perl小程序(一）

?1 ?请用perl在屏幕输出hello,world

[root@localhost?perl]#?cat?perlhello.pl?
#!/usr/bin/perl
print?"hello,world!n";
[root@localhost?perl]#?./perlhello.pl?
hello,world!

2 ?截取出正则的匹配内容，在shell中，真是头都大了

#!/usr/bin/perl?-w
$_="<span?class="title">Counter-Strike?Global?Ofensive</span>";
if(/<span?class="title">(.*)</span>/)
{
print?"$1n";
}

[root@localhost?perl]#?./perlre.pl?
Counter-Strike?Global?Ofensive

稍微改动下，截取括号的内容，也是很简单

#!/usr/bin/perl -w?

#注意每一句以分号结尾，注意是否转义

$_="(Counter-Strike?Global?Ofensive)";
if(/((.*))/)
{
print?"$1n";
}

3 ?接受标准输入，并输出

#!/usr/bin/perl?-w
while?(<>)
{print;}

[root@localhost perl]# ./receive.pl?

hello,i am liuliancao

hello,i am liuliancao

4 计算圆的面积

#!/usr/bin/perl?-w
print?"please?input?the?radius?of?the?circle";
$r=<STDIN>;
if($r?lt?0)
{$c=0;}
else
{$c=2*$r*3.141592654;}
print?"the?c?is?$cn";

[root@localhost?perl]#?./circle.pl?
please?input?the?radius?of?the?circle:1??
the?c?is?6.283185308

5 计算两个数的乘积，并输出它们

#!/usr/bin/perl?-w
print?"please?input?two?number?divided?by?Enter,and?i?will?mutiply?themn";
chomp($a=<STDIN>);
$b=<STDIN>;
print?"a?is?$a,?and?b?is?$b?and??the?muti?result?is?",$a*$b,"?!n";

[root@localhost perl]# ./muti.pl?

please input two number divided by Enter,and i will mutiply them

2

5

a is 2,and b is 5

?and ?the muti result is 10 !

6 重复输出指定次数字符串

#!/usr/bin/perl?-w
print?"please?input?string?and?times?divided?by?Enter!n";
chomp?($a=<STDIN>);
$b=<STDIN>;
$result=$a?x?$b;
print?"result?is?$resultn";

[root@localhost?perl]#?./stringtimes.pl?
please?input?string?and?times?divided?by?Enter!
liuliancao
5
result?is?liuliancaoliuliancaoliuliancaoliuliancaoliuliancao