Re: [PATCH] http: fix some printf format warnings on 32-bit builds

On 11/11/15 20:31, Eric Sunshine wrote:

On Wed, Nov 11, 2015 at 12:47 PM, Ramsay Jones
[off-list ref] wrote:

quoted

On 11/11/15 01:22, Eric Sunshine wrote:

quoted

On Tue, Nov 10, 2015 at 7:23 PM, Ramsay Jones
[off-list ref] wrote:
My machine is 64-bit, though, so perhaps it's misleading to
characterize this as a fix for 32-bit builds. In particular, off_t is
'long long' on this machine, so it complains about the "long" format
specifier.

... but this seems to imply that sizeof(long) is 4 on your machine, right?
(on x86_64 linux it's 8, which is why I hadn't noticed before).

This code on my Mac:

    printf("sizeof(long)=%zu\n", sizeof(long));
    printf("sizeof(long long)=%zu\n", sizeof(long long));
    printf("sizeof(off_t)=%zu\n", sizeof(off_t));

produces:

    sizeof(long)=8
    sizeof(long long)=8
    sizeof(off_t)=8

The fact that 'long' and 'long long' happen to be the same size (in
this case) is immaterial. What is important is that the code is just
wrong to be using the "%l" specifier for 'long' when the actual
datatype is 'long long' (which is what 'off_t' is under-the-hood in
this case).

Ah. OK, so %ld for long and %lld for long long, I suppose.

Hmm, not that it matters, but I wonder what the PRId64 macro is. ;-)

ATB,
Ramsay Jones