/* xsh_kill.c - xsh_kill */

#include 
#include 
#include 

/*------------------------------------------------------------------------
 * xsh_kill - obtain and print the current month, day, year, and time
 *------------------------------------------------------------------------
 */
shellcmd xsh_kill(int nargs, char *args[]) {

        int32   retval;                 /* Return value                 */
        pid32   pid;                    /* ID of process to kill        */
        char    ch;                     /* Next character of argument   */
        char    *chptr;                 /* Walks along argument string  */

        /* Output info for '--help' argument */

        if (nargs == 2 && strncmp(args[1], "--help", 7) == 0) {
                printf("Usage: %s PID\n\n", args[0]);
                printf("Description:\n");
                printf("\tterminates a process\n");
                printf("Options:\n");
                printf("\tPID \tthe ID of a process to terminate\n");
                printf("\t--help\tdisplay this help and exit\n");
                return OK;
        }

        /* Check argument count */

        if (nargs != 2) {
                fprintf(stderr, "%s: incorrect argument\n", args[0]);
                fprintf(stderr, "Try '%s --help' for more information\n",
                        args[0]);
                return SYSERR;
        }

        /* Compute process ID from argument string */

        chptr = args[1];
        ch = *chptr++;
        pid = 0;
        while(ch != NULLCH) {
                if ( (ch < '0') || (ch > '9') ) {
                        fprintf(stderr, "%s: non-digit in process ID\n",
                                args[0]);
                        return 1;
                }
                pid = 10*pid + (ch - '0');
                ch = *chptr++;
        }
        if (pid == 0) {
                fprintf(stderr, "%s: cannot kill the null process\n",
                        args[0]);
                return 1;
        }

        retval = kill(pid);
        if (retval == SYSERR) {
                fprintf(stderr, "%s: cannot kill process %d\n",
                        args[0], pid);
                return 1;
        }
        return 0;
}