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Posting-Version: version B 2.10.1 6/24/83; site watmath.UUCP
Path: utzoo!watmath!idallen
From: idallen@watmath.UUCP
Newsgroups: net.bugs
Subject: CSH `...` command substitution brain damage; not really?
Message-ID: <8365@watmath.UUCP>
Date: Wed, 18-Jul-84 11:27:15 EDT
Article-I.D.: watmath.8365
Posted: Wed Jul 18 11:27:15 1984
Date-Received: Thu, 19-Jul-84 02:43:42 EDT
References: <492@masscomp.UUCP>
Organization: U of Waterloo, Ontario
Lines: 32

The first thing on a command line is expected to be a command word to CSH.  
It is the same sort of word as:

      echo hi >`expression`

CSH expects this word not to contain blanks; you can successfully say:

      `echo date`

but not:

      `echo echo hi`

This may be correct, since one wonders what:

      `expression` arg1 arg2 arg3 arg4

should do.  If <expression> expanded to multiple words, the supposed
args would not be the first ones passed to the command, just as:

      echo hi >`expression`

would not do what you expect if <expression> expanded to multiple
words, only the first of which was taken as the file name for redirection.
It's a case of the shell being conservative about peculiar constructions.

If you tell CSH to re-parse the stuff coming in from `...`, imbedded
blanks expand and your example works:

      eval `grep bleen /etc/rc`
-- 
        -IAN!  (Ian! D. Allen)      University of Waterloo