Handle IP address convert to int or char(dot IP)

This code will do
1. convert char IP address to four int
2. convert four int var to one int
3. convert four int var to one char

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#include int main() { char arr[] = "192.168.1.102\0 "; //extended to be able to fit up to maximum length unsigned short a, b, c, d; sscanf(arr, "%hu.%hu.%hu.%hu", &a, &b, &c, &d ); arr[0] = '\0'; // cleared to make sure it's not just the same string coming back unsigned long ipAddr = ( a << 24 ) | ( b << 16 ) | ( c << 8 ) | d; a = (ipAddr & (0xff << 24)) >> 24; b = (ipAddr & (0xff << 16)) >> 16; c = (ipAddr & (0xff << 8)) >> 8; d = ipAddr & 0xff; sprintf(arr, "%hu.%hu.%hu.%hu", a, b, c, d); puts(arr); }

Or, these is a api to do it

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int main(){ char ip[] = "192.168.1.102"; long long_address = inet_addr (ip) ; struct in_addr addr; addr.s_addr = long_address; char *dot_ip = inet_ntoa(addr); printf("%s",dot_ip); }

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reference from:
http://www.cplusplus.com/forum/general/9403/
http://stackoverflow.com/questions/1505676/how-to-convert-ip-address-from-char-to-int
http://beej.us/guide/bgnet/output/html/multipage/inet_ntopman.html  (good)
http://beej.us/guide/bgnet/output/html/multipage/inet_ntoaman.html
http://www.aboutmyip.com/AboutMyXApp/IP2Integer.jsp
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後記：
後來發現一篇文章最有用

從 inet_ntoa 看 thread safe 的 API

inet_ntoa會有thread safe的問題，最好直接改用inet_ntop

在WORD中Backspace鍵失效

微軟常常會讓人有無限的驚喜...
前幾天忽然發現，在word和outlook中。反白一段文字，卻無法用backspace(←)刪除。
然而在其他的軟體，甚至是其他的office軟體裡，卻都沒有這個問題。
這困擾了我幾天...
還一度懷疑，是不是本來就沒有這個功能，是我自己憑空想出來的 Orz