Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!csd4.milw.wisc.edu!bionet!agate!shelby!rutgers!att!cbnewsh!twb
From: twb@cbnewsh.ATT.COM (thomas.w.beattie)
Newsgroups: comp.sys.att
Subject: Re: $_
Keywords: ksh csh sh $_
Message-ID: <492@cbnewsh.ATT.COM>
Date: 9 May 89 15:03:34 GMT
References: <1083@adds.newyork.NCR.COM>
Reply-To: twb@cbnewsh.ATT.COM (thomas.w.beattie)
Organization: AT&T Bell Laboratories
Lines: 25

In article <1083@adds.newyork.NCR.COM> tanya@adds.newyork.NCR.COM (Tanya Katz) writes:
>In csh, the command & substitution are echoed before being executed, 
>so you can see the horrible things you are doing,  even if you can't
>quite stop them!!  At least if you could see the the argument expanded
>wrong, you can possibly undo the damage.  But, alas there is no
>expansion, and even when you call up a history the $_ appears as $_, and
>you have to trace it back to the offending line.


In ksh you can have filename generation and $-variables expanded.
Since the expansion is done before entering the command you have a chance
to catch a mistake before pressing <RETURN>.

In EMACS mode: <ESC><ESC> expands the current token, as does <ESC>*
	(In versions 11/16/88 and newer <ESC><ESC> only generates unique
	filenames, <ESC>* generates all matching filenames; before 11/16/88
	they were the same.  Treatment of $-variables is the same for both
	in all versions).
	
I routinely use these sequences to avoid typos and other mistakes.
Check out <ESC>= also.
---
Tom Beattie
att!hoqaa!twb
t.w.beattie@att.com