Date: Sun, 06 Feb 2005 12:15:59 -1000 From: Julian Cowley <julian@lava.net> To: "M. Warner Losh" <imp@bsdimp.com> Cc: dmw@unete.cl Subject: Re: [Hackers] Re: any way to reset errno? Message-ID: <4206971F.1020005@lava.net> In-Reply-To: <20050206.142319.22504831.imp@bsdimp.com> References: <20050206132124.GA746@daemon.unete.cl> <20050206.142319.22504831.imp@bsdimp.com>
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M. Warner Losh wrote:
> In message: <20050206132124.GA746@daemon.unete.cl>
> Daniel Molina Wegener <dmw@unete.cl> writes:
> : Any way to reset errno?
>
> errno = 0;
>
> Routines that return an error status in errno generally don't set it
> to 0 to mean no error.
Which implies errno should never need to be set to zero since the
convention is to only look at errno if a system call fails. The only
time errno needs to be explicitly set (to any value) is when preserving
the error value between system calls. Such as:
if (write(fd, buf, len) < 0) {
int saved_errno;
saved_errno = errno;
close(fd); /* ignore any error */
errno = saved_errno;
return -1;
}
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