From: "Alejandro Colomar (man-pages)" <alx.manpages@gmail.com>
To: mtk.manpages@gmail.com
Cc: libc-alpha@sourceware.org, linux-man@vger.kernel.org,
Ciprian Dorin Craciun <ciprian.craciun@gmail.com>,
Florian Weimer <fweimer@redhat.com>
Subject: Ping: [PATCH v4] system.3: Document bug and workaround when the command name starts with a hypen
Date: Mon, 18 Jan 2021 16:28:37 +0100 [thread overview]
Message-ID: <e6ee2473-9096-0d6e-b793-c90e03bc6dfc@gmail.com> (raw)
In-Reply-To: <a89dea2b-5b26-040a-2f12-3e096756f118@gmail.com>
Hi Michael,
Ping!
And now I noticed a typo in the subject:
s/hypen/hyphen/
Thanks,
Alex
On 1/8/21 3:28 PM, Alejandro Colomar (man-pages) wrote:
>
>
> On 1/8/21 3:22 PM, Alejandro Colomar wrote:
>> man-pages bug: 211029
>> https://bugzilla.kernel.org/show_bug.cgi?id=211029
>>
>> Complete workaround
>
> Maybe a bit more readable:
> Complete workaround example
>
>
>> (it was too long for the page, but it may be useful here):
>>
>> ......
>>
>> $ sudo ln -s -T /usr/bin/echo /usr/bin/-echo;
>> $ cc -o system_hyphen -x c - ;
>> #include <stdlib.h>
>>
>> int
>> main(void)
>> {
>> system(" -echo Hello world!");
>> exit(EXIT_SUCCESS);
>> }
>>
>> $ ./system_hyphen;
>> Hello world!
>>
>> Reported-by: Ciprian Dorin Craciun <ciprian.craciun@gmail.com>
>> Cc: Florian Weimer <fweimer@redhat.com>
>> Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
>> ---
>>
>> D'oh!
>>
>> man3/system.3 | 20 ++++++++++++++++++++
>> 1 file changed, 20 insertions(+)
>>
>> diff --git a/man3/system.3 b/man3/system.3
>> index 753d46f7d..ead35ab30 100644
>> --- a/man3/system.3
>> +++ b/man3/system.3
>> @@ -255,6 +255,26 @@ are not executed.
>> Such risks are especially grave when using
>> .BR system ()
>> from a privileged program.
>> +.SH BUGS
>> +.\" [BUG 211029](https://bugzilla.kernel.org/show_bug.cgi?id=211029)
>> +.\" [Glibc bug](https://sourceware.org/bugzilla/show_bug.cgi?id=27143)
>> +.\" [POSIX bug](https://www.austingroupbugs.net/view.php?id=1440)
>> +If the command name starts with a hyphen,
>> +.BR sh (1)
>> +interprets the command name as an option,
>> +and the behavior is undefined.
>> +(See the
>> +.B \-c
>> +option to
>> +.BR sh (1).)
>> +To work around this problem,
>> +prepend the command with a space as in the following call:
>> +.PP
>> +.RS 4
>> +.EX
>> + system(" \-unfortunate\-command\-name");
>> +.EE
>> +.RE
>> .SH SEE ALSO
>> .BR sh (1),
>> .BR execve (2),
>>
>
--
Alejandro Colomar
Linux man-pages comaintainer; https://www.kernel.org/doc/man-pages/
http://www.alejandro-colomar.es/
next prev parent reply other threads:[~2021-01-18 15:30 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-04 15:13 [RFC] system.3: Document bug when the command name starts with a hypen Alejandro Colomar
2021-01-04 15:54 ` Ciprian Dorin Craciun
2021-01-04 18:04 ` [PATCH] system.3: Document bug and workaround " Alejandro Colomar
2021-01-04 18:32 ` Alejandro Colomar (man-pages)
2021-01-04 20:02 ` Alejandro Colomar (man-pages)
2021-01-08 14:15 ` [PATCH v2] " Alejandro Colomar
2021-01-08 14:20 ` [PATCH v3] " Alejandro Colomar
2021-01-08 14:22 ` [PATCH v4] " Alejandro Colomar
2021-01-08 14:28 ` Alejandro Colomar (man-pages)
2021-01-18 15:28 ` Alejandro Colomar (man-pages) [this message]
2021-01-18 15:37 ` Ping: " Michael Kerrisk (man-pages)
2021-01-18 15:45 ` Alejandro Colomar (man-pages)
2021-01-18 15:58 ` Michael Kerrisk (man-pages)
2021-01-18 16:11 ` Alejandro Colomar (man-pages)
2021-01-18 15:36 ` Michael Kerrisk (man-pages)
2021-01-18 15:35 ` Michael Kerrisk (man-pages)
2021-01-05 13:23 ` [RFC] system.3: Document bug " Michael Kerrisk (man-pages)
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