Question

How to get a portion of a string.

For Example, the string is:

Input String: “53 56 4B 00 00 41 41 2F 41 54 43 43 54 52 31 2E 41 54 31 2E 4E 37 38”

               |                                        |
              ptr1                                     ptr2  

ptr1 It’s always going to be at the 7th position starting from left to right

ptr2 It’s always going to be at the 13th position starting from right to left

Output string:

4B 00 00 41 41 2F 41 54 43 43 54 52 31 2E 41 54 31

Answer 1

In C:

char substr[MAX_LEN + 1];

strncpy(substr, input + 6, MAX_LEN);
substr[strlen(substr) - 12] = '\0';

In C++:

substr = input.substr(6, input.size() - (6 + 12));

This does no error handling on the input string.