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From: dan@haddock.UUCP
Newsgroups: net.unix-wizards
Subject: Re: Why parse lines with colons - (nf)
Message-ID: <216@haddock.UUCP>
Date: Tue, 17-Jul-84 23:45:04 EDT
Article-I.D.: haddock.216
Posted: Tue Jul 17 23:45:04 1984
Date-Received: Sun, 22-Jul-84 03:01:23 EDT
Lines: 25

#R:spuxll:-52600:haddock:16800020:000:593
haddock!dan    Jul 16 13:59:00 1984

> One of the reasons /bin/sh (bsh to those who like csh)
> parses lines with ":" in the beginning is because of
> constructs like the following:
> : ${FOO:-default}

I think you mean
: ${FOO:=default}

> This effectively sets $FOO to a default value if not previously
> set.	The longhand way would be:
> if [ "${FOO}" = "" ]
> then
>	 FOO=default
> fi

No, the "longhand" way would be
    FOO=${FOO:-default}
which isn't very much longer, and has the advantage that it works even if you
set -u (which I usually do).  I don't think this is a good reason to parse
lines with ":".

	Dan Franklin