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For ddd2.pl
  Run on Tue May 25 16:52:24 2010
Reported on Tue May 25 16:56:46 2010

File /usr/local/lib/perl5/5.8.8/bytes.pm
Statements Executed 16
Statement Execution Time 361µs
Subroutines — ordered by exclusive time
Calls P F Exclusive
Time
Inclusive
Time
Subroutine
131313189µs189µsbytes::::importbytes::import
0000s0sbytes::::AUTOLOADbytes::AUTOLOAD
0000s0sbytes::::unimportbytes::unimport
Call graph for these subroutines as a Graphviz dot language file.
Line State
ments
Time
on line
Calls Time
in subs
Code
1package bytes;
2
316µsour $VERSION = '1.02';
4
515µs$bytes::hint_bits = 0x00000008;
6
7
# spent 189µs within bytes::import which was called 13 times, avg 15µs/call: # once (17µs+0s) by Net::HTTP::Methods::zlib_ok at line 18 of IO/Compress/Base.pm # once (16µs+0s) by Net::HTTP::Methods::zlib_ok at line 5 of IO/Compress/Base/Common.pm # once (15µs+0s) by Net::HTTP::Methods::zlib_ok at line 5 of IO/Compress/Adapter/Deflate.pm # once (15µs+0s) by Net::HTTP::Methods::zlib_ok at line 5 of IO/Uncompress/Adapter/Inflate.pm # once (15µs+0s) by Net::HTTP::Methods::zlib_ok at line 5 of IO/Compress/Gzip/Constants.pm # once (14µs+0s) by Net::HTTP::Methods::zlib_ok at line 13 of Compress/Raw/Zlib.pm # once (14µs+0s) by Net::HTTP::Methods::zlib_ok at line 6 of IO/Uncompress/RawInflate.pm # once (14µs+0s) by Net::HTTP::Methods::zlib_ok at line 8 of IO/Compress/Gzip.pm # once (14µs+0s) by Net::HTTP::Methods::zlib_ok at line 6 of IO/Uncompress/Base.pm # once (14µs+0s) by Net::HTTP::Methods::zlib_ok at line 7 of IO/Compress/RawDeflate.pm # once (14µs+0s) by Net::HTTP::Methods::zlib_ok at line 10 of IO/Uncompress/Gunzip.pm # once (14µs+0s) by Net::HTTP::Methods::zlib_ok at line 18 of Compress/Zlib.pm # once (13µs+0s) by Net::HTTP::Methods::zlib_ok at line 7 of IO/Compress/Zlib/Extra.pm
sub import {
813338µs $^H |= $bytes::hint_bits;
9}
10
11sub unimport {
12 $^H &= ~$bytes::hint_bits;
13}
14
15sub AUTOLOAD {
16 require "bytes_heavy.pl";
17 goto &$AUTOLOAD if defined &$AUTOLOAD;
18 require Carp;
19 Carp::croak("Undefined subroutine $AUTOLOAD called");
20}
21
22sub length ($);
23sub chr ($);
24sub ord ($);
25sub substr ($$;$$);
26sub index ($$;$);
27sub rindex ($$;$);
28
29112µs1;
30__END__
31
32=head1 NAME
33
34bytes - Perl pragma to force byte semantics rather than character semantics
35
36=head1 SYNOPSIS
37
38 use bytes;
39 ... chr(...); # or bytes::chr
40 ... index(...); # or bytes::index
41 ... length(...); # or bytes::length
42 ... ord(...); # or bytes::ord
43 ... rindex(...); # or bytes::rindex
44 ... substr(...); # or bytes::substr
45 no bytes;
46
47
48=head1 DESCRIPTION
49
50The C<use bytes> pragma disables character semantics for the rest of the
51lexical scope in which it appears. C<no bytes> can be used to reverse
52the effect of C<use bytes> within the current lexical scope.
53
54Perl normally assumes character semantics in the presence of character
55data (i.e. data that has come from a source that has been marked as
56being of a particular character encoding). When C<use bytes> is in
57effect, the encoding is temporarily ignored, and each string is treated
58as a series of bytes.
59
60As an example, when Perl sees C<$x = chr(400)>, it encodes the character
61in UTF-8 and stores it in $x. Then it is marked as character data, so,
62for instance, C<length $x> returns C<1>. However, in the scope of the
63C<bytes> pragma, $x is treated as a series of bytes - the bytes that make
64up the UTF8 encoding - and C<length $x> returns C<2>:
65
66 $x = chr(400);
67 print "Length is ", length $x, "\n"; # "Length is 1"
68 printf "Contents are %vd\n", $x; # "Contents are 400"
69 {
70 use bytes; # or "require bytes; bytes::length()"
71 print "Length is ", length $x, "\n"; # "Length is 2"
72 printf "Contents are %vd\n", $x; # "Contents are 198.144"
73 }
74
75chr(), ord(), substr(), index() and rindex() behave similarly.
76
77For more on the implications and differences between character
78semantics and byte semantics, see L<perluniintro> and L<perlunicode>.
79
80=head1 LIMITATIONS
81
82bytes::substr() does not work as an lvalue().
83
84=head1 SEE ALSO
85
86L<perluniintro>, L<perlunicode>, L<utf8>
87
88=cut