#! problem

#! problem

[Peter Stephenson]

Somebody here tried something like:

#!/bin/zsh -f    
#            ^^^^empty spaces added here
echo your code here

and got back:

/bin/zsh: bad option: -

This is a problem because, once again, previous versions of zsh
weren't so fussy.  (For comparison, ksh reacts similarly but you get
`-f     : bad option(s)' which is at least a little clearer.)  This
happens on IRIX, SunOS 4, AIX and Digital Unix 4.0, though apparently
not on Solaris.

I would think dropping meaningless spaces in an option string
(i.e. when an option letter is expected) again would be harmless.  I
just want to wait for the waves of protest before trying anything.

-- 
Peter Stephenson <pws@ifh.de>       Tel: +49 33762 77366
WWW:  http://www.ifh.de/~pws/       Fax: +49 33762 77413
Deutsches Elektronen-Synchrotron --- Institut fuer Hochenergiephysik Zeuthen
DESY-IfH, 15735 Zeuthen, Germany.

Re: #! problem

[Bart Schaefer]

On Jan 15, 10:37am, Peter Stephenson wrote:
} Subject: #! problem
}
} Somebody here tried something like:
} 
} #!/bin/zsh -f    
} #            ^^^^empty spaces added here

As opposed to ... full spaces?

} I would think dropping meaningless spaces in an option string
} (i.e. when an option letter is expected) again would be harmless.
} I just want to wait for the waves of protest before trying anything.

I don't think *dropping* them is the right idea; that could be pretty
confusing, couldn't it?  I'd say that a space where an option letter
was expected was actually pretty meaning*ful* -- it probably means
that somebody meant to pass two words to the shell, but mistakenly
passed only one.

Possible solutions:

1.  Improve the error message.

	/bin/zsh: bad option character " " in: -

    (There's probably a better improvement.)

2.  Stop parsing options at whitespace, and completely ignore it and
    all the characters that come after it.  I believe BSD 4.2 csh did
    this, if I'm remembering correctly my early days of feeling my way
    through scripting.

3.  As (2), but issue an error if there's anything other than whitespace
    in the trailing part.  I think this is the most reasonable choice, as
    it doesn't silently drop stuff from the #! line (which was mystifying
    when it happened in csh, which is why I'm pretty sure I remember it).

4.  Assume that if whitespace makes it to the option parser, there were
    really supposed to be two arguments, and actually arrange to parse
    it that way, i.e. split the word into two at the whitespace.  I don't
    really think this is a viable solution, not only because it violates
    the whole principle of #! lines (one path plus one argument), but
    because it also could mean arbitrarily increasing the number of words
    in argv.  On the other hand, it makes this work as it appears that it
    should:

	#! /bin/zsh -f -v -x

5.  Ignore whitespace only if it's followed by a `-' and ignore that `-'
    as well; otherwise act like (2).  This also makes "-f -v -x" and the
    like work, but doesn't have the other disadvantages of (4).  It still
    makes zsh a bit mysterious with respect to other programs named on #!
    lines, though, so it's probably not something we should do.

-- 
Bart Schaefer                             Brass Lantern Enterprises
http://www.well.com/user/barts            http://www.nbn.com/people/lantern

Re: #! problem

[Peter Stephenson]

"Bart Schaefer" wrote:
> On Jan 15, 10:37am, Peter Stephenson wrote:
> } Subject: #! problem
> }
> } Somebody here tried something like:
> } 
> } #!/bin/zsh -f    
> } #            ^^^^empty spaces added here
> 
> As opposed to ... full spaces?

mmph.

> 2.  Stop parsing options at whitespace, and completely ignore it and
>     all the characters that come after it.  I believe BSD 4.2 csh did
>     this, if I'm remembering correctly my early days of feeling my way
>     through scripting.
> 
> 3.  As (2), but issue an error if there's anything other than whitespace
>     in the trailing part.  I think this is the most reasonable choice, as
>     it doesn't silently drop stuff from the #! line (which was mystifying
>     when it happened in csh, which is why I'm pretty sure I remember it).

This sounds OK to me, and that's what I've written.

There's one common case (common to me, anyway, I never realised it
wasn't going to work) which isn't handled:

#!/bin/zsh -f -*-ksh-*-

(important if you don't like the new shell-mode in Emacs.)  Looks like
I'll have to get used to writing

#!/bin/zsh -f-*-ksh-*-

which also works as the second - terminates processing.  I suppose
everybody else knew that already.

*** Doc/zsh.texi.opt	Thu Jan 16 09:51:24 1997
--- Doc/zsh.texi	Thu Jan 16 10:33:55 1997
***************
*** 5483,5488 ****
--- 5483,5499 ----
  the specification of option names by glob patterns, clashes with the use of 
  @samp{-m} for setting the @code{MONITOR} option.
  
+ @noindent
+ Note also that whitespace at the end of an otherwise valid option
+ string is ignored.  This is provided for the case when a zsh script is
+ invoked via a line of the form
+ 
+ @code{#!/bin/zsh -@var{option-string}}
+ 
+ @noindent
+ as many systems pass the text following the interpreter name with no
+ further processing.  If any other text follows the whitespace an error
+ is signalled.
  
  @node Shell Builtin Commands, Programmable Completion, Options, Top
  @chapter Shell Builtin Commands
*** Doc/zshoptions.man.opt	Thu Jan 16 09:51:19 1997
--- Doc/zshoptions.man	Thu Jan 16 10:33:01 1997
***************
*** 649,651 ****
--- 649,663 ----
  .BR unsetopt ,
  allowing the specification of option names by glob patterns,
  clashes with the use of \-\fBm\fP for setting the MONITOR option.
+ .PP
+ Note also that whitespace at the end of an otherwise valid option
+ string is ignored.  This is provided for the case when a zsh script is
+ invoked via a line of the form
+ .PP
+ .nf
+ #!/bin/zsh \-\fIoption_string\fP
+ .fi
+ .PP
+ as many systems pass the text following the interpreter name with no
+ further processing.  If any other text follows the whitespace an error
+ is signalled.
*** Src/init.c.opt	Wed Jan  8 11:13:10 1997
--- Src/init.c	Thu Jan 16 10:31:15 1997
***************
*** 205,210 ****
--- 205,211 ----
  
      /* loop through command line options (begins with "-" or "+") */
      while (*argv && (**argv == '-' || **argv == '+')) {
+ 	char *args = *argv;
  	action = (**argv == '-');
  	if(!argv[0][1])
  	    *argv = "--";
***************
*** 237,242 ****
--- 238,251 ----
  		    zerr("no such option: %s", *argv, 0);
  		else
  		    dosetopt(optno, action, 1);
+ 		break;
+ 	    } else if (isspace(**argv)) {
+ 		/* zsh's typtab not yet set, have to use ctype */
+ 		while (*++*argv)
+ 		    if (!isspace(**argv)) {
+ 			zerr("bad option string: `%s'", args, 0);
+ 			exit(1);
+ 		    }
  		break;
  	    } else {
  	    	if (!(optno = optlookupc(**argv))) {

-- 
Peter Stephenson <pws@ifh.de>       Tel: +49 33762 77366
WWW:  http://www.ifh.de/~pws/       Fax: +49 33762 77413
Deutsches Elektronen-Synchrotron --- Institut fuer Hochenergiephysik Zeuthen
DESY-IfH, 15735 Zeuthen, Germany.