What's a good prototype for write(2)?

[Richard A. O'Keefe]

In article <1988Oct28.170735.23991 at utzoo.uucp> henry at utzoo.uucp (Henry Spencer) writes:
>In article <902 at vsi.COM> friedl at vsi.COM (Stephen J. Friedl) writes:
>>What is a proper prototype for write(2)?
>>	extern int write(int, const void *, unsigned);		or
>>	extern int write(int, const void *, int);
>
>The latter is correct.  See any Unix manual.

Well, if you see the System V Interface Definition, you find in WRITE(BA_OS)
on page 148 of Volume 1
	int write(filedes, buf, nbyte)
	int filedes;
	char *buf;
	unsigned nbyte;
	^^^^^^^^
Hardly surprising, as the argument is often (sizeof something), which is
unsigned.  I read this as meaning that you can write up to USI_MAX-1 bytes
[see p29 to find out what USI_MAX is].  You have to be careful and test
	int n = write(filedes, bug, nbyte);
	unsigned u = n;
	if (n == -1) { there was an error }
	else { u bytes were written }
rather than
	if (n < 0) { there was an error }
*OH* my broken programs...

Oddly enough, in a superb demonstration of consistency at its very best,
the SVID defines fread() and frwrite() in FWRITE(BA_OS) on p87 of the same
volume as taking >>int<< as the type of "size", and you pass in a
(sizeof something) which is in (INT_MAX,USI_MAX) fwrite() will write nothing.