/bin/ksh vs /usr/xpg4/bin/sh

[Rich Teer]

Hi all,

I have a couple of questions regarding /usr/xpg4/bin/sh and
/bin/ksh. On Solaris 8 (and perhaps earlier releases I don't
have to hand here), /usr/xpg4/bin/sh is a symbolic link to
/bin/ksh, but on Solaris 9 it isn't. Is there any reason for
this? Also, in S9 the files have different sizes, suggesting
that they're no longer identical. If that's the case, what,
in a nutshell, are the differences between the two?

A side observation is that standard conforming apps now use
/usr/xpg4/bin/sh instead of /bin/ksh, when using system or
popen, as the man pages for those functions state.

TIA,

--
Rich Teer, SCNA, SCSA

President,
Rite Online Inc.

Voice: +1 (250) 979-1638
URL: [url]http://www.rite-online.net[/url]

[Paul Eggert]

Rich Teer <rich.teer@rite-group.com> writes:

> /usr/xpg4/bin/sh is a symbolic link to /bin/ksh, but on Solaris 9 it
> isn't. Is there any reason for this?

It's the same reason that Bash behaves differently if you invoke it as
/bin/sh on GNU/Linux systems. Namely, in a few cases the POSIX
standard requires behavior that the ksh developer thinks is bogus.
This is briefly discussed in the ksh man page on Solaris 9.
For example, on Solaris 9:

Command Result in /bin/ksh Result in /usr/xpg4/bin/sh
echo $((010+10)) 20 18
[ 10 -le $((011)) ] true false

It's not just Solaris 9, by the way. It also happens on Solaris 8
after you install Sun patch 110662-06 or later. The POSIX-conformance
bug hasn't been fixed on Solaris 7; dunno if it ever will be.

/bin/bash conforms to POSIX here, so it agrees with /usr/xpg4/bin/sh.

[Markus Gyger]

Rich Teer <rich.teer@rite-group.com> writes:

> On Solaris 8 (and perhaps earlier releases I don't
> have to hand here), /usr/xpg4/bin/sh is a symbolic link to
> /bin/ksh, but on Solaris 9 it isn't.

/usr/xpg4/bin/sh evaluates $((010)) to 8, /usr/bin/ksh
to 10. $((8#10)) evaluates to 8 on both. See man ksh(1).
/usr/xpg4/bin/sh is now part of SUNWcsu (core bundle),
before it belonged to SUNWxcu4 (optional).


Markus

[Rich Teer]

On 5 Aug 2003, Markus Gyger wrote:

> /usr/xpg4/bin/sh evaluates $((010)) to 8, /usr/bin/ksh
> to 10. $((8#10)) evaluates to 8 on both. See man ksh(1).
> /usr/xpg4/bin/sh is now part of SUNWcsu (core bundle),
> before it belonged to SUNWxcu4 (optional).

Got it; thanks guys.

--
Rich Teer, SCNA, SCSA

President,
Rite Online Inc.

Voice: +1 (250) 979-1638
URL: [url]http://www.rite-online.net[/url]