simple script

spx2 · 07-09-2006, 01:11 PM

i want to make a bash script
to execute an application for n seconds and
then stop it,then execute it again for n seconds
and so on.
how can i approach this problem ?

macemoneta · 07-09-2006, 01:46 PM

You can run the program as a background job, sleep for the interval you want, then kill the process. The special variable '$!' contains the process number for the last background job submitted.

spx2 · 07-09-2006, 01:52 PM

so you suggest something like

bg application
$pidapp=$!
fg application
sleep n seconds
kill -SIGTERM $pidapp

?

please tell me correct syntax

theNbomr · 07-09-2006, 02:28 PM

This seems to do it.

Code:

#! /bin/bash

while [ 1 ] ;
do
        $1 &
        repeatpid=`jobs -p`;
        echo "Current job: $repeatpid";
        sleep 10;
        kill -9 $repeatpid;
done

--- rod.

spirit receiver · 07-09-2006, 02:30 PM

I'd suggest

Code:

while true; do timeout -s TERM n application; done

spx2 · 07-09-2006, 02:41 PM

bash: timeout: command not found

this is the error i get.
i'm using Vector Linux SOHO 5.1 wich has allot if not all linux
bash utils or usual commands.
i am root so i have access to all of them.

spx2 · 07-09-2006, 02:42 PM

bash: timeout: command not found

this is the error i get.
i'm using Vector Linux SOHO 5.1 wich has allot if not all linux
bash utils or usual commands.
i am root so i have access to all of them.

spirit receiver · 07-09-2006, 03:02 PM

Oh, you're right. I thought it was standard, but it belongs to a package called netatalk here. So you're probably better off with theNbomr's script, only that it's a little easier to get the PID of the backgound process in Bash:

Code:

while true; do application& sleep n; kill -s TERM $!; done

Edit: OK, now I've got it.

Gins · 07-10-2006, 06:14 AM

Using the vi editor, I wrote the following file which has the name 'kill100'.
---------------------------------

#! /bin/bash

while [ 1 ] ;
do
$1 &
repeatpid=`jobs -p`;
echo "Current job: $repeatpid";
sleep 10;
kill -9 $repeatpid;
done
------------------------------------

When I ran the program, it was a non-stopping output. Please read the following:

[nissanka@c83-250-110-112 ~]$ vi kill100
[nissanka@c83-250-110-112 ~]$ chmod 755 kill100
[nissanka@c83-250-110-112 ~]$ ./kill100
Current job: 7928
./kill100: line 12: kill: (7928) - No such process
Current job: 7931
./kill100: line 12: kill: (7931) - No such process
Current job: 7934
./kill100: line 12: kill: (7934) - No such process
Current job: 7937
./kill100: line 12: kill: (7937) - No such process
Current job: 7940
./kill100: line 12: kill: (7940) - No such process
Current job: 7943
./kill100: line 12: kill: (7943) - No such process
Current job: 7946

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

How can I terminate it?
I think the following line will help to terminate the program.
while true; do application& sleep n; kill -s TERM $!; done

Where shall I place it on the program?

theNbomr · 07-10-2006, 08:50 AM

The script runs forever. To kill it, type Control-C from the script's terminal, or use ps to find it's pid, and issue a 'kill -9' to it. However, in your example, you failed to give the script the name of any program to run. It was written with the intent to provide the program name as a commandline argument.

Code:

[nissanka@c83-250-110-112 ~]$ ./kill100 yourProgram

Your specification in post #1 did not specify that it should terminate.

--- rod.

Gins · 07-10-2006, 12:44 PM

Thanks theNbomr for taking time to reply. I am running the wordprocessor program 'Open office'.

Let us say that I want to kill it or rather discontinue it using this program. How do I find the name of the program?

The following didn't work. I just wrote the words 'openoffice' and 'open office'.

