Perl笔记
来自Jack's Lab
(版本间的差异)
| 第4行: | 第4行: | ||
$ apt-get install perl perl-modules libcatalyst-perl libcatalyst-modules-perl | $ apt-get install perl perl-modules libcatalyst-perl libcatalyst-modules-perl | ||
</pre> | </pre> | ||
| + | |||
| + | <br><br> | ||
| + | |||
| + | == 位反转 == | ||
| + | |||
| + | <source lang=perl> | ||
| + | $ cat bit-rev.pl | ||
| + | #!/usr/bin/perl | ||
| + | |||
| + | sub rev | ||
| + | { | ||
| + | my $in = shift; | ||
| + | $in = ($in & 0x55555555) << 1 | ($in & 0xaaaaaaaa) >> 1; | ||
| + | $in = ($in & 0x33333333) << 2 | ($in & 0xCCCCCCCC) >> 2; | ||
| + | $in = ($in & 0x0f0f0f0f) << 4 | ($in & 0xf0f0f0f0) >> 4; | ||
| + | $in = ($in & 0x00ff00ff) << 8 | ($in & 0xff00ff00) >> 8; | ||
| + | $in = ($in & 0x0000ffff) << 16 | ($in & 0xffff0000) >> 16; | ||
| + | return $in; | ||
| + | } | ||
| + | |||
| + | my $d = 0x80008001; | ||
| + | printf "d = 0x%08x\n", $d; | ||
| + | |||
| + | $ ./bit-rev.pl | ||
| + | d = 0x80008001 | ||
| + | rd = 0x80010001 | ||
| + | </source> | ||
<br><br> | <br><br> | ||
2014年12月25日 (四) 08:26的版本
1 Catalyst 安装
$ apt-get install perl perl-modules libcatalyst-perl libcatalyst-modules-perl
2 位反转
$ cat bit-rev.pl
#!/usr/bin/perl
sub rev
{
my $in = shift;
$in = ($in & 0x55555555) << 1 | ($in & 0xaaaaaaaa) >> 1;
$in = ($in & 0x33333333) << 2 | ($in & 0xCCCCCCCC) >> 2;
$in = ($in & 0x0f0f0f0f) << 4 | ($in & 0xf0f0f0f0) >> 4;
$in = ($in & 0x00ff00ff) << 8 | ($in & 0xff00ff00) >> 8;
$in = ($in & 0x0000ffff) << 16 | ($in & 0xffff0000) >> 16;
return $in;
}
my $d = 0x80008001;
printf "d = 0x%08x\n", $d;
$ ./bit-rev.pl
d = 0x80008001
rd = 0x80010001
3 Resource
- Mastering Perl: http://chimera.labs.oreilly.com/books/1234000001527/index.html
- Catalyst Manual: https://metacpan.org/release/Catalyst-Manual
- meta cpan: https://metacpan.org/pod/Data::Random
- perl doc: http://perldoc.perl.org/