I think the solution from JMS is probably the best
Code:
char buff[128];

memset( buff, 'A', sizeof( buff ) -1 );
buff[ sizeof(buff)-1 ] = '\0';
Also, call me crazy, but I recall when initializing arrays, you need to use the initializer list
Code:
char buff[128] = {'\0'};
So I don't think either of these are correct for initializing an array
Code:
char buff[128] = 0;
OR
char buff[128] = '\0'