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 == 0)
        if (env)
            longjmp(env, 1);
        else
            return 0;
    else
        return to/by;
}

void f()
{
    jmp_buf env;
    int ret = setjmp(env);
    printf("jmp: %d
", ret);
    if(ret == 0)
    {
        printf("result: %lf
", divide(2.0, 0, env));
    }
    else
    {
        printf("error: %d
", ret);
    }
}