diff options
Diffstat (limited to 'contrib/perl5/lib/bytes.pm')
| -rw-r--r-- | contrib/perl5/lib/bytes.pm | 27 |
1 files changed, 22 insertions, 5 deletions
diff --git a/contrib/perl5/lib/bytes.pm b/contrib/perl5/lib/bytes.pm index f93d615..f2f7e01 100644 --- a/contrib/perl5/lib/bytes.pm +++ b/contrib/perl5/lib/bytes.pm @@ -38,11 +38,28 @@ The C<use bytes> pragma disables character semantics for the rest of the lexical scope in which it appears. C<no bytes> can be used to reverse the effect of C<use bytes> within the current lexical scope. -Perl normally assumes character semantics in the presence of -character data (i.e. data that has come from a source that has -been marked as being of a particular character encoding). - -To understand the implications and differences between character +Perl normally assumes character semantics in the presence of character +data (i.e. data that has come from a source that has been marked as +being of a particular character encoding). When C<use bytes> is in +effect, the encoding is temporarily ignored, and each string is treated +as a series of bytes. + +As an example, when Perl sees C<$x = chr(400)>, it encodes the character +in UTF8 and stores it in $x. Then it is marked as character data, so, +for instance, C<length $x> returns C<1>. However, in the scope of the +C<bytes> pragma, $x is treated as a series of bytes - the bytes that make +up the UTF8 encoding - and C<length $x> returns C<2>: + + $x = chr(400); + print "Length is ", length $x, "\n"; # "Length is 1" + printf "Contents are %vd\n", $x; # "Contents are 400" + { + use bytes; + print "Length is ", length $x, "\n"; # "Length is 2" + printf "Contents are %vd\n", $x; # "Contents are 198.144" + } + +For more on the implications and differences between character semantics and byte semantics, see L<perlunicode>. =head1 SEE ALSO |
