Killing all off-spring processes

pids="$pids $!"
kill $pids

Hi. Thanks for the respond.

But I could not find pids on my system (Vector Linux).
Seeking it on google find a lot of pids but nothing close for this problem.

Let me restate my goal. Here is the situation.

- login-shell.
+---startx
+---X-init
+---WM-menu
    +---my-MAIN-script
         +---my-child-1
         +---my-child-2
               +---my-grand-child-21
               +---my-grand-child-22
               +---my-grand-child-2N
         +---my-child-M

So basically, I want to launch X-GUI with a WM-menu.
The users able to choose a WM (windows manager).
The WM-Menu then will launch the MAIN script, which will launch various programs (child 1...M).
When the user quit, I want that the MAIN script will kill all of the child, grand-child,
grand-grand child etc ... then return back to the WM-Menu.

Here is my not-working-yet MAIN-script (for launching XFCE4)

----------------------
[code]
#!/bin/sh
#Launching XFCE4 with goodies

# this supposed to be set this process as group leader
#but no effect so far
set -m

# launch the goodies
xfce-iconbox
xfdesktop &

# launch the main panel
xfce4-panel

# the panel exit on user command
# during the session the user may launch any application using the xfce4-panel or the xfdesktop.
# oddly enough, XFCE4 don't kill the applications.


# this kills the goodies
skill xfce-iconbox
skill xfce-xfdesktop

# this was only checking what process still running
ps

# the script exit
exit 0


# I expect that the applications would be killed after exiting
# but I found the applications were still hanging around
# messing with the WM-Menu.
[/code]
---------------

Thanks for your help and patience.

$! only returns the pid of the last backgrounded process

Kocil, there is no direct way (that I know of) of doing what you are looking for from the shell

the only way that I can think of is to do a ps, extract all entries with the name of your program and do an explicit kill for all of them... but this raises the issue of running multiple instances of our program

Thanks sunny.
In that situation,
suppose I call ps on the end of the script.
We will gave someting like this, right

PID    TTY    TIME CMD
....
...
9999   ttt    00:00  main-script
....
....

I can parse it to get the PID and kill them.
But the question is,
how we can determines the child processes ?
Is that guaranted that the ROWS after the
main-script are the childs ?
I found that the PIDs do not always not ordered,
it will roll back after 32xyz.

Thanks.

>> We will gave someting like this, right.

Syntax error. Should be
We will get ...

PID    TTY    TIME CMD
....
...
9999   ttt    00:00  main-script
....
....
>Is that guaranted that the ROWS after the
>main-script are the childs ?
No
>>how we can determines the child processes ?
As far as I remember, they have the same CMD field ... pls check

Do you mean CMD the 4th field ?
That field does not say something about parent - child relations.

>That field does not say something about parent - child relations
I agree but children are launched with the same name ... If you are simply creating multiple processes to do a task in parallel, this should suffice

just checked the man page of ps ... there is option of getting ppid using %p specifier ... but it will be good amount of coding using that method

something like

get your process id ... get all processes with ppid as your process id .. continue recursively until a search does not turn up a new process ...

Just thought of another way ... execute a setsid in the topmost process ... it will become session leader
then a kill with -n flag will send a signal to all the processes in this group and it includes all the children, grand children etc (unless you are doing a setsid in one of them and setting a new leader)

Unfortunatelly, I have cecked it again, XFCE launches apps as its own setsid.
The parent is 1 (init). Here is the result from ps -H.
=========
PID TTY          TIME CMD
  697 ?        00:00:00 xfe
  695 ?        00:00:00 nedit
  690 ?        00:00:00 aterm
  693 ttyp0    00:00:00   bash
  683 ?        00:00:00 dfm
  678 ?        00:00:00 xfce-mcs-manage
  652 ?        00:00:00 kapmd
  578 tty6     00:00:00 bash
  637 tty6     00:00:00   startx
  649 tty6     00:00:00     xinit
  650 ?        00:00:02       X
  662 tty6     00:00:00       XwmMenu
  670 ?        00:00:00         xinitrc.xfce4
  679 ?        00:00:00           xfwm4
  680 ?        00:00:00           xfbackdrop
  682 ?        00:00:00           xfce4-panel
======

What a life ...
Fluxbox, WindowsMaker, and XFCE4 have the same problem.
But IceWM and KDE do kill the applications.

