Path: utzoo!utgpu!jarvis.csri.toronto.edu!clyde.concordia.ca!uunet!tut.cis.ohio-state.edu!LINUS.MITRE.ORG!ramsdell
From: ramsdell@LINUS.MITRE.ORG
Newsgroups: gnu.bash.bug
Subject: Re: :${abc?abc} exits
Message-ID: <9001051850.AA13039@huxley.mitre.org>
Date: 5 Jan 90 18:50:31 GMT
References: <9001051836.AA03895@sbphy.Ucsb.EDU>
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Distribution: gnu
Organization: GNUs
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Opps! I forgot to say that I am using bash 1.04 with modifications so
that it runs on a NeXT computer.  By the way, I like the idea of
having an interactive shell that is programmed as one programs the
shell invoked by the library routine named system.

>> Why did you type the ":" in front of everything?  Maybe you meant

The ":" command evaluates its arguments and then ignores the results.
You can use it to make sure that a variable is defined as in:

:${DISPLAY?}	# Exit with error when DISPLAY is not defined.

Cryptic, eh?
John