)" 4
.IX Item "warnings::enabled($object)"
Use the name of the class for the object reference, \f(CW$object\fR, as the
warnings category.
.Sp
Return \s-1TRUE\s0 if that warnings category is enabled in the first scope
where the object is used.
Otherwise returns \s-1FALSE\s0.
.IP "warnings::warn($message)" 4
.IX Item "warnings::warn($message)"
Print \f(CW$message\fR to \s-1STDERR\s0.
.Sp
Use the warnings category with the same name as the current package.
.Sp
If that warnings category has been set to \*(L"\s-1FATAL\s0\*(R" in the calling module
then die. Otherwise return.
.ie n .IP "warnings::warn($category, $message)" 4
.el .IP "warnings::warn($category, \f(CW$message\fR)" 4
.IX Item "warnings::warn($category, $message)"
Print \f(CW$message\fR to \s-1STDERR\s0.
.Sp
If the warnings category, \f(CW$category\fR, has been set to \*(L"\s-1FATAL\s0\*(R" in the
calling module then die. Otherwise return.
.ie n .IP "warnings::warn($object, $message)" 4
.el .IP "warnings::warn($object, \f(CW$message\fR)" 4
.IX Item "warnings::warn($object, $message)"
Print \f(CW$message\fR to \s-1STDERR\s0.
.Sp
Use the name of the class for the object reference, \f(CW$object\fR, as the
warnings category.
.Sp
If that warnings category has been set to \*(L"\s-1FATAL\s0\*(R" in the scope where \f(CW$object\fR
is first used then die. Otherwise return.
.IP "warnings::warnif($message)" 4
.IX Item "warnings::warnif($message)"
Equivalent to:
.Sp
.Vb 2
\&    if (warnings::enabled())
\&      { warnings::warn($message) }
.Ve
.ie n .IP "warnings::warnif($category, $message)" 4
.el .IP "warnings::warnif($category, \f(CW$message\fR)" 4
.IX Item "warnings::warnif($category, $message)"
Equivalent to:
.Sp
.Vb 2
\&    if (warnings::enabled($category))
\&      { warnings::warn($category, $message) }
.Ve
.ie n .IP "warnings::warnif($object, $message)" 4
.el .IP "warnings::warnif($object, \f(CW$message\fR)" 4
.IX Item "warnings::warnif($object, $message)"
Equivalent to:
.Sp
.Vb 2
\&    if (warnings::enabled($object))
\&      { warnings::warn($object, $message) }
.Ve
.PP
See \*(L"Pragmatic Modules\*(R" in perlmodlib and perllexwarn.