Perl：将执行返回给调用者，然后再次唤醒

Question

假设我们有一个bash脚本：

#!/bin/bash

perl /home/user/myscript.pl
echo "hello"

myscript.pl：

#!/usr/bin/perl

print "First\n";
#here I want the script to sleep for 5 seconds
#and return the execution back to the caller
#so, "hello" will be printed
#but after 5 seconds the script will wake up from sleep and run the next line

print "Second\n";

我怎么能这样？

Answer 1

#!/bin/bash
perl /home/user/myscript.pl &
sleep 5
echo "hello"

#!/usr/bin/perl
...

-OR -

#!/bin/bash
perl /home/user/myscript.pl
echo "hello"

#!/usr/bin/perl
sleep(5);
$SIG{CHLD} = 'IGNORE';
exit(0) if fork();
...