=encoding euc-jp =head1 NAME =begin original bytes - Perl pragma to force byte semantics rather than character semantics =end original bytes - 文字単位ではなくバイト単位の意味論を強制する Perl プラグマ =head1 SYNOPSIS use bytes; ... chr(...); # or bytes::chr ... index(...); # or bytes::index ... length(...); # or bytes::length ... ord(...); # or bytes::ord ... rindex(...); # or bytes::rindex ... substr(...); # or bytes::substr no bytes; =head1 DESCRIPTION =begin original The C pragma disables character semantics for the rest of the lexical scope in which it appears. C can be used to reverse the effect of C within the current lexical scope. =end original The C pragma disables character semantics for the rest of the lexical scope in which it appears. C can be used to reverse the effect of C within the current lexical scope. (TBT) =begin original 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 is in effect, the encoding is temporarily ignored, and each string is treated as a series of bytes. =end original 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 is in effect, the encoding is temporarily ignored, and each string is treated as a series of bytes. (TBT) =begin original As an example, when Perl sees C<$x = chr(400)>, it encodes the character in UTF-8 and stores it in $x. Then it is marked as character data, so, for instance, C returns C<1>. However, in the scope of the C pragma, $x is treated as a series of bytes - the bytes that make up the UTF8 encoding - and C returns C<2>: =end original As an example, when Perl sees C<$x = chr(400)>, it encodes the character in UTF-8 and stores it in $x. Then it is marked as character data, so, for instance, C returns C<1>. However, in the scope of the C pragma, $x is treated as a series of bytes - the bytes that make up the UTF8 encoding - and C returns C<2>: (TBT) $x = chr(400); print "Length is ", length $x, "\n"; # "Length is 1" printf "Contents are %vd\n", $x; # "Contents are 400" { use bytes; # or "require bytes; bytes::length()" print "Length is ", length $x, "\n"; # "Length is 2" printf "Contents are %vd\n", $x; # "Contents are 198.144" } =begin original chr(), ord(), substr(), index() and rindex() behave similarly. =end original chr(), ord(), substr(), index() and rindex() behave similarly. (TBT) =begin original For more on the implications and differences between character semantics and byte semantics, see L and L. =end original For more on the implications and differences between character semantics and byte semantics, see L and L. (TBT) =head1 LIMITATIONS (制限) =begin original bytes::substr() does not work as an lvalue(). =end original bytes::substr() は lvalue() では動作しません。 =head1 SEE ALSO L, L, L =cut