Date: Fri, 30 Jul 2004 07:30:25 GMT From: SAKUMA takayuki <takayuki@finet.fujitsu.com> To: freebsd-bugs@FreeBSD.org Subject: Re: misc/69788: The processing result of strtoul() cannot judge whether it is an error. Message-ID: <200407300730.i6U7UP3O069454@freefall.freebsd.org>
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The following reply was made to PR misc/69788; it has been noted by GNATS.
From: SAKUMA takayuki <takayuki@finet.fujitsu.com>
To: sos22@cantab.net
Cc: freebsd-gnats-submit@FreeBSD.org, sos22@srcf.ucam.org
Subject: Re: misc/69788: The processing result of strtoul() cannot judge
whether it is an error.
Date: Fri, 30 Jul 2004 16:24:42 +0900 (JST)
> In my tests, strtoul correctly leaves errno at 0:
> errno=0;
> ul = strtoul("4294967295", &p, 10);
> o_errno = errno;
> printf("ul=%lu,*p=%x,errno=%d(%s)\n", ul, *p, o_errno,strerror(errno));
>
> gives the result ``ul=4294967295,*p=0,errno=0(Unknown error: 0)'', as
> expected. The problem with the original test case is that strerror()
> is setting errno to EINVAL (because 0 isn't a valid error number)
> before errno is pushed on the stack for printf (the order in which
> function arguments are evaluated is undefined in C).
ul = strtoul("4294967296", &p, 10);
ul = strtoul("4294967295", &p, 10);
2nd strtoul() will success, but errno == ERANGE.
Is it necessary to set errno as 0 before calling 2nd strtoul() ?
------
takayuki@finet.fujitsu.com
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