The new(er) way of controlling Unicode I/O (and other) features;

[p5sagit/p5-mst-13.2.git] / pod / perluniintro.pod

diff --git a/pod/perluniintro.pod b/pod/perluniintro.pod
index 870926e..33400fc 100644 (file)
--- a/pod/perluniintro.pod
+++ b/pod/perluniintro.pod
@@ -172,14 +172,17 @@ To output UTF-8, use the C<:utf8> output layer.  Prepending
 to this sample program ensures that the output is completely UTF-8,
 and removes the program's warning.
 
-If your locale environment variables (C<LANGUAGE>, C<LC_ALL>,
-C<LC_CTYPE>, C<LANG>) contain the strings 'UTF-8' or 'UTF8',
-regardless of case, then the default encoding of your STDIN, STDOUT,
-and STDERR and of B<any subsequent file open>, is UTF-8.  Note that
-this means that Perl expects other software to work, too: if Perl has
-been led to believe that STDIN should be UTF-8, but then STDIN coming
-in from another command is not UTF-8, Perl will complain about the
-malformed UTF-8.
+If your locale environment variables (C<LC_ALL>, C<LC_CTYPE>, C<LANG>)
+contain the strings 'UTF-8' or 'UTF8' (matched case-insensitively)
+B<and> you enable using UTF-8 either by using the C<-C> command line
+switch or by setting the PERL_UNICODE environment variable to an empty
+string, C<"">, (see L<perlrun> and the documentation for the C<-C>
+switch for more information about the possible values), then the
+default encoding of your STDIN, STDOUT, and STDERR, and of B<any
+subsequent file open>, will be UTF-8.  Note that this means that Perl
+expects other software to work, too: if Perl has been led to believe
+that STDIN should be UTF-8, but then STDIN coming in from another
+command is not UTF-8, Perl will complain about the malformed UTF-8.
 
 All features that combine Unicode and I/O also require using the new
 PerlIO feature.  Almost all Perl 5.8 platforms do use PerlIO, though:
@@ -361,7 +364,7 @@ the C<open> pragma.  See L<open>, or look at the following example.
 
 With the C<open> pragma you can use the C<:locale> layer
 
-    $ENV{LC_ALL} = $ENV{LANG} = 'ru_RU.KOI8-R';
+    BEGIN { $ENV{LC_ALL} = $ENV{LANG} = 'ru_RU.KOI8-R' }
     # the :locale will probe the locale environment variables like LC_ALL
     use open OUT => ':locale'; # russki parusski
     open(O, ">koi8");
@@ -398,9 +401,9 @@ written to the stream. For example, the following snippet copies the
 contents of the file "text.jis" (encoded as ISO-2022-JP, aka JIS) to
 the file "text.utf8", encoded as UTF-8:
 
-    open(my $nihongo, '<:encoding(iso2022-jp)', 'text.jis');
-    open(my $unicode, '>:utf8',                 'text.utf8');
-    while (<$nihongo>) { print $unicode }
+    open(my $nihongo, '<:encoding(iso-2022-jp)', 'text.jis');
+    open(my $unicode, '>:utf8',                  'text.utf8');
+    while (<$nihongo>) { print $unicode $_ }
 
 The naming of encodings, both by the C<open()> and by the C<open>
 pragma, is similar to the C<encoding> pragma in that it allows for
@@ -433,7 +436,8 @@ UTF-8 encoded.  A C<use open ':utf8'> would have avoided the bug, or
 explicitly opening also the F<file> for input as UTF-8.
 
 B<NOTE>: the C<:utf8> and C<:encoding> features work only if your
-Perl has been built with the new PerlIO feature.
+Perl has been built with the new PerlIO feature (which is the default
+on most systems).
 
 =head2 Displaying Unicode As Text
 
@@ -862,7 +866,7 @@ If you have the GNU recode installed, you can also use the
 Perl front-end C<Convert::Recode> for character conversions.
 
 The following are fast conversions from ISO 8859-1 (Latin-1) bytes
-to UTF-8 bytes, the code works even with older Perl 5 versions.
+to UTF-8 bytes and back, the code works even with older Perl 5 versions.
 
     # ISO 8859-1 to UTF-8
     s/([\x80-\xFF])/chr(0xC0|ord($1)>>6).chr(0x80|ord($1)&0x3F)/eg;