bug#3608: BG processes killed by start-process

bug#3608: BG processes killed by start-process

[JD Smith]

Start-process seems to kill off child processes of which have been put  
into the background.

Create a small shell script "bgtest":

#!/bin/sh
sleep 121 &
exit 0

and now

(start-process "BGTEST" nil "bgtest")

Notice that the sleep process has been killed, rather than waited on.

Is this the intended behavior?  Any thoughts for preventing it (other  
than modifying the script, which I don't control)?

Thanks.



----------------


In GNU Emacs 22.3.1 (i386-apple-darwin9.6.0, Motif Version 2.3.1)
  of 2009-04-29 on terrapin
Windowing system distributor `The X.Org Foundation', version  
11.0.10402000
configured using `configure  '--prefix=/opt/local' '--without-carbon'  
'--with-xpm' '--with-jpeg' '--with-tiff' '--with-gif' '--with-png' '-- 
with-x-toolkit=motif' 'CC=/usr/bin/gcc-4.0' 'CFLAGS=-O2' 'LDFLAGS=-L/ 
opt/local/lib' 'CPPFLAGS=-I/opt/local/include' 'CPP=/usr/bin/cpp-4.0''

Important settings:
   value of $LC_ALL: nil
   value of $LC_COLLATE: nil
   value of $LC_CTYPE: nil
   value of $LC_MESSAGES: nil
   value of $LC_MONETARY: nil
   value of $LC_NUMERIC: nil
   value of $LC_TIME: nil
   value of $LANG: en_US.UTF-8
   locale-coding-system: utf-8
   default-enable-multibyte-characters: t

Major mode: Shell-script

Minor modes in effect:
   TeX-source-specials-mode: t
   which-function-mode: t
   show-paren-mode: t
   tooltip-mode: t
   mouse-wheel-mode: t
   menu-bar-mode: t
   file-name-shadow-mode: t
   global-font-lock-mode: t
   font-lock-mode: t
   blink-cursor-mode: t
   unify-8859-on-encoding-mode: t
   utf-translate-cjk-mode: t
   auto-compression-mode: t
   line-number-mode: t
   transient-mark-mode: identity

Recent input:
<backspace> <backspace> <backspace> <backspace> <backspace>
/ h o m e / j d s m i t h / b i n / b g t e s t " )
<return> <down-mouse-1> <mouse-1> M-: <up> <help-echo>
<down-mouse-3> <mouse-3> <down-mouse-1> <mouse-movement>
<mouse-movement> <drag-mouse-1> <switch-frame> <down-mouse-1>
<mouse-movement> <mouse-1> C-x C-f C-g C-x C-f <M-backspace>
<M-backspace> b i n / b g <tab> t <tab> e <tab> C-x
C-f C-a <right> <right> C-k b i n / t e <tab> <return>
<down> <down> <down> <down> <up> <down> <return> <up>
d i s o w n SPC $ $ C-x C-s M-: <up> <return> <down-mouse-1>
<mouse-1> <backspace> <backspace> % % C-x C-s <down-mouse-1>
<mouse-1> M-: <up> <return> <down-mouse-1> <mouse-1>
<up> C-a C-k C-k C-x C-s <down-mouse-1> <mouse-1> <backspace>
C-x C-s M-: <up> <return> <down-mouse-1> <mouse-1>
M-: <up> C-e <left> <left> <left> <left> <left> <left>
<left> <left> <left> <right> <right> <right> <backspace>
<backspace> <right> <right> <right> <right> b g <return>
<down-mouse-1> <mouse-movement> <mouse-1> M-: <up>
<right> <right> <right> <right> <right> <right> <right>
<right> <right> <right> <right> <right> <right> <right>
<right> <right> <right> <right> <right> <right> <right>
<right> <right> <right> <right> <right> <right> <right>
<right> <right> <right> <right> <right> <right> <right>
<right> <return> <down-mouse-1> <mouse-1> M-: <up>
<right> <right> <right> C-h f d <return> C-g C-h f
<return> <right> <down> <up> <right> <right> <right>
<right> <right> <right> <right> <right> <right> <right>
<right> <right> <right> <right> <right> <right> <right>
<right> <right> <right> <right> <right> <right> <right>
<right> M-d M-d M-d C-d C-e <return> <switch-frame>
<switch-frame> <down-mouse-1> <mouse-movement> <mouse-1>
M-x p r o c <tab> C-h a p r o c e s s <return> M-x
l i s t - p r <tab> <return> <help-echo> <help-echo>
<down-mouse-1> <mouse-1> M-x e m a c s - C-a C-k r
e p <tab> o <tab> r <tab> <return>

Recent messages:
#<process BGTEST> [3 times]
Making completion list...
Quit
Type C-x 1 to remove help window.
#<process BGTEST>
Quit
Loading apropos...done
Type C-x 1 to remove help window.
Making completion list... [2 times]
Loading emacsbug...done


--
  J.D. Smith                  <==> http://tir.astro.utoledo.edu/jdsmith
  Ritter Observatory, MS 113  <==> 419-530-8528 <W>
  University of Toledo        <==> 419-530-5167 <F>
  Toledo, OH 43606            <==>

bug#3608: BG processes killed by start-process

[Lars Magne Ingebrigtsen]

JD Smith <jdtsmith@gmail.com> writes:

> Start-process seems to kill off child processes of which have been put
> into the background.
>
> Create a small shell script "bgtest":
>
> #!/bin/sh
> sleep 121 &
> exit 0
>
> and now
>
> (start-process "BGTEST" nil "bgtest")
>
> Notice that the sleep process has been killed, rather than waited on.
>
> Is this the intended behavior?  Any thoughts for preventing it (other
> than modifying the script, which I don't control)?

I'm unable to reproduce this bug in Emacs 24:

(setq a (start-process "BGTEST" nil "/tmp/bgtest"))
=> #<process BGTEST>
(process-status a)
=> exit

Do you still see this bug in a current Emacs?

-- 
(domestic pets only, the antidote for overdose, milk.)
  bloggy blog http://lars.ingebrigtsen.no/

bug#3608: BG processes killed by start-process

[Andreas Schwab]

JD Smith <jdtsmith@gmail.com> writes:

> Start-process seems to kill off child processes of which have been put
> into the background.
>
> Create a small shell script "bgtest":
>
> #!/bin/sh
> sleep 121 &
> exit 0
>
> and now
>
> (start-process "BGTEST" nil "bgtest")
>
> Notice that the sleep process has been killed, rather than waited on.

That's not a bug.  The session created for the process is closed when
the process exits, which causes the kernel to send SIGHUP to all
remaining processes in the session.

Andreas.

-- 
Andreas Schwab, schwab@linux-m68k.org
GPG Key fingerprint = 58CA 54C7 6D53 942B 1756  01D3 44D5 214B 8276 4ED5
"And now for something completely different."