🚀 go-pugleaf

   Date: 9 Feb 90 23:53:27 GMT
   From: milano!peyote!galew_a@cs.utexas.edu  (Andy Galewsky)
   Organization: Capital Area Central Texas Unix Society, Austin, TX
   Sender: bug-bash-request@prep.ai.mit.edu

   I hope I'm not just being stupid (it has happened before) but - when I am
   running BASH-1.04 and I try to execute a Bourne shell script - I can't get 
   /bin/sh to execute it -- BASH tries to do it. I have tried putting #!/bin/sh
   as the first line of the shell script - but BASH continues to try to execute
   it - itself. It doesn't seem right that I have to throw away all of my old
   shell scripts in order to run BASH. This is probably not a BASH bug - but just
   a problem with my understanding of how this works.

			   Thanks 
			    Andy Galewsky
			   Clinical Resource Systems
			   peyote!sneffels!andy
			   galew_a@peyote.cactus.org


System V machines don't pay attention to #! in the first line.  Their
fault, not yours.  If the system call exec () didn't exec the file, then
bash assumes that the file is a bash script.  Not a bad assumption, and
in fact, the same assumption that /bin/sh makes.

Brian

>If the system call exec () didn't exec the file, then
>bash assumes that the file is a bash script.  Not a bad assumption, and
>in fact, the same assumption that /bin/sh makes.

What, the Bourne shell assumes files are bash scripts when exec()
fails?  Nahhhh...

:-) :-) :-) :-) :-) :-) :-) :-) 

Just filling up the net....

In article <9002210515.AA12755@sbphy.Ucsb.EDU>, bfox@sbphy.mit.edu
(Brian Fox) writes:
> 
>   From: milano!peyote!galew_a@cs.utexas.edu  (Andy Galewsky)
> 
>   I hope I'm not just being stupid (it has happened before) but - when I am
>   running BASH-1.04 and I try to execute a Bourne shell script - I can't get 
>   /bin/sh to execute it -- BASH tries to do it.
>   [...]
>
> System V machines don't pay attention to #! in the first line.  Their
> fault, not yours.

I hope I wont be classed as a heritic, but after half an hour of
	a)	loving bash 1.04, but
	b)	working on a system which doesn't accept #!, and
	c)	having bash run scripts itself, but
	d)	the bash echo and the system's echo having different sematics

I added the following patch.  Not very nice, or pretty and certainly
NOT OFFICIAL!!

I define XSHELL=/bin/sh in my .bashrc and all the system scripts work
like they used to :-)

A slightly more substantial patch would probably try to do the #!
stuff itself if XSHELL was defined.

*** execute_cmd.c.orig	Fri Nov  3 21:11:24 1989
--- execute_cmd.c	Tue Feb 20 13:20:19 1990
***************
*** 902,907 ****
--- 902,916 ----
  		      if (args[0][0] == '-')
  			args[0]++;
  
+ 		      {
+ 			char * last_chance_shell = get_string_value ("XSHELL");
+ 			if (last_chance_shell) {
+ 			  execve (last_chance_shell, args, export_env);
+ 			  report_error ("%s: Cannot execute %s", shell_name, last_chance_shell);
+ 			  exit (EXECUTION_FAILURE);
+ 			}
+ 		      }
+ 
  		      exit (main (larry, args, export_env));
  		    }
  		}

Andrew
-- 
Domain address: Andrew.Vignaux@comp.vuw.ac.nz