Solve the timeout problem in the script [shell, perl, ssh]

Sometimes we execute a script, because some programs in the script are suspended and time-out, which affects our judgment on the next step. At will, it is necessary to set the timeout settings for functions and processes so that they can return a state after a period of no response.

 

In the command parameters, ssh-o ServerAliveInterval = 60 can be controlled to 60 seconds.

For example, if ClientAliveInterval = 15 and ClientAliveCountMax = 3, it will be sent once every 15 seconds, once every 30 seconds, and once every 45 seconds. If all three attempts fail, the link will be recalled.

However, this parameter is not easy to use. You can add sleep 100 next to it.

 

 
 

  
  
#!/bin/sh 
  
  
  
  
  
timeout() 
  
  
{ 
  
  
        waitfor=3 
  
  
        command=$* 
  
  
        $command & 
  
  
        commandpid=$! 
  
  
  
  
  
        ( sleep $waitfor ; kill -9 $commandpid > /dev/null 2>&1 ) & 
  
  
  
  
  
        watchdog=$! 
  
  
        sleeppid=$PPID 
  
  
        wait $commandpid > /dev/null 2>&1  
  
  
  
  
  
        kill $sleeppid > /dev/null 2>&1 
  
  
} 
  
  
  
  
  
test123() 
  
  
{ 
  
  
 
  
  
        ifconfig 
  
  
        sleep 10 
  
  
        ifconfig 
  
  
#        curl htpp://www.facebook.com 
  
  
} 
  
  
  
  
  
timeout test123 
 
 

 

650) this. width = 650; "border =" 0 "alt =" "src =" http://www.bkjia.com/uploads/allimg/131227/1T52a427-0.jpg "/>

 

Basically controlled to about 3 s

There is also a perl version

 
 

  
  
#! /Usr/bin/env perl
  
  
Use POSIX qw (strftime WNOHANG );
  
  
 
  
  
# Check input
  
  
My $ timeout = shift @ ARGV;
  
  
My ($ secs) = $ timeout = ~ /-- Timeout = (\ d +) $ /;
  
  
Unless ($ secs)
  
  
{
  
  
Print "Usage:./timeout -- timeout = [SECONDS] [COMMAND] \ n ";
  
  
Exit-1;
  
  
}
  
  
 
  
  
# Fork and exec
  
  
My $ status = 0;
  
  
$ SIG {CHLD} = sub {while (waitpid (-1, WNOHANG)> 0) {$ status =-1 unless $? = 0; exit $ status ;}};
  
  
$0 = 'timeout hacked'. $ ARGV [0];
  
  
Defined (my $ child = fork );
  
  
If ($ child = 0)
  
  
{
  
  
My $ cmd = join '', @ ARGV;
  
  
Exec ($ cmd );
  
  
}
  
  
$ SIG {TERM} = sub {kill TERM => $ child };
  
  
$ SIG {INT} = sub {kill INT => $ child };
  
  
 
  
  
 
  
  
# Kill when timeout
  
  
Sleep $ secs;
  
  
$ Status =-1;
  
  
Kill TERM => $ child;
  
  
Sleep 1 and kill INT => $ child if kill 0 => $ child;
  
  
Sleep 1 and kill KILL => $ child if kill 0 => $ child;
  
  
Exit $ status;
  
  
# Usage./t -- timeout = 3 curl http://www.facebook.com
 
 

The above shows that perl actually uses the same method ~

 

This article is from "Fengyun, it's her ." Blog, please be sure to keep this source http://rfyiamcool.blog.51cto.com/1030776/1189520