Thread: extracting a substring based on position

If you're allowed to smash the original string, then just put a null-terminator at 10 and return from 5.

i.e.,

Code:

char * substr(char * str, size_t from, size_t to)
{
   size_t len = strlen(str);

   if(from > len || to > len)
      return NULL;

   // end the string at to
   str[to] = '\0';

   return &str[from];
}

Of course if you don't want to modify the original string, then just use memcpy() in the same sort of fashion. Allocating memory for the substring before you copy it in, (from - to) characters, starting from &str[from].

You mean like memcpy?

Code:

memcpy( tohere, fromhere, len );
tohere[ len ] = '\0';

You could of course actually TRY.


Quzah.