For your first question... this is kinda a tricky question, you'll have to elaborate a bit more on what you want to do.

Well, for your second question, I'd probably get aorund it by just scanning straignt into the string array...
Code:
for (count=0; count!=16; count++) 
{ 
 printf("\nPlease enter the %d interface name >",count); 
 scanf("%s", interface_array[count]); 
}
And for your code, please use code tags, instead of quote tags. Code preserves spacing, and uses standard-width font, which makes code much easier to read in it.