Re: Bug in shell.el: explicit-bash-args does not work for bash 1.x

[storm@cua.dk (Kim F. Storm)]

"Stefan Monnier" <monnier+gnu/emacs@rum.cs.yale.edu> writes:

> > (let* ((prog (or (and (boundp 'explicit-shell-file-name) explicit-shell-file-name)
> > 		 (getenv "ESHELL") shell-file-name))
> >        (name (file-name-nondirectory prog)))
> >   (if (and (equal name "bash")
> > 	   (file-executable-p prog)
> > 	   (string-match "bad option"
> > 			 (shell-command-to-string (concat prog " --noediting"))))
> >       '("-i")
> >     '("--noediting" "-i")))
> 
> I must say I don't like the idea of running a program when loadng
> a .el file.  It's already done at various places, tho.
> 
> There is no strong reason, but one of the recent problem I came
> across in this area is that process operations don't work properly during
> dumping (the handling of sigchld is explicitly not turned on because
> it can supposedly prevent unexec from working right).
> 

The following code doesn't execute the program; it does a brute-force
check for the version of the bash program by looking inside the
executeable.  This works for me on GNU/Linux -- again, if it
doesn't work on other platforms, it doesn't do any worse than
the current default...

(let* ((prog (or (and (boundp 'explicit-shell-file-name) explicit-shell-file-name)
		 (getenv "ESHELL") shell-file-name))
       (name (file-name-nondirectory prog)))
  (if (and (equal name "bash")
	   (file-executable-p prog)
           (file-readable-p prog)
	   (with-temp-buffer
	     (insert-file-contents-literally prog)
	     (goto-char (point-min))
	     (search-forward "@(#)Bash version 1" nil t)))
      '("-i")
    '("--noediting" "-i")))

-- 
Kim F. Storm <storm@cua.dk> http://www.cua.dk