Perl 代码片段记录

1、Perl 调用环境中的命令， 如linux 命令，windows 的cmd ?命令等，此处使用简单的反引号调用，可以捕捉命令的输出，且每次输出都带一个回车换行:

 #!/usr/bin/perl
 
 use strict;

 sub main {
 
     foreach (@INC) {
         print "$_ : ".`ls $_`;  # call ls command!
     }
 
 } 
 
 &main ();

2、 函数 localtime (),返回本地时间的各项时间数据的列表， （seconds,minutes,hours,day of month,month,year,day of week,day of year,daylight savings time）

use strict;
use warnings;
use POSIx;

my ($sec,$min,$hour,$mday,$mon,$year,$wday,$yday,$isdst) =
	localtime (); # list context
my $now = scalar (localtime); # scalar context

$year += 1900;
$mon += 1;

使用到的模块：File::Log????? Net::Ping

#!perl

# author : ez
# date : 2015/3/5
# describe : test the host reachable and print 
# 			the none reachable time;

use strict;
use warnings;
use Net::Ping;
use File::Log;

package Main;

# global
my $host = "127.0.0.1"; # the remote host
my $proto = "icmp";     # protocol to ping
my $logfile = "./log.txt";   # log file name
my $file = undef;   # log file handle
my $pn = undef;     # ping entity


sub _init_log_file {
	$file = File::Log -> new ({
		debug 		=> 4,logFileName => $logfile,logFileMode => ">>",dateTimeStamp => 1,stderrRedirect => 1,defaultFile => 1,logFileDateTime => 0,appName => "reachable.pl",PIDstamp => 0,storeExpText => 1,msgprepend => '',say => 1
	});
	return $file if $file;
	undef;
}

sub main {
	$pn = Net::Ping -> new ($proto);
	$file = &_init_log_file;
	die "i cannot open log file or init ping entityrn" 
		unless ($file || $pn);
	while (1) {
		if (! ($pn -> ping ($host,2))) {
			$file -> msg (2,"$host is not alive.");
		}
	}
}

END {
	$file -> close () if $file;
	$pn -> close () if $pn;
}

&main;

4、 perl here document： 从标记声明的下一行开始，一直到遇到标记为止的所有字符串，赋值给变量：

#! perl

use strict;
use warnings;

my $a = 100;
my $b = 20;
my $str = <<__end
	hello $a;
	hello $b;
	this is @INC;
__end
;
print $str;

5、 Strawberry Perl 在windows 7 输出中文：

#! perl

use strict;
use warnings;
use v5.14;
use utf8;
# use Encode qw(encode decode);
# use encoding "utf8",STDOUT => 'gbk';

sub test_chinese  {
	my $gb2312_str = "中国";
	binmode (STDOUT,':encoding(gbk)');
	print $gb2312_str;
}

&test_chinese;