perl回调函数

在计算机程序设计中&＃xff0c;回调函数&＃xff0c;或简称回调&＃xff08;Callback&＃xff09;&＃xff0c;是指通过函数参数传递到其它代码的&＃xff0c;某一块可执行代码的引用。这一设计允许了底层代码调用在高层定义的子程序。没啥不好理解的呀&＃xff0c;就是向函数的参数为 一个函数的引用呀。。[root&＃64;wx03 ~]# cat a2.pl
use AE;use AnyEvent;
##定义watchsub run {my $code&＃61;shift;my $t &＃61; AnyEvent->timer(after &＃61;> 0,interval &＃61;> 1,cb &＃61;> $code,);
my $cv &＃61; AnyEvent->condvar;$cv->recv;};sub test {
print "11111111111\n";
};run(sub {test()});
[root&＃64;wx03 ~]# perl a2.pl
11111111111
11111111111[root&＃64;wx03 ~]# cat a2.pl
use AE;use AnyEvent;
##定义watchsub run {my $code&＃61;shift;my $t &＃61; AnyEvent->timer(after &＃61;> 0,interval &＃61;> 1,cb &＃61;> $code,);
my $cv &＃61; AnyEvent->condvar;$cv->recv;};sub test {
print "11111111111\n";
};run(\&test);
[root&＃64;wx03 ~]# perl a2.pl
11111111111
11111111111[root&＃64;wx03 ~]# perl a2.pl
11111111111
1: callback must be a CODE reference or another callable object at /usr/local/perl/lib/site_perl/5.22.1/x86_64-linux/AnyEvent/Impl/EV.pm line 50.
[root&＃64;wx03 ~]# cat a2.pl
use AE;use AnyEvent;
##定义watchsub run {my $code&＃61;shift;my $t &＃61; AnyEvent->timer(after &＃61;> 0,interval &＃61;> 1,cb &＃61;> $code,);
my $cv &＃61; AnyEvent->condvar;$cv->recv;};sub test {
print "11111111111\n";
};run(&test);
[root&＃64;wx03 ~]# perl a2.pl
11111111111
1: callback must be a CODE reference or another callable object at /usr/local/perl/lib/site_perl/5.22.1/x86_64-linux/AnyEvent/Impl/EV.pm line 50.