On Mon, 3 Jan 2005 11:40:00 -0800
Chris Pressey <cpressey@catseye.mine.nu> wrote:
> Or to take another example, this one from SUSv3:
>
> "SYNOPSIS
>
> #include <stdio.h>
> ...
> int snprintf(char *restrict s, size_t n,
> const char *restrict format, ...);
> ...
>
> RETURN VALUE
>
> ...
> Upon successful completion, the snprintf() function shall return
> the number of bytes that would be written to s had n been
> sufficiently large excluding the terminating null byte."
My mistake: snprintf can return -1, according to POSIX, but our manual
page is sufficiently confusing about it that I read it as meaning that
it cannot. I'll try to fix our manual page.
> In other words, snprintf can never return a negative number. Yet its
> return value is signed. This means that the fairly common idiom
>
> if (snprintf(buf, sizeof(f), f, ...) > sizeof(f)) { err(); }
This also means this idiom is an incomplete check, and I'll fix them as
I come to them.
-Chris