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Perl 函数返回值的问题

发布时间:2020-12-15 23:47:19 所属栏目:大数据 来源:网络整理
导读:[root@jhoa 2015]# cat ping_dns.pl use HTTP::Date qw(time2iso str2time time2iso time2isoz);use Net::Ping; my @array=( "mbank.app.cz" ); while (1==1){ my $CurrTime = time2iso(time()); foreach $host (@array){ $p = Net::Ping-new("icmp"); open
[root@jhoa 2015]# cat ping_dns.pl 
use HTTP::Date qw(time2iso str2time time2iso time2isoz);
use Net::Ping;  
my @array=( "mbank.app.cz"
             ); 
while (1==1){  
my $CurrTime = time2iso(time());  
        foreach $host (@array){  
        $p = Net::Ping->new("icmp");  
  
         open (A,">>ping.log");  
        (  
print A ("$CurrTime---$host is active.n") 
 
)  if $p->ping($host,5);  
  
       open (B,">>ping.log");  
       (   
print B ("$CurrTime---$host is lost.n"),print "xxxxxxn" 
)  unless $p->ping($host,5);  
        
   $p->close();  
 sleep(5)      
}}  


[root@jhoa 2015]# perl ping_dns.pl 
xxxxxx
xxxxxx
xxxxxx
xxxxxx


1[root@jhoa 2015]# tail -10 ping.log 
12015-02-26 11:48:58---mbank.app.cz is lost.
12015-02-26 11:49:03---mbank.app.cz is lost.
12015-02-26 12:23:36---mbank.app.cz is lost.
12015-02-26 12:23:41---mbank.app.cz is lost.
12015-02-26 12:23:46---mbank.app.cz is lost.
12015-02-26 12:24:11---mbank.app.cz is lost.
12015-02-26 12:24:16---mbank.app.cz is lost.
12015-02-26 12:24:21---mbank.app.cz is lost.
12015-02-26 12:24:26---mbank.app.cz is lost.


为啥前面会打印出1呢? 因为1是print 的返回值

[root@jhoa 2015]# cat a3.pl 
(print "a",print "b");
[root@jhoa 2015]# perl a3.pl 
ba1[root@jhoa 2015]#


[root@jhoa 2015]# cat a3.pl 
(print "a","b");
[root@jhoa 2015]# perl a3.pl 
ab[root@jhoa 2015]# 

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