IPv4 Address

Ask about general coding issues or problems here.

Moderators: egami, macek, gesf

Post Reply
php-forum Fan User
php-forum Fan User
Posts: 73
Joined: Wed Jun 12, 2013 9:30 pm

Mon Apr 11, 2016 5:09 am


Following are steps to check whether a given string is valid IPv4 address or not:
step 1) Parse string with “.” as delimiter using “strtok()” function.
e.g. ptr = strtok(str, DELIM);
Run on IDE
step 2)
……..a) If ptr contains any character which is not digit then return 0
……..b) Convert “ptr” to decimal number say ‘NUM’
……..c) If NUM is not in range of 0-255 return 0
……..d) If NUM is in range of 0-255 and ptr is non-NULL increment “dot_counter” by 1
……..e) if ptr is NULL goto step 3 else goto step 1
step 3) if dot_counter != 3 return 0 else return 1.

Post Reply