perl 的几个常用的基础函数

#!/usr/bin/perl -w
use strict;

my $decimal = hex("af");  #十六进制转换为十进制
print "$decimal\n";

my $rand_num = rand(4);  #求0-4以内的随机数
print "$rand_num\n";

my $rand_int = int(rand(4));  #0-4之间的随机整数
print "$rand_int\n";

my ($sec,$min,$hour,$mday,$mon,
   $year,$wday,$yday,$isdist) = localtime(time); #localtime（time）
                        #返回9个时间元素
print "$hour:$min:$sec\n";

my @file_stat = stat("found.pl"); #返回12个值
print "@file_stat\n";

#数组--grep函数
my @array = qw("google" "domain" "hello" "pen");
print "@array\n";

my @filter = grep(/o/,@array);
print "@filter\n";

#数组
(my $first_elem) = @filter; #把数组的第一个元素赋值给变量
print "$first_elem\n";

#哈希表--delete
my %hash = (
    name    => "Tou",
    age    => "24",
    address    => "GuangZhou"
);
#删除key为name的元素
delete $hash{"name"};

foreach (keys %hash){

    my $value = $hash{$_};
    print "$_ => $value\n";
}

#split函数
my $str = "China-Is-Greatful!";
my @splits = split(/-/,$str);
print "@splits\n";

#reverse 函数，反转
my @rev = reverse(@splits);
print "@rev\n";

#sort 函数，排序
my @numbers = qw(1 3 2 34 21 0 2);
my @sort_num = (sort{$a <=> $b} @numbers);
print "@sort_num\n";

#length 函数，求长度
print length($str),"\n";

#substr 函数，抽提字串
print substr($str,2,4),"\n";

#index 函数，查找字符串第一次出现的位置
print index($str,"ea",5),"\n";

#join 函数，在数组元素之间加入指定字符串
print join(" <= ",@sort_num),"\n";