signallinuxexample.c

关于signal信号的例子代码

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

void foo(int s);

int main(int argc, char **argv)
{
  void (*original) (int);

  //void (*signal(int sig, void (*func)(int)))(int);
  //if (signal(SIGKILL, foo) == SIG_ERR)
  //if (signal(65, foo) == SIG_ERR)
  //if ((original = signal(SIGINT, foo)) == SIG_ERR)
  if ((original = signal(SIGQUIT, foo)) == SIG_ERR)
  {
    fprintf(stderr, "signal() failed: %s\n", strerror(errno));
    exit(1);
  }

  fprintf(stdout, "Original signal handler is %p\n", original);

#if 0
  if ((original = signal(SIGINT, foo)) == SIG_ERR)
  {
    fprintf(stderr, "signal() failed: %s\n", strerror(errno));
    exit(1);
  }

  fprintf(stdout, "Original signal handler is %p\n", original);
  fprintf(stdout, "foo: %p\n", foo);
#endif

#if 1
  //int execl(const char *path, const char *arg, ...);
  if (execlp("less", "less", "test1.c") < 0)
  {
    fprintf(stderr, "execl() failed: %s\n", strerror(errno));
    //perror("excel() failed");
  }
#endif

  for (;;)
  {
    sleep(1);
  }

  return 0;
}

void foo(int s)
{
  fprintf(stderr, "Caught signal %d\n", s);
}