CS-Notes/docs/_style/prism-master/examples/prism-perl.html
2018-12-19 14:09:39 +08:00

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<h2>Comments</h2>
<pre><code># Single line comment
=head1 Here There
Be Pods!
=cut</code></pre>
<h2>Strings</h2>
<pre><code>q/foo bar baz/;
q awhy not ?a;
qw(foo bar baz) q{foo bar baz}
q[foo bar baz] qq&lt;foo bar baz>
"foo bar baz" 'foo bar baz' `foo bar baz`</code></pre>
<h2>Regex</h2>
<pre><code>m/foo/ s/foo/bar/
m zfooz s zfoozbarz
qr(foo) m{foo} s(foo)(bar) s{foo}{bar}
m[foo] m&lt;foo> tr[foo][bar] s&lt;foo>&lt;bar>
/foo/i
</code></pre>
<h2>Variables</h2>
<pre><code>${^POSTMATCH}
$^V
$element_count = scalar(@whatever);
keys(%users) = 1000;
$1, $_, %!;</code></pre>
<h2>Numbers</h2>
<pre><code>12345
12345.67
.23E-10 # a very small number
3.14_15_92 # a very important number
4_294_967_296 # underscore for legibility
0xff # hex
0xdead_beef # more hex
0377 # octal (only numbers, begins with 0)
0b011011 # binary</code></pre>
<h2>Full example</h2>
<pre><code>sub read_config_file {
my ($class, $filename) = @_;
unless (defined $filename) {
my $home = File::HomeDir->my_home || '.';
$filename = File::Spec->catfile($home, '.pause');
return {} unless -e $filename and -r _;
}
my %conf;
if ( eval { require Config::Identity } ) {
%conf = Config::Identity->load($filename);
$conf{user} = delete $conf{username} unless $conf{user};
}
else { # Process .pause manually
open my $pauserc, '<', $filename
or die "can't open $filename for reading: $!";
while (<$pauserc>) {
chomp;
next unless $_ and $_ !~ /^\s*#/;
my ($k, $v) = /^\s*(\w+)\s+(.+)$/;
Carp::croak "multiple enties for $k" if $conf{$k};
$conf{$k} = $v;
}
}
return \%conf;
}</code></pre>