Perl笔记

1 Catalyst 安装

$ apt-get install perl perl-modules libcatalyst-perl libcatalyst-modules-perl

2 32位位反转

$ 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", $d;
printf "rd = 0x%08x\n", &rev($d);

$ ./bit-rev.pl
d = 0x80008001
rd = 0x80010001

3 进制转换

For bash:

# for bash. your shell is probably different.

alias d2h="perl -e 'printf qq|%X\n|, int( shift )'"
alias d2o="perl -e 'printf qq|%o\n|, int( shift )'"
alias d2b="perl -e 'printf qq|%b\n|, int( shift )'"

alias h2d="perl -e 'printf qq|%d\n|, hex( shift )'"
alias h2o="perl -e 'printf qq|%o\n|, hex( shift )'"
alias h2b="perl -e 'printf qq|%b\n|, hex( shift )'"

alias o2h="perl -e 'printf qq|%X\n|, oct( shift )'"
alias o2d="perl -e 'printf qq|%d\n|, oct( shift )'"
alias o2b="perl -e 'printf qq|%b\n|, oct( shift )'"

4 十六进制字符串

$ cat test.pl
my $seed = 0x52536264;
print "seed = " . $seed . "\n";
printf "seed = 0x%x\n", $seed;

# bit revert
$seed = &rev($seed);
printf "seed bit revert = 0x%x\n", $seed;

my $id = sprintf("0x%08x", $seed);

printf "id = %s\n", $id;
printf "decode id = 0x%x\n", &rev(hex $id);

$ ./test.pl
seed = 1381196388
seed = 0x52536264
seed bit revert = 0x2646ca4a
id = 0x2646ca4a
decode id = 0x52536264

== 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/
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