test3.c

这个是学习嵌入式开发的重要例子

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <signal.h>
#include <string.h>
#include <errno.h>

void signal_handler(int s);
void parent_process_main();
void child_process_main();

int main(int argc, char **argv)
{
  signal(SIGINT, signal_handler);

  pid_t pid;

  //pid_t fork(void);
  if ((pid = fork()) < 0)
  {
    fprintf(stderr, "fork() failed: %s\n", strerror(errno));
    exit(1);
  }
  else if (pid == 0)
  {
    fprintf(stdout, "I'm child process, my pid is %d, my parent pid is %d\n", getpid(), getppid());
    child_process_main();
    exit(0);
  }

  fprintf(stdout, "I'm parent process, my pid is %d, new created child pid is %d\n", getpid(), pid);
  parent_process_main();

  return 0;
}

void signal_handler(int s)
{
  fprintf(stdout, "[%d]Catched %d signal.\n", getpid(), s);
}

void parent_process_main()
{
  for (;;)
  {
  }
}

void child_process_main()
{
  // pid_t setsid(void);
  setsid();
  for (;;)
  {
  }
}