I raised the points to 500.
Please help ...

myPID=`awk '/^PPid/{print $2}' /proc/self/status`
kill ps axl|awk '($4 == "'$PiD'"){print $3}'
# to be improved in many way (returns at least 2 pids which are no longer existing)

opps, typo
pleace replace PiD by myPID

On solaris we have option to show pid and ppid inthe same line.
u can capture ppid of the script once the script starts. with invoking
script_ppid= ps -aef | grep script_name and capturing the pid field.  ( this must the first column).

and when u try to kill it , just get the ppid field and try to match with pid of the above and kill them all.

or u can do more thing. all these processes and sub processes might be having the same
tty filed.
so get the first ppid with script_name and kill everything aasociated with this tty except the ppid one.

I login as user vec on the tty2 and tty6. Then startx from tty6.
Here is the more complete ps output.

  PID  PGID   SID TTY          TIME CMD
 2421  2421  2421 ?        00:00:00 nedit
 2381  2381  2381 ?        00:00:00 run-mozilla.sh
 2388  2381  2381 ?        00:00:17   MozillaFirebird
 2390  2381  2381 ?        00:00:00     MozillaFirebird
 2391  2381  2381 ?        00:00:00       MozillaFirebird
 2392  2381  2381 ?        00:00:00       MozillaFirebird
 2393  2381  2381 ?        00:00:00       MozillaFirebird
 2394  2381  2381 ?        00:00:00       MozillaFirebird
 2356  2356  2356 tty2     00:00:00 bash
 2368  2368  2356 tty2     00:00:00   mc
 2371  2371  2371 ttyp0    00:00:00     bash
 2348  2348  2348 ?        00:00:00 xfe
 2324  2321   578 tty6     00:00:00 xterm
 2326  2326  2326 ttyp2    00:00:00   bash
 2322  2320   578 tty6     00:00:00 dfm
 2318  2317   578 tty6     00:00:00 xfwm4
 2316  2316  2316 ?        00:00:00 xfce-mcs-manage
 1841     1     1 ?        00:00:00 kapmd
  578   578   578 tty6     00:00:00 bash
 1827  1827   578 tty6     00:00:00   startx
 1838  1827   578 tty6     00:00:00     xinit
 1839  1839   578 ?        00:00:37       X
 1851  1851   578 tty6     00:00:00       XwmMenu
 2305  1851   578 tty6     00:00:00         xinitrc.xfce4
 2319  2319   578 tty6     00:00:00           xfbackdrop
 2321  2321   578 tty6     00:00:00           xfce4-panel
=========================

Please examine that the XwmMenu and xinitrc.xfce4 have
the same PID and SID.
However, the xfce-mcs-manager and also other apps (mozilla, xft, xterm)
have different PID and SID. They even do not have TTY.

Continue ...

So I still can not see the way to implement your ideas.
Is it posible to do this from C ?
If yes, then I'll hack the XwmMenu it self.

did you try my suggestion?
please post result of:
  \ps lax

I did.
It did not work.
It killed only xfbackdrop.

As you see on my ps output before (sorry, ps lax is not available yet. Must rebooting to get it :).
only xfbackdrop and xfce4-panel have the parent of xinitrc.xfce4 (the script).
The other XFCE components (xfce-mcs-manager and xfwm) have their own SID and PGID with PID=1 (init).

Also the applications (dfm, xfe, xterm, mozilla) have PGID = 1.

if there have been processes spawned using fork and exec, so they get 1 as PPID, then there is no possibility to identify which PID was their real father.
You either need to keep a list of your spawned processes, or kill them by name (means you're shure that you don't need them)

>> You either need to keep a list of your spawned processes.

