#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/user.h>
#include <sys/ptrace.h>
#include <asm/ptrace.h>
#include <sys/signal.h>

#define REGN (FRAME_SIZE+1)

const char *reg_names[REGN] = {
  /*  0 */ "ebx", "ecx", "edx", "esi", "edi", "ebp", "eax", "ds",
  /*  8 */ "es", "fs", "gs", "orig_eax", "eip", "cs", "eflags", "esp",
  /* 16 */ "ss", "xxx"
};

int
main()
{
  pid_t pid = fork();
  if (pid == -1) {
    perror("fork");
    exit(1);
  }
  else if (pid == 0) {
    int r;
    r = ptrace(PTRACE_TRACEME, 0, NULL, NULL);
    if (r == -1) {
      perror("ptrace(PTRACE_TRACEME)");
    }
    kill(getpid(), SIGINT);
    exit(0);
  }
  else {
    int r, i, status;
    unsigned long regs[REGN];
    r = waitpid(pid, &status, 0);
    if (r == -1) {
      perror("waitpid");
    }
    for (i = 0; i < REGN; ++i)
      regs[i] = 0xdeafbeefUL;
    r = ptrace(PTRACE_GETREGS, pid, NULL, (void *) &regs);
    if (r == -1) {
      perror("ptrace");
    }
    for (i = 0; i < REGN; ++i)
      printf("%2d: %-8s 0x%08x\n", i, reg_names[i], regs[i]);
    ptrace(PTRACE_KILL, pid, NULL, NULL);
  }
  return 0;
}