Upgrade to Tie::File 0.21.

[p5sagit/p5-mst-13.2.git] / lib / encoding.pm

diff --git a/lib/encoding.pm b/lib/encoding.pm
index 642726d..441be33 100644 (file)
--- a/lib/encoding.pm
+++ b/lib/encoding.pm
@@ -4,6 +4,13 @@ our $VERSION = '1.00';
 
 use Encode;
 
+BEGIN {
+    if (ord("A") == 193) {
+       require Carp;
+       Carp::croak "encoding pragma does not support EBCDIC platforms";
+    }
+}
+
 sub import {
     my ($class, $name) = @_;
     $name = $ENV{PERL_ENCODING} if @_ < 2;
@@ -45,10 +52,15 @@ encoding - pragma to control the conversion of legacy data into Unicode
 
     print "tera\n" if ord(pack("C", 0xdf)) == 0x3af;
 
-    # but pack/unpack are not affected, in case you still
+    # ... as are eq and cmp ...
+
+    print "peta\n" if "\x{3af}" eq  pack("C", 0xdf);
+    print "exa\n"  if "\x{3af}" cmp pack("C", 0xdf) == 0;
+
+    # ... but pack/unpack C are not affected, in case you still
     # want back to your native encoding
 
-    print "peta\n" if unpack("C", (pack("C", 0xdf))) == 0xdf;
+    print "zetta\n" if unpack("C", (pack("C", 0xdf))) == 0xdf;
 
 =head1 DESCRIPTION
 
@@ -88,12 +100,19 @@ If no encoding is specified, the environment variable L<PERL_ENCODING>
 is consulted.  If that fails, "latin1" (ISO 8859-1) is assumed.  If no
 encoding can be found, C<Unknown encoding '...'> error will be thrown.
 
+Note if you want to get back to the original byte encoding, you need
+to use things like I/O with encoding discplines (see L<open>) or the
+Encode module, since C<no encoding> (or re-C<encoding>) do not work.
+
 =head1 KNOWN PROBLEMS
 
 For native multibyte encodings (either fixed or variable length)
 the current implementation of the regular expressions may introduce
 recoding errors for longer regular expression literals than 127 bytes.
 
+The encoding pragma is not supported on EBCDIC platforms.
+(Porters wanted.)
+
 =head1 SEE ALSO
 
 L<perlunicode>, L<Encode>