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From: woods@gpu.utcs.toronto.edu (Greg Woods)
Date: Sun, 18-Sep-88 23:57:25 EDT
Message-ID: <1988Sep18.235725.15653@gpu.utcs.toronto.edu>
Organization: G. A. W. Consulting
Newsgroups: comp.unix.xenix
Subject: Re: "#!" scripts, kernel patches, and Xenix
Summary: ISC's csh for 386/ix does it "right"
References: <161@tessera.UUCP> <858@viscous> <1458@ssc.UUCP>
Reply-To: woods@gpu.utcs.Toronto.EDU (Greg Woods)

In article <1458@ssc.UUCP> fyl@ssc.UUCP (Phil Hughes) writes:
>In article <858@viscous>, rosso@sco.COM (Ross Oliver) writes:
>| In article <161@tessera.UUCP> jtc@tessera.UUCP (J.T. Conklin) writes:
>| >Has anyone patched the kernel exec routine to execute interpreter
>| >files ("#!" scripts)?
>
>I take it to mean that, at least, SCO hasn't.
>Also, csh only looks for the #, not #! on SCO XENIX (or any other
>system for that matter).

Alas, they certainly hadn't fixed either csh, or exec(), last time I
used Xenix.

The csh port done by ISC for 386/ix is a little more mature.  It does
invoke the correct command interpreter if necessary.

This is all fine and dandy if _everyone_ on your system uses csh.
However, I find it simply ludicrous that the "#!" fix hasn't been done
to any recent, common, implementations of Unix, other than BSD.

Though I don't have the most recent POSIX draft (only Draft 10), it
seems that POSIX won't make this fix mandatory either.

Anyone have any remarks on what might be, or is being, done about this
feature in the so called SysV-BSD merger?  Will this affect POSIX?

On another note, ISC also did a fairly reasonable simulation of job
control too.  They didn't use SXT's, so ^Z doesn't work, and fg doesn't
either.  SysV's lack of proper process group semantics is also a pain.
However, 'jobs' does show background tasks, 'kill %n' works, and 'set
notify' even works.

To continue my questions:  Does anyone know what may be done about
proper job control in the merged SysV-BSD stuff?

I see SIGSTOP and friends, as well as better process group semantics as
necessary.  Shl just doesn't cut it (nor does layers, though it is
better).
-- 
						Greg Woods.

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