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From: brighton@pixar.UUCP (Bill Carson)
Newsgroups: net.unix-wizards
Subject: possible problem in csh if/then/endif
Message-ID: <113@pixar.UUCP>
Date: Fri, 3-Oct-86 05:10:58 EDT
Article-I.D.: pixar.113
Posted: Fri Oct  3 05:10:58 1986
Date-Received: Sat, 4-Oct-86 11:09:37 EDT
Reply-To: brighton@pixar.UUCP (Bill Carson)
Followup-To: net.unix-wizards
Distribution: net
Organization: Pixar -- Marin County, California
Lines: 34
Keywords: csh parser

consider this:  (as run on a virgin 4.3BSD csh (vax))

% cat -n test.sh

     1	#! /bin/csh -fx
     2	
     3	set machine = string
     4	set host    = string
     5	set foo     = bar
     6	
     7	if ( $machine !~ $host ) then
     8		if ( $foo =~ bar ) then
     9			echo dummy if statement
    10		endif
    11		echo this should not happen
    12	else
    13		echo this should happen
    14	endif

running this works as you would expect, it will echo "this should happen"

Ok, on line 8, if you remove the space between the 'if' and the '(' so that
it looks like this:

     8	if( $foo =~ bar ) then

then it will echo "this should not happen".   I know this sounds confusing,
but extract the shell script, play with it, and you'll see what I mean.
This is most annoying, because I've just been bitten by this bug in our 
backup scripts.  Joe Bob says "pull your hair out"

Can anyone provide an explanation?

			-Bill      ...!{ucbvax,sun}!pixar!brighton