commands/gcore/gcore.c

   1 /* gcore - create core file of running process */
   2
   3 #include <sys/types.h>
   4 #include <sys/ptrace.h>
   5 #include <sys/wait.h>
   6 #include <signal.h>
   7 #include <errno.h>
   8 #include <stdio.h>
   9 #include <string.h>
  10 #include <stdlib.h>
  11
  12 int main(int argc, char *argv[])
  13 {
  14   pid_t pid;
  15   int status;
  16
  17   if(argc != 2) {
  18         printf("usage: %s <pid>\n", argv[0]);
  19         return 1;
  20   }
  21
  22   pid = atoi(argv[1]);
  23
  24   if (ptrace(T_ATTACH, pid, 0, 0) != 0) {
  25         perror("ptrace(T_ATTACH)");
  26         return 1;
  27   }
  28
  29   if (waitpid(pid, &status, 0) != pid) {
  30         perror("waitpid");
  31         return 1;
  32   }
  33
  34   while (WIFSTOPPED(status) && WSTOPSIG(status) != SIGSTOP) {
  35         /* whatever happens here is fine */
  36         ptrace(T_RESUME, pid, 0, WSTOPSIG(status));
  37
  38         if (waitpid(pid, &status, 0) != pid) {
  39                 perror("waitpid");
  40                 return 1;
  41         }
  42   }
  43
  44   if (!WIFSTOPPED(status)) {
  45         fprintf(stderr, "process died while attaching\n");
  46         return 1;
  47   }
  48
  49   if (ptrace(T_DUMPCORE, pid, 0, 0)) {
  50         fprintf(stderr, "warning, dumpcore failed (%s)\n", strerror(errno));
  51   }
  52
  53   if (ptrace(T_DETACH, pid, 0, 0)) {
  54         fprintf(stderr, "warning, detaching failed (%s)\n", strerror(errno));
  55   }
  56
  57   return 0;
  58 }