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diff --git a/upstream/mageia-cauldron/man3pm/open.3pm b/upstream/mageia-cauldron/man3pm/open.3pm new file mode 100644 index 00000000..f262e363 --- /dev/null +++ b/upstream/mageia-cauldron/man3pm/open.3pm @@ -0,0 +1,188 @@ +.\" -*- mode: troff; coding: utf-8 -*- +.\" Automatically generated by Pod::Man 5.01 (Pod::Simple 3.43) +.\" +.\" 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 +.. +.\" \*(C` and \*(C' are quotes in nroff, nothing in troff, for use with C<>. +.ie n \{\ +. ds C` "" +. ds C' "" +'br\} +.el\{\ +. 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 "open 3pm" +.TH open 3pm 2023-12-15 "perl v5.38.2" "Perl Programmers Reference Guide" +.\" 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 +open \- perl pragma to set default PerlIO layers for input and output +.SH SYNOPSIS +.IX Header "SYNOPSIS" +.Vb 7 +\& use open IN => \*(Aq:crlf\*(Aq, OUT => \*(Aq:raw\*(Aq; +\& open my $in, \*(Aq<\*(Aq, \*(Aqfoo.txt\*(Aq or die "open failed: $!"; +\& my $line = <$in>; # CRLF translated +\& close $in; +\& open my $out, \*(Aq>\*(Aq, \*(Aqbar.txt\*(Aq or die "open failed: $!"; +\& print $out $line; # no translation of bytes +\& close $out; +\& +\& use open OUT => \*(Aq:encoding(UTF\-8)\*(Aq; +\& use open IN => \*(Aq:encoding(iso\-8859\-7)\*(Aq; +\& +\& use open IO => \*(Aq:locale\*(Aq; +\& +\& # IO implicit only for :utf8, :encoding, :locale +\& use open \*(Aq:encoding(UTF\-8)\*(Aq; +\& use open \*(Aq:encoding(iso\-8859\-7)\*(Aq; +\& use open \*(Aq:locale\*(Aq; +\& +\& # with :std, also affect global standard handles +\& use open \*(Aq:std\*(Aq, \*(Aq:encoding(UTF\-8)\*(Aq; +\& use open \*(Aq:std\*(Aq, OUT => \*(Aq:encoding(cp1252)\*(Aq; +\& use open \*(Aq:std\*(Aq, IO => \*(Aq:raw :encoding(UTF\-16LE)\*(Aq; +.Ve +.SH DESCRIPTION +.IX Header "DESCRIPTION" +Full-fledged support for I/O layers is now implemented provided +Perl is configured to use PerlIO as its IO system (which has been the +default since 5.8, and the only supported configuration since 5.16). +.PP +The \f(CW\*(C`open\*(C'\fR pragma serves as one of the interfaces to declare default +"layers" (previously known as "disciplines") for all I/O. Any \fBopen()\fR, +\&\fBreadpipe()\fR (aka qx//) and similar operators found within the +lexical scope of this pragma will use the declared defaults via the +\&\f(CW\*(C`${^OPEN}\*(C'\fR variable. +.PP +Layers are specified with a leading colon by convention. You can +specify a stack of multiple layers as a space-separated string. +See PerlIO for more information on the available layers. +.PP +With the \f(CW\*(C`IN\*(C'\fR subpragma you can declare the default layers +of input streams, and with the \f(CW\*(C`OUT\*(C'\fR subpragma you can declare +the default layers of output streams. With the \f(CW\*(C`IO\*(C'\fR subpragma +(may be omitted for \f(CW\*(C`:utf8\*(C'\fR, \f(CW\*(C`:locale\*(C'\fR, or \f(CW\*(C`:encoding\*(C'\fR) you +can control both input and output streams simultaneously. +.PP +When \fBopen()\fR is given an explicit list of layers (with the three-arg +syntax), they override the list declared using this pragma. \fBopen()\fR can +also be given a single colon (:) for a layer name, to override this pragma +and use the default as detailed in +"Defaults and how to override them" in PerlIO. +.PP +To translate from and to