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Date: Wed, 13 Oct 2021 10:25:12 +0300
From: "Dmitry V. Levin" <ldv@altlinux.org>
To: musl@lists.openwall.com
Message-ID: <20211013072512.GB15338@altlinux.org>
References: <0100017c773d8050-290fe58a-7804-4399-83f8-0ce8d845f7d2-000000@email.amazonses.com>
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In-Reply-To: <0100017c773d8050-290fe58a-7804-4399-83f8-0ce8d845f7d2-000000@email.amazonses.com>
Subject: Re: [musl] errno on writing to read-only files

Hi,

On Wed, Oct 13, 2021 at 01:21:31AM +0000, (GalaxyMaster) wrote:
> Hello,
> 
> I am observing the following on musl and I am not sure that this is the way it
> should be:
> ===
> galaxy@archlinux:~/musl-tests $ cat fput-to-readonly.c 
> #include <stdio.h>
> #include <errno.h>
> 
> int main() {
> 	FILE *f;
> 	int i = 0;
> 	f = fopen("fput-to-readonly.c", "r");
> 	errno = 0;
> 	i = fputs("should not be written", f);
> 	printf("i = %d (should be negative [EOF = %d])\n", i, EOF);
> 	printf("errno = %d\n", errno);

Note that the first "printf" invocation is allowed to clobber errno
and this is not musl-specific.


-- 
ldv