char * test; // it is null test = malloc(255); // no longer null strcpy(test, "text to go into the string here");
You can also use sprintf or any other str function. If it is a char[] then it should work without the malloc. But do make sure to free the char* after you don't need it anymore.
Oh, that's simple. All you would just use strcpy, or sprintf, and the "text to go into the string here" is replaced with the string (they are both strings).