Question

Lets say I have
string1 = "DDD DXXXX"
string2 = "DDXXXX"
string3 = "DXXXX"

and if i want to extract XXXX all the time, then what is the best way in c? substr, strncpy, strndup everything needs a starting position.

Is regex the only option?

Answer 1

Use strstr() to locate the "XXXX":

char string1[] = "DDXXXX";
char* xxxx_ptr = strstr(string1, "XXXX");
if (xxxx_ptr)
{
    /* Do something. */
}