Path: utzoo!utgpu!watmath!clyde!att!pacbell!ames!ncar!gatech!hubcap!ncrcae!ncrlnk!uunet!mcvax!cernvax!ethz!forty2!poole
From: poole@forty2.UUCP (Simon Poole)
Newsgroups: comp.os.minix
Subject: POSIX question (was: Patches for BSD more for ST-Minix 1.1)
Message-ID: <583@forty2.UUCP>
Date: 10 Jan 89 17:07:28 GMT
References: <579@forty2.UUCP>
Reply-To: poole@forty2.UUCP (Simon Poole)
Organization: Exp. Physics University Zuerich
Lines: 41

In article <579@forty2.UUCP> poole@forty2.UUCP (Simon Poole) writes:
>X		- `more' reads from file descriptor 2 (stderr), but
>X		  the standard ST-Minix `init' opens stdout and stdin 
>X                  only for writing:
>X		  Fix: change the modes in the open calls in
>X                       /usr/src/sttools/init.c to 2.
>X		- the `execv' libary call doesn't pass the enviroment
>X                  of the current process to `execve' (this breaks the
>X                  `v' and `!' commands):

Being inquisitive, I consulted IEEE 1003.1 (POSIX, I've only got access
to a 1986 copy of the trial draft standard, is there anything more recent?)
on the above two problems, the second one being easy:

  quoted from section 3.1.2 Execute a File
 
   'For those forms not containing an envp pointer (execl(), execv(),
    execlp(), and execvp()) the enviroment is taken from the external
    variable environ.'

I was however quite suprised to find out that POSIX (well at least the
copy of the standard I've got) does not address the subject of `pre-
opened' files (in Unix normally the files with filehandles 0, 1 and 2)
at all (except that they are inherited over exec's). Now considering
the importance of the `tool' concept in Unix (which depends on some
kind of standard for passing preopened files for input and output to a
program), I'm really amazed that there is no reference at all to this 
subject.

[As far as I can see, the only work around is to use stdio (which
presumely knows what is customary under the hosts operating system)
and get the filehandle for stdout etc. with fileno(3)]

Is this a problem or am I just stupid (more likely)?


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UUCP:   ...mcvax!cernvax!forty2!poole			Simon Poole
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