perl 的几个常用的基础函数

努力小伙

1. #!/usr/bin/perl -w
   
2. use strict;
   
3. 
   
4. my $decimal = hex("af"); #十六进制转换为十进制
   
5. print "$decimal\n";
   
6. 
   
7. my $rand_num = rand(4); #求0-4以内的随机数
   
8. print "$rand_num\n";
   
9. 
   
10. my $rand_int = int(rand(4)); #0-4之间的随机整数
    
11. print "$rand_int\n";
    
12. 
    
13. my ($sec,$min,$hour,$mday,$mon,
    
14.    $year,$wday,$yday,$isdist) = localtime(time); #localtime（time）
    
15.                         #返回9个时间元素
    
16. print "$hour:$min:$sec\n";
    
17. 
    
18. my @file_stat = stat("found.pl"); #返回12个值
    
19. print "@file_stat\n";
    
20. 
    
21. #数组--grep函数
    
22. my @array = qw("google" "domain" "hello" "pen");
    
23. print "@array\n";
    
24. 
    
25. my @filter = grep(/o/,@array);
    
26. print "@filter\n";
    
27. 
    
28. #数组
    
29. (my $first_elem) = @filter; #把数组的第一个元素赋值给变量
    
30. print "$first_elem\n";
    
31. 
    
32. #哈希表--delete
    
33. my %hash = (
    
34.     name    => "Tou",
    
35.     age    => "24",
    
36.     address    => "GuangZhou"
    
37. );
    
38. #删除key为name的元素
    
39. delete $hash{"name"};
    
40. 
    
41. foreach (keys %hash){
    
42.     
    
43.     my $value = $hash{$_};
    
44.     print "$_ => $value\n";
    
45. }
    
46. 
    
47. #split函数
    
48. my $str = "China-Is-Greatful!";
    
49. my @splits = split(/-/,$str);
    
50. print "@splits\n";
    
51. 
    
52. #reverse 函数，反转
    
53. my @rev = reverse(@splits);
    
54. print "@rev\n";
    
55. 
    
56. #sort 函数，排序
    
57. my @numbers = qw(1 3 2 34 21 0 2);
    
58. my @sort_num = (sort{$a <=> $b} @numbers);
    
59. print "@sort_num\n";
    
60. 
    
61. #length 函数，求长度
    
62. print length($str),"\n";
    
63. 
    
64. #substr 函数，抽提字串
    
65. print substr($str,2,4),"\n";
    
66. 
    
67. #index 函数，查找字符串第一次出现的位置
    
68. print index($str,"ea",5),"\n";
    
69. 
    
70. #join 函数，在数组元素之间加入指定字符串
    
71. print join(" <= ",@sort_num),"\n";