fork(1) download
copy 
  1. #include <cstring>
  2. #include <iostream>
  3. #include <cstdlib>
  4. using std::string;
  5. using std::cout;
  6. using std::memcpy;
  7.  
  8. namespace ptt_demo {
  9.  
  10. union IPv4 {
  11.     int _i;
  12.     struct {
  13.         unsigned char b1, b2, b3, b4;
  14.     } _d;
  15. };
  16.  
  17. int inet_pton4 (char const *src, unsigned char *dst);
  18.  
  19. }
  20.  
  21. int main() {
  22.     std::string str_ip("140.127.34.222");
  23.     ptt_demo::IPv4 ip;
  24.  
  25.     ptt_demo::inet_pton4(str_ip.c_str(), (unsigned char*)&(ip._i));
  26.  
  27.     std::cout << str_ip << " in integer form is: " << ip._i
  28.               << "...(why would you want to see the value?)\n"
  29.  
  30.               << "It also equals to "
  31.               << (int)ip._d.b1 << '.'
  32.               << (int)ip._d.b2 << '.'
  33.               << (int)ip._d.b3 << '.'
  34.               << (int)ip._d.b4 << '\n';
  35.  
  36. }
  37.  
  38. #define NS_INADDRSZ 4
  39. int ptt_demo::inet_pton4 (char const *src, unsigned char *dst) {
  40.     int saw_digit, octets, ch;
  41.     unsigned char tmp[NS_INADDRSZ], *tp;
  42.  
  43.     saw_digit = 0;
  44.     octets = 0;
  45.     *(tp = tmp) = 0;
  46.     while ((ch = *src++) != '\0') {
  47.         if (ch >= '0' && ch <= '9') {
  48.             unsigned newv = *tp * 10 + (ch - '0');
  49.  
  50.             if (saw_digit && *tp == 0)
  51.                 return (0);
  52.             if (newv > 255)
  53.                 return (0);
  54.  
  55.             *tp = newv;
  56.  
  57.             if (!saw_digit) {
  58.                 if (++octets > 4)
  59.                     return (0);
  60.                 saw_digit = 1;
  61.             }
  62.         }
  63.         else if (ch == '.' && saw_digit) {
  64.             if (octets == 4)
  65.                 return (0);
  66.             *++tp = 0;
  67.             saw_digit = 0;
  68.         }
  69.         else
  70.             return (0);
  71.     }
  72.     if (octets < 4)
  73.         return (0);
  74.     memcpy (dst, tmp, NS_INADDRSZ);
  75.     return (1);
  76. }
  77.  
Success #stdin #stdout 0.02s 2856KB
comments (?)
stdin
copy 
Standard input is empty
stdout
copy 
140.127.34.222 in integer form is: -568164468...(why would you want to see the value?)
It also equals to 140.127.34.222
https://ideone.com/bdqk1
language:
C++ (gcc 8.3)
created:
13 years ago
visibility:
public

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!