everest% cc -g malloc1.c
"malloc1.c", line 17: warning(1551): variable "ptr" is used before its value
          is set
     ptr[16] = 254 ;
     ^

everest% 

everest% a.out
sizeof(A) = 68
sizeof(ptr) = 8
Bus error (core dumped)
everest% 

everest% dbx a.out
dbx version 6.2 Mar  9 1996 15:23:28
Core from signal SIGBUS: Bus error
(dbx) where
>  0 main() ["/home/faculty6/chang/course/cs202/ptr1/malloc1.c":17, 0x10000da0]
   1 __start() ["/vince/6.2-mar09/work/irix/lib/libc/libc_64_M4/csu/crt1text.s":166, 0x10000d18]
(dbx) list
>*  17     ptr[16] = 254 ;
    18  }
(dbx) quit
everest%