perl简单入门

#!/usr/bin/perl
$tmp1 = 1;
$tmp2 = $tmp1 + 1;
$tmp3 = $tmp2 * 2;
print "$tmp3 \n";
$tmp4 = "this";
$tmp5 = $tmp4 . $tmp3;
print "tmp5 is $tmp5\n";

print "hello world\n";
print "---- $tmp5 \n";
print $tmp5."\n";

while($tmp3 < 10)
{
       print "Current tmp3 is $tmp3\n";
       $tmp3 ++;
}

#chomp 读入去掉空格

$text1 = "this is input \n";
chomp($text1);
print $text1."\n";


$text2 = <STDIN>;
#含有换行
print "the use typed ---- $text2 \n";
chomp($text2);
print "the use typed ---- $text2 \n";

#  $ARGV[0,1,2,3]获取命令行参数内容
#  $#ARGV获取最后一个元素索引

if( $#ARGV != -1)
{
        print "has $#ARGV \n";
        for($i = 0;$i <= $#ARGV; $i ++)
        {
                $tmp = $i + 1;
                print "the $tmp is $ARGV[$i] \n";
        }
}

system("echo helloworld");

sub function
{
        $pm_n = $#_ + 1;
        if($pm_n == 1)
        {
                printf("return error\n");
                return "error";
        }
        print "the perameter num is $pm_n\n";
        print "the perameter is @_ \n";  #参数在一起
        print "the first perameter is @_[0] \n"; #参数1
        print "the second perameter is @_[1] \n"; #参数2
        return 0;
}

$result = function(1);
print "---the first call of function is $result \n";
$result = function(2,3);
print "---the second call of function is $result \n";
$pa = "hello";
$pb = "world";
$result = function($pa,$pb);
print "+++the third call of function is $result \n";