an arbitrary text encoding, use the \f(CW\*(C`:encoding\*(C'\fR +layer. The matching of encoding names in \f(CW\*(C`:encoding\*(C'\fR is loose: case does +not matter, and many encodings have several aliases. See +Encode::Supported for details and the list of supported locales. +.PP +If you want to set your encoding layers based on your +locale environment variables, you can use the \f(CW\*(C`:locale\*(C'\fR pseudo-layer. +For example: +.PP +.Vb 9 +\& $ENV{LANG} = \*(Aqru_RU.KOI8\-R\*(Aq; +\& # the :locale will probe the locale environment variables like LANG +\& use open OUT => \*(Aq:locale\*(Aq; +\& open(my $out, \*(Aq>\*(Aq, \*(Aqkoi8\*(Aq) or die "open failed: $!"; +\& print $out chr(0x430); # CYRILLIC SMALL LETTER A = KOI8\-R 0xc1 +\& close $out; +\& open(my $in, \*(Aq<\*(Aq, \*(Aqkoi8\*(Aq) or die "open failed: $!"; +\& printf "%#x\en", ord(<$in>); # this should print 0xc1 +\& close $in; +.Ve +.PP +The logic of \f(CW\*(C`:locale\*(C'\fR is described in full in +"The \f(CW\*(C`:locale\*(C'\fR sub-pragma" in encoding, +but in short it is first trying nl_langinfo(CODESET) and then +guessing from the LC_ALL and LANG locale environment variables. +\&\f(CW\*(C`:locale\*(C'\fR also implicitly turns on \f(CW\*(C`:std\*(C'\fR. +.PP +\&\f(CW\*(C`:std\*(C'\fR is not a layer but an additional subpragma. When specified in the +import list, it activates an additional functionality of pushing the +layers selected for input/output handles to the standard filehandles +(STDIN, STDOUT, STDERR). If the new layers and existing layer stack both +end with an \f(CW\*(C`:encoding\*(C'\fR layer, the existing \f(CW\*(C`:encoding\*(C'\fR layer will also +be removed. +.PP +For example, if both input and out are chosen to be \f(CW:encoding(UTF\-8)\fR, a +\&\f(CW\*(C`:std\*(C'\fR will mean that STDIN, STDOUT, and STDERR will also have +\&\f(CW:encoding(UTF\-8)\fR set. On the other hand, if only output is chosen to +be in \f(CW:encoding(koi8r)\fR, a \f(CW\*(C`:std\*(C'\fR will cause only the STDOUT and STDERR +to be in \f(CW\*(C`koi8r\*(C'\fR. +.PP +The effect of \f(CW\*(C`:std\*(C'\fR is not lexical as it modifies the layer stack of the +global handles. If you wish to apply only this global effect and not the +effect on handles that are opened in that scope, you can isolate the call +to this pragma in its own lexical scope. +.PP +.Vb 1 +\& { use open \*(Aq:std\*(Aq, IO => \*(Aq:encoding(UTF\-8)\*(Aq } +.Ve +.PP +Before Perl 5.34, \f(CW\*(C`:std\*(C'\fR would only apply the first layer provided that is +either \f(CW\*(C`:utf8\*(C'\fR or has a layer argument, e.g. \f(CW:encoding(UTF\-8)\fR. Since +Perl 5.34 it will apply the same layer stack it provides to \f(CW\*(C`${^OPEN}\*(C'\fR. +.SH "IMPLEMENTATION DETAILS" +.IX Header "IMPLEMENTATION DETAILS" +There is a class method in \f(CW\*(C`PerlIO::Layer\*(C'\fR \f(CW\*(C`find\*(C'\fR which is +implemented as XS code. It is called by \f(CW\*(C`import\*(C'\fR to validate the +layers: +.PP +.Vb 1 +\& PerlIO::Layer::\->find("perlio") +.Ve +.PP +The return value (if defined) is a Perl object, of class +\&\f(CW\*(C`PerlIO::Layer\*(C'\fR which is created by the C code in \fIperlio.c\fR. As +yet there is nothing useful you can do with the object at the perl +level. +.SH "SEE ALSO" +.IX Header "SEE ALSO" +"binmode" in perlfunc, "open" in perlfunc, perlunicode, PerlIO, +encoding |