c setjmp longjmp

http://coolshell.cn/?s=setjmp

http://www.cnblogs.com/hazir/p/c_setjmp_longjmp.html

 1 double divide(double to, double by, jmp_buf env)
 2 {
 3     if(by == 0)
 4         if (env)
 5             longjmp(env, 1);
 6         else
 7             return 0;
 8     else
 9         return to/by;
10 }
11
12 void f()
13 {
14     jmp_buf env;
15     int ret = setjmp(env);
16     printf("jmp: %d\n", ret);
17     if(ret == 0)
18     {
19         printf("result: %lf\n", divide(2.0, 0, env));
20     }
21     else
22     {
23         printf("error: %d\n", ret);
24     }
25 }