| File | /opt/wise/lib/perl5/5.10.0/bytes.pm | Statements Executed | 17 | Total Time | 4.1e-05 seconds |
| Calls | P | F | Exclusive Time |
Inclusive Time |
Subroutine | |
|---|---|---|---|---|---|---|
| 14 | 14 | 14 | 0.00010 | 0.00010 | bytes:: | import |
| 0 | 0 | 0 | 0 | 0 | bytes:: | AUTOLOAD |
| 0 | 0 | 0 | 0 | 0 | bytes:: | unimport |
| Line | Stmts. | Exclusive Time | Avg. | Code |
|---|---|---|---|---|
| 1 | package bytes; | |||
| 2 | ||||
| 3 | 1 | 0 | 0 | our $VERSION = '1.03'; |
| 4 | ||||
| 5 | 1 | 1.0e-6 | 1.0e-6 | $bytes::hint_bits = 0x00000008; |
| 6 | ||||
| 7 | # spent 104µs within bytes::import which was called 14 times, avg 7µs/call:
# once (13µs+0) at line 5 of /opt/wise/lib/perl5/5.10.0/x86_64-linux-thread-multi/IO/Compress/Base/Common.pm
# once (9µs+0) by Data::Dumper::BEGIN or Data::Dumper::qquote at line 663 of /opt/wise/lib/perl5/5.10.0/x86_64-linux-thread-multi/Data/Dumper.pm
# once (8µs+0) at line 18 of /opt/wise/lib/perl5/5.10.0/x86_64-linux-thread-multi/IO/Compress/Base.pm
# once (8µs+0) at line 8 of /opt/wise/lib/perl5/5.10.0/x86_64-linux-thread-multi/IO/Compress/Gzip.pm
# once (7µs+0) at line 13 of /opt/wise/lib/perl5/5.10.0/x86_64-linux-thread-multi/Compress/Raw/Zlib.pm
# once (7µs+0) at line 18 of /opt/wise/lib/perl5/5.10.0/x86_64-linux-thread-multi/Compress/Zlib.pm
# once (7µs+0) at line 10 of /opt/wise/lib/perl5/5.10.0/x86_64-linux-thread-multi/IO/Uncompress/Gunzip.pm
# once (7µs+0) at line 7 of /opt/wise/lib/perl5/5.10.0/x86_64-linux-thread-multi/IO/Compress/RawDeflate.pm
# once (7µs+0) at line 5 of /opt/wise/lib/perl5/5.10.0/x86_64-linux-thread-multi/IO/Compress/Gzip/Constants.pm
# once (7µs+0) at line 5 of /opt/wise/lib/perl5/5.10.0/x86_64-linux-thread-multi/IO/Uncompress/Adapter/Inflate.pm
# once (6µs+0) at line 6 of /opt/wise/lib/perl5/5.10.0/x86_64-linux-thread-multi/IO/Uncompress/Base.pm
# once (6µs+0) at line 6 of /opt/wise/lib/perl5/5.10.0/x86_64-linux-thread-multi/IO/Uncompress/RawInflate.pm
# once (6µs+0) at line 5 of /opt/wise/lib/perl5/5.10.0/x86_64-linux-thread-multi/IO/Compress/Adapter/Deflate.pm
# once (6µs+0) at line 7 of /opt/wise/lib/perl5/5.10.0/x86_64-linux-thread-multi/IO/Compress/Zlib/Extra.pm | |||
| 8 | 14 | 3.6e-5 | 2.6e-6 | $^H |= $bytes::hint_bits; |
| 9 | } | |||
| 10 | ||||
| 11 | sub unimport { | |||
| 12 | $^H &= ~$bytes::hint_bits; | |||
| 13 | } | |||
| 14 | ||||
| 15 | sub AUTOLOAD { | |||
| 16 | require "bytes_heavy.pl"; | |||
| 17 | goto &$AUTOLOAD if defined &$AUTOLOAD; | |||
| 18 | require Carp; | |||
| 19 | Carp::croak("Undefined subroutine $AUTOLOAD called"); | |||
| 20 | } | |||
| 21 | ||||
| 22 | sub length (_); | |||
| 23 | sub chr (_); | |||
| 24 | sub ord (_); | |||
| 25 | sub substr ($$;$$); | |||
| 26 | sub index ($$;$); | |||
| 27 | sub rindex ($$;$); | |||
| 28 | ||||
| 29 | 1 | 4.0e-6 | 4.0e-6 | 1; |
| 30 | __END__ | |||
| 31 | ||||
| 32 | =head1 NAME | |||
| 33 | ||||
| 34 | bytes - Perl pragma to force byte semantics rather than character semantics | |||
| 35 | ||||
| 36 | =head1 SYNOPSIS | |||
| 37 | ||||
| 38 | use bytes; | |||
| 39 | ... chr(...); # or bytes::chr | |||
| 40 | ... index(...); # or bytes::index | |||
| 41 | ... length(...); # or bytes::length | |||
| 42 | ... ord(...); # or bytes::ord | |||
| 43 | ... rindex(...); # or bytes::rindex | |||
| 44 | ... substr(...); # or bytes::substr | |||
| 45 | no bytes; | |||
| 46 | ||||
| 47 | ||||
| 48 | =head1 DESCRIPTION | |||
| 49 | ||||
| 50 | The C<use bytes> pragma disables character semantics for the rest of the | |||
| 51 | lexical scope in which it appears. C<no bytes> can be used to reverse | |||
| 52 | the effect of C<use bytes> within the current lexical scope. | |||
| 53 | ||||
| 54 | Perl normally assumes character semantics in the presence of character | |||
| 55 | data (i.e. data that has come from a source that has been marked as | |||
| 56 | being of a particular character encoding). When C<use bytes> is in | |||
| 57 | effect, the encoding is temporarily ignored, and each string is treated | |||
| 58 | as a series of bytes. | |||
| 59 | ||||
| 60 | As an example, when Perl sees C<$x = chr(400)>, it encodes the character | |||
| 61 | in UTF-8 and stores it in $x. Then it is marked as character data, so, | |||
| 62 | for instance, C<length $x> returns C<1>. However, in the scope of the | |||
| 63 | C<bytes> pragma, $x is treated as a series of bytes - the bytes that make | |||
| 64 | up 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 | ||||
| 75 | chr(), ord(), substr(), index() and rindex() behave similarly. | |||
| 76 | ||||
| 77 | For more on the implications and differences between character | |||
| 78 | semantics and byte semantics, see L<perluniintro> and L<perlunicode>. | |||
| 79 | ||||
| 80 | =head1 LIMITATIONS | |||
| 81 | ||||
| 82 | bytes::substr() does not work as an lvalue(). | |||
| 83 | ||||
| 84 | =head1 SEE ALSO | |||
| 85 | ||||
| 86 | L<perluniintro>, L<perlunicode>, L<utf8> | |||
| 87 | ||||
| 88 | =cut |