Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!tut.cis.ohio-state.edu!AUREL.CALTECH.EDU!bfox
From: bfox@AUREL.CALTECH.EDU (Brian Fox)
Newsgroups: gnu.bash.bug
Subject: File Name Globbing
Message-ID: <8907170737.AA04585@aurel.caltech.edu>
Date: 17 Jul 89 07:37:29 GMT
References: <8907160207.AA22322@comp.vuw.ac.nz>
Sender: daemon@tut.cis.ohio-state.edu
Reply-To: bfox@aurel.caltech.edu.date.sun,
        16 Jul 89 14:05:56 +1200
   From: Ray Nickson <nickson@comp.vuw.ac.nz>
Distribution: gnu
Organization: GNUs Not Usenet
Lines: 37


   All right, time for me to stick my neck out again.  The patch at the
   end implements behaviour that is almost this; I despise csh's 
   `No Match' whining so much that I refuse to make an empty glob an
   error.  If this causes some scripts to hang reading stdin, then you
   bought it, you pay for it.

   This patch should be considered experimental; I don't intend to put it
   into the installed bash here.  While I like the idea, I'm unhappy that
   I had to change the globbing semantics to such an extent to make this
   work comfortably; in particular, I've hacked gloobing so that the
   first word of a command is _never_ globbed.  I can't think why anyone
   would want the first word globbed, but still...  The reason I did this
   was that `[' is a perfectly valid (and oft-used) command; perhaps the
   best solution is to say that invalid (as opposed to empty) globbing
   characters should be left as is.  Discussion?

1) Your patch closely matches mine, excepting two things.  The first is
   the name of the variable; I used "allow_null_glob_expansion".  The
   second is the excepting the first word of the command.  I didn't do
   this, mostly because it didn't occur to me.  But it brings up an
   interesting point.  You asked when someone would use globbing
   characters in a command.  The answer is: whenever they thought it
   would ease typing, just as in any other situation.  Perhaps the name
   of the command to run in the current directory is
   "please_run_this_command".  In that case, "ple*nd" will run that
   command, and will have saved the user much typing.

2) You say the reason that you didn't expand the first word is because
   you know of a command that contains a globbing character.  Well, this
   is a much better argument for Bourne shell behaviour than any other I
   have thought of, since the first word of a command is not the only
   place you will see a globbing character.  In the "if" command is
   another place.  As the second word in an "eval" command is another
   place.

Brian Fox