CVS commit: src/bin/sh

["Robert Elz" <kre%netbsd.org@localhost>]

Module Name:    src
Committed By:   kre
Date:           Fri Mar  1 05:23:35 UTC 2019

Modified Files:
        src/bin/sh: redir.c

Log Message:
Inspired by (really the need for) Maya's patch to pkgsrc/shells/bash
to allow bash to build fdflags on Solaris 10, here are some mods that
fix that, and some other similar issues in the NetBSD version of fdflags.

The bash implementation of fdflags is based upon the one Christos did for
the NetBSD sh, so the issues are similar ... the NetBSD sh cannot yet
(easily anyway) build on anything except NetBSD, so this change makes
no current difference at all (just adds some compile time tests (#ifdef)
which always work out the way things did before, when built on NetBSD).

However, there is no system on which any modern shell can hope to work
which does not support close on exec, or fcntl(F_SETFD,...) to set it.
The O_CLOEXEC and FD_CLOEXEC definitions might not exist, but close on
exec can still be manipulated.   Since the primary rationale for
the fdflags builtin was to be able to manipulate that state bit from
scripts, it would be annoying to lose that one, and keep all the (less
important) others, just because O_CLOEXEC is not defined, so do the
fix (workaround) a different way than was done in the bash patch.

Further, more than fdflags() will fail if O_CLOEXEC is not defined,
so handle that as well.

Also fix another oddity ... (noticed by reading the code) - if
fcntl(F_GETFL,...) returned any bits set that we don't understand,
the code was supposed to simply print their values as a hex constant,
when fdflags is run with -v.    However, the getflags() function was
clearing all bits that the code did not know about ... so there is
no way any unknown bit could ever make it out to be printed.  Handle
that a different way - instead of clearing unknown bits, clear any
bits that get returned which we understand, but do not want to deal
with (stuff like O_WRONLY, which should not be returned from the
fcntl(), but who knows...)   Leave any unknown bits that happen to be
set, set, so that printone() can display them if appropriate.
(This is most likely to happen when running an older shell on a new
kernel where the kernel supports some new flag that the shell has
not been taught to understand).

NFCI that anyone should notice anytime soon.


To generate a diff of this commit:
cvs rdiff -u -r1.64 -r1.65 src/bin/sh/redir.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.