C program to kill process

kdelover · 01-10-2013, 03:24 AM

Hi folks,

I am trying to write a C program to kill running processing by their process ids.Although,i have been able to get pids,but i cant seem to kill them.Basically,i programmed in perl and python not in C.So,kindly be gentle

Code:

#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <error.h>
#include <signal.h>
#include <unistd.h>
#include <syslog.h>

int main()
{
    FILE *getPIDS;
    char line[130];
    pid_t killpid;
    // setuid to that of root//
    pid_t mypid   = getpid();
    pid_t myppid  = getppid();
    getPIDS = popen("pidof -x yes","r");
    while (fgets(line,sizeof line,getPIDS)) {
            printf("KILL PID: %s",line);
            kill(line,SIGKILL);
    }
}

Output:

Code:

# ./killpids
KILL PID: 11251 11250

414N · 01-10-2013, 03:32 AM

I would suggest you to read first the manual for the kill system call:

Code:

man 2 kill

kdelover · 01-10-2013, 03:56 AM

Code:

int i = atoi(line);
printf("pid: %d",i);
kill(i,SIGKILL);

This works for me.But this will only 1 process and thats the first one.

linosaurusroot · 01-10-2013, 04:37 AM

Quote:

Originally Posted by kdelover

Code:

int i = atoi(line);
printf("pid: %d",i);
kill(i,SIGKILL);

This works for me.But this will only 1 process and thats the first one.

That is correct - the PID is like an integer (pid_t to be exact). You cannot use a string here.

Using a negative number you can signal a whole process group in one call.

SIGTERM is preferable to SIGKILL to start with.