$ gdb --args ./a.out big.bad.testfile
[gdb]> run
Starting program: /home/user/a.out big.bad.testfile

Program received signal SIGSEGV, Segmentation fault.
0x08048646 in getinp (filename=0xbf9c75b1 "big.bad.testfile") at fail.c:34
34              arr[pos] = c;
[gdb]> p size
$1 = 65536
[gdb]> p pos
$2 = 33700
[gdb]> p arr[pos-1]
$3 = 9
[gdb]> p arr[pos]
Cannot access memory at address 0x806b000