Process execution & kill

[Damora]

Hello everybody!
My problem is that I must execute an executable file. This one may hang - as it is a compiled Pascal program that might contain an infinite loop - , so I must limit its execution time to , let us say, 10 seconds. After that time, the process must be killed.
I am almost sure that "alarm(10)" allows me to count 10 seconds, and using "signal(...)" I can receive a signal when the time limit is exceeded. But I do not really know how to execute the file (I have tried with "system(./name_of_the_file)" and the exec family of functions, but I cannot stop execution) and I do not know how to handle the signal. The process goes on and does not stop.
Thanks.

 

[Kenrae]

You should use exec family, and get its pid.
You'll need to use a fork before that. Here's an example:

void main(){
int pid;,dummy

pid=fork();
switch(pid){
  case -1: //Error on fork call
    break;
  case 0: //Child
    //execute your program using exec call
    break;
  default: //Father
    sleep(10);
    kill(pid, SIGKILL);
    wait(&dummy);
    break;
  }
}

 

[Damora]

Thank you very much, it works!!!
I am afraid my search into de Unix C manual has been unuseful, and I would have been lost for years. Had it not been for you...
Thanks again!!!

 

[Damora]

Sorry, I thought it worked but I have realized that it dose not. Your solution only sleeps the process (stops it for 10 seconds), but what I really want is the process to be executed "in the background" and kill it after the mentioned 10 seconds. That is why I told that alarm() might be the solution, but I cannot find any example that works like I want.

 

[Kenrae]

Uh? Father process is the one stopped, not the executed one. So, father process must do another work separately, is that what you mean?
The executed process (Pascal executable) isn't stopped.