Well, then only xfce it self can kill the right processes.
I wonder why it does not.

Anyway ... here is the complete ps -lax if you are still interested.


F   UID   PID  PPID PRI  NI   VSZ  RSS WCHAN  STAT TTY        TIME COMMAND
4  1001   572     1   8   0  2272 1308 pipeli S    tty1       0:00 -bash
4  1001   578     1   9   0  2272 1308 proc_d S    tty6       0:00 -bash
0  1001   684   578   9   0  2028  980 proc_d S    tty6       0:00 /bin/sh /usr/X11R6/bin/startx
0  1001   695   684   9   0  2224  640 proc_d S    tty6       0:00 xinit /home/vec/.xinitrc --
0  1001   708   695   9   0  3408 1452 proc_d S    tty6       0:00 /usr/bin/XwmMenu
0  1001   710   708   8   0  2024  964 proc_d S    tty6       0:00 /bin/sh /etc/X11/xinit/xinitrc.xfce4
1  1001   721     1   9   0 10136 4528 alloc_ S    ?          0:00 xfce-mcs-manager
1  1001   723     1   9   0  8276 4632 alloc_ S    tty6       0:00 xfwm4 --daemon
0  1001   724   710   9   0  9264 4272 alloc_ S    tty6       0:00 xfbackdrop
0  1001   726   710   9   0 10848 6916 alloc_ S    tty6       0:00 xfce4-panel
1  1001   727     1  11   0  5812 2676 end_ki S    tty6       0:00 dfm
0  1001   729     1   9   0  5936 3560 end_ki S    ?          0:00 /usr/X11R6/bin/nedit
0  1001   731     1   9   0  8656 4516 end_ki S    ?          0:00 /usr/X11R6/bin/xfe

hmm, can we make the rule that you want to kill anything startet from bash on tty6?

  kill `ps -lax|grep -v bash|awk '($11=="tty6"){print $3}'`

# works with gawk, but not traditional AT&T awk, please check yourself

Sorry man.
I want to kill any process launched by XwmMenu and it's offspring.

Your solution:
    - kill the X, so the user back to the console.
    - does not kill the X-programs that do not use TTY, but actually the offspring

Thanks.

PS: I can't believe this simple wish is so hard to achieve.


 

Sorry, I had been a bit occupied these days and did not check back on this thread as it needed more time

>I want to kill any process launched by XwmMenu and it's offspring.
>Is it posible to do this from C ?

This simple wish will indeed be hard to achieve and will require some work
The easiest way(s) that I can think of is
1. In C, each process when created writes its pid to a file and on exit removes it from the file (man atexit) ... Most likely you would be kiling the parent using some signal ... in that signal handler, read that file and send kill signals to all processes with the PIDs listed in that file
2. In C, whenever you do a setsid, note down the pid of the group leader and send kills to -pid (man 2 kill)

If these sound reasonable to you, we can discuss them in detail.

sunnycoder, see my comment
  Date: 12/15/2003 11:50PM CET

Dear Sunny and ahoffman.
I nearly give up :)

I sent the problem to xfce-milist.
The developers wonder why do people need those feature
and said to forget it.
They suggested "Don't to use XwmMenu, instead, use kdm, gdm or xdm that kill everything".

I don't like that idea since that mean I have to logout and login again each time I want to change the WM/DE.
But what can I say ... :(

oops ... sorry ahoffmann ... I had lost track of the thread ... will be more careful later...

Kocil, it really is uncommon to kill a process and all its offsprings if you are making an offspring a group leader. It defeats the entire purpose of making a separate group leader.

>> ... if you are making an offspring a group leader.
Not me ... It's them.
I'm the victim. :)

victim? use more reliable and simple tools than xfce*:)
SCNR

No solution for this problem :(
Does anybody complain If I cancel this question ?

yes and no :o)
yes because there is no solution and all possible avenues were exhausted ... I concede that I lost track for a while but others did not
no because we indeed were not much help in the given situation

Go ahead, post in CS for deletion ... no objections from my side