的Perl：返回執行給調用者，但隨後再次醒來

Question

假設，我們有一個bash腳本：

#!/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"; 

我怎麼能這樣？

Answer 1

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

#!/usr/bin/perl 
... 

- 或 -

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

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