c setjmp longjmp

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

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

 double divide(double to, double by, jmp_buf env)
 {
     if(by == )
         if (env)
             longjmp(env, );
         else
             return ;
     else
         return to/by;
 }

 void f()
 {
     jmp_buf env;
     int ret = setjmp(env);
     printf("jmp: %d\n", ret);
     if(ret == )
     {
         printf("result: %lf\n", divide(2.0, , env));
     }
     else
     {
         printf("error: %d\n", ret);
     }
 }