Re: Check if a process exists? (EXTENDING THE QUESTION)

[lucianolnx <lucianolnx@ig.com.br>]

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Today, what are the bests ways to know if a deamon is running without 
knowing its PID ? 

My old technique (used until now), is based on recovering the PID saved by 
the own process in a special and known location (like a file), almost all 
times persisted (PERSISTENCE IS A PROBLEM). 

Luciano 



On Tue, 1 Mar 2005, Hareesh Nagarajan wrote: 

> Hi, 
> 
> Can a process check if a given PID exists or not? In other words can a 
> process check if an unrelated process is alive? Is there any system 
> call that does this? 
> 
Use kill() with a second argument being zero. 

    if (kill(pid, 0) == -1) 
    { 
       /* Process is not there. */ 
    } 
    else 
    { 
       /* Process is alive. */ 
    } 

Holger