Perl 字符串操作 以及 自定义排序

#!/usr/bin/perl -w
#########################################################################
# File Name: test6.pl
# Author: kevin xiang
# Created Time: 2014年07月10日 星期四 09时46分37秒
#########################################################################

#index(str,substr,position)，在大字符串中查找
#position可以设置起始位置，返回位置数
my $stuff = "hello word";
my $where = index($stuff,"wor");
print "where: $wheren";

my $where1 = index($stuff,"w");
print "where1: $where1n";

my $where2 = index($stuff,"w",6);
print "where2: $where2n";

# substr($string,$init_position,$length) 处理部分字符串
$substr1 = substr("hello world",6,5); #得到substr1: world
print "substr1: $substr1n";
#可以作替换字符串使用
substr($substr1,0)="hello ";
print "substr1: $substr1n"; #substr1: hello world
#替换功能也可以使用第四个参数
$string = "hello world";
substr($string,5,"xxxxx");
print "string: $stringn";

#sprintf 格式化数据 
$year = "2014";
$month = 8;
$day = 2.0;
$data_tag = sprintf("%s/%d/%.3f",$year,$month,$day);
print "data_tag: $data_tagn"; #data_tag: 2014/8/2.000

#排序
#排序子函数,按数字排序
sub by_num{
    $a <=> $b
}
@nums = (1,4,22,33,10,12);
print "nums: @numsn";
@result1 = sort @nums;
print "result1: @result1n"; #只会把数字当作字符排序
@result2 = sort by_num @nums;
print "result2: @result2n"; #会根据数值大小进行排序

#对hash排序
my %socre = (
    "kevin" => 100,"xiang" => 50,"jie" => 150,"xxx" => 1,"yyy" => 50
);
@socre1 = %socre;
print "socre1: @socre1n"; #socre1: xiang 50 jie 150 kevin 100 xxx 1 yyy 50

#排序子函数，根据value 从小到大 
#如果是数字直接用 <=> 如果是字符串用 cmp
sub by_socre_value{
    $socre{$a} <=> $socre{$b}
}
@socre2 = sort by_socre_value keys %socre;
print "socre2: @socre2n"; #socre2: xxx xiang yyy kevin jie


%socre = (
    "kevin" => 100,"yyy" => 50
);
#根据value 从小到大,如果value相同，则根据key字母反序
#如果还有很多个条件，可以加or再限制
sub by_socre_value_and_key{
    $socre{$a} <=> $socre{$b}
    or
    $b cmp $a;
}
@socre3 = sort by_socre_value_and_key keys %socre;
print "socre3: @socre3n"; #socre3: xxx yyy xiang kevin jie