linux源码之kill.c

#include <stdio.h>#include <stdlib.h>#include <errno.h>#include <sys/types.h>#include <signal.h>int main(int argc, char **argv){    int sig = SIGTERM;    int result = 0;       argc--;    argv++;    if(argc >= 2 && argv[0][0] == '-'){        sig = atoi(argv[0] + 1);        argc--;        argv++;    }    while(argc > 0){        int pid = atoi(argv[0]);        int err = kill(pid, sig);        if (err < 0) {            result = err;            fprintf(stderr, "could not kill pid %d: %s\n", pid, strerror(errno));        }                  argc--;        argv++;    }      return result;}