Re: cast pid_t to int when using *printf

Peter Eisentraut wrote:
> Am Freitag, 24. September 2004 09:34 schrieb Oliver Jowett:
>
>>Neil Conway wrote:
>>
>>>On Fri, 2004-09-24 at 16:51, Oliver Jowett wrote:
>>>
>>>>gcc (3.2.3 on Solaris 9) warns about a couple of places where a pid_t is
>>>>formatted with %d by a printf-family function.
>>>
>>>For curiosity's sake, what formatting escape does gcc prefer?
>>
>>I don't think there is an escape for pid_t, you always have to cast it.
>
>
> I think what he was asking is this: Since pid_t has to be a signed integer
> type, but gcc does not accept %d for it, then it could be that pid_t is wider
> than an int, so casting it to int would potentially lose information.

pid_t on the Solaris/sparc system is a long (but both int and long are
32 bits). Some experimentation shows that gcc is happy with a %ld format
specifier. But compiling the same code on a Linux/x86 system makes gcc
complain when applying %ld to pid_t, so we will need a cast there either
way.

I notice that elog.c casts MyProcPid to long and uses %ld. Amusingly,
MyProcPid is explicitly an int..

-O