Hi
On Sat, Oct 28, 2023 at 07:57:54PM +1300, rhys wrote:
> char myBuf[] = { '\x01', '\x04', '\x31', '\x00', '\x00', '\x1D', '\x7E',
> '\xF7' };
> printf ("sizeof (myBuf) = %d\n", sizeof (myBuf));
This is an array, so sizeof() shows the length of that array. Making it
longer would have showed you your mistake directly.
> void process_buffer (char *bufPtr) {
> printf ("sizeof (bufPtr) = %d\n", sizeof (bufPtr));
This is a pointer. A pointer points to somethine else. The size of a
pointer is unrelated to your array.
> produces following output:
> sizeof (myBuf) = 8
> sizeof (bufPtr) = 4
You run on a 32 bit system, so pointers are 4*sizeof(char), aka 4 byte.
> expected output (confirmed on Oracle Linux 8.4):
> sizeof (myBuf) = 8
> sizeof (bufPtr) = 8
Oracle Linux 8 does not support 32 bit systems, so you run on a 64 bit
system. Pointers are 8*sizeof(char), aka 8 bytes.
Arrays and pointers in C are sometimes interchangeable, but with great
precision you found one of the exceptions.
Bastian
--
You! What PLANET is this!
-- McCoy, "The City on the Edge of Forever", stardate 3134.0