[nissanka@c83-250-110-112 ~]$
[nissanka@c83-250-110-112 ~]$ ps
PID TTY TIME CMD
7845 pts/1 00:00:00 bash
15327 pts/1 00:00:00 ps
[nissanka@c83-250-110-112 ~]$ ./kill100 open office
Current job: 15329
./kill100: line 12: kill: (15329) - No such process
Current job: 15333
./kill100: line 12: kill: (15333) - No such process
Current job: 15337
[nissanka@c83-250-110-112 ~]$ ./kill100 openoffice
./kill100: line 8: openoffice: command not found
Current job: 15342
./kill100: line 12: kill: (15342) - No such process
./kill100: line 8: openoffice: command not found
Current job: 15345
./kill100: line 12: kill: (15345) - No such process
./kill100: line 8: openoffice: command not found
Current job: 15348
./kill100: line 12: kill: (15348) - No such process

theNbomr · 07-10-2006, 01:20 PM

On my system, OpenOffice Writer is called oowriter. It is installed in /usr/bin on my system, so it is found in my usual PATH. You should try

Code:

kill100 oowriter

If that fails, use

Code:

find / -name oowriter -print

to find out where your OpenOffice word processor is. Then use that to specify the full filespec to your kill100 script. Or, use the desktop menu editor to inspect the menu item for OpenOffice, to locate the binary filename, or use 'locate oowriter' if you have the slocate database installed. It may take longer than 10 seconds for the program to fully initialize, so killing it before then just might cause Bad Things to happen. Killing a word processor ungracefully like that is probably not the ideal practice, anyway. Why don't you try this experiment using something a little less dramatic, like, say 'xterm'?

--- rod.

Gins · 07-10-2006, 02:04 PM

Thanks theNbomr for the reply.

The command just went on opening a blank page of open office. Why was that? I just closed the shell to avoid creating more empty pages of open office. Afterwards, I closed all the blank pages one by one.

[nissanka@c83-250-110-112 ~]$ ./kill100 oowriter
Current job: 16184
./kill100: line 12: kill: (16184) - No such process
Current job: 16207
./kill100: line 12: kill: (16207) - No such process
Current job: 16230
./kill100: line 12: kill: (16230) - No such process
Current job: 16253
./kill100: line 12: kill: (16253) - No such process
Current job: 16276
./kill100: line 12: kill: (16276) - No such process
Current job: 16299
--------------------------------------------------

[nissanka@c83-250-110-112 ~]$ su root
Password:
[root@c83-250-110-112 nissanka]# find / -name oowriter -print
/usr/bin/oowriter
[root@c83-250-110-112 nissanka]#

Gins · 07-10-2006, 02:06 PM

[root@c83-250-110-112 nissanka]# slocate oowriter
warning: slocate: warning: database /var/lib/slocate/slocate.db' is more than 8 days old
/usr/share/doc/mandriva/en/Starter/Starter.html/images/oowriter-bulletlist-icon.png
/usr/share/doc/mandriva/en/Starter/Starter.html/images/oowriter-numberedlist-icon.png
/usr/share/doc/mandriva/en/Starter/Starter.html/images/oowriter-page-styles.png
/usr/share/doc/mandriva/en/Starter/Starter.html/images/oowriter-stylist-icon.png
/usr/share/mimelnk/application/x-oowriter.desktop
/usr/bin/oowriter
[root@c83-250-110-112 nissanka]#

[root@c83-250-110-112 nissanka]# locate oowriter
warning: locate: warning: database /var/lib/slocate/slocate.db' is more than 8 days old
/usr/share/doc/mandriva/en/Starter/Starter.html/images/oowriter-bulletlist-icon.png
/usr/share/doc/mandriva/en/Starter/Starter.html/images/oowriter-numberedlist-icon.png
/usr/share/doc/mandriva/en/Starter/Starter.html/images/oowriter-page-styles.png
/usr/share/doc/mandriva/en/Starter/Starter.html/images/oowriter-stylist-icon.png
/usr/share/mimelnk/application/x-oowriter.desktop
/usr/bin/oowriter
[root@c83-250-110-112 nissanka]#

How do I use the Xterm? I have never used it.

spirit receiver · 07-10-2006, 02:15 PM

oowriter is just a little script that starts another program and exits. And I don't see much sense in using the script "kill100" with oowriter.