Kill an specific process ID using the KILL and GREP commands

Shell Programming and Scripting
1

Good afternoon

I need to KILL a process in a single command sentence, for example:

kill -9 `ps -aef | grep 'CAL255.4ge' | grep -v grep | awk '{print $2}'`

That sentence Kills the process ID corresponding to the program CAL255.4ge.

However it is possible that the same program CAL255.4ge is executed by 2 different users ID, for example:

/nfs/nfs3/fuentes/per>bgr
Procesos ejecutandose en este momento
-------------------------------------
usuario         id      hora            proceso         cola    code    inst
wilruiz0        401506  16:13:07        CAL224.4ge              203     Vid
wilruiz0        770282  16:16:49        CAL227.4ge              203     Gen
wilruiz0        880676  16:16:51        CAL255.4ge              203     Gen
wilruiz0        995572  16:16:47        CAL224.4ge              203     Gen
wilruiz0        1122314 16:16:37        CAL271.4ge              203     Gen
wilruiz0        1224878 16:13:10        CAL227.4ge              203     Vid
/nfs/nfs3/fuentes/per>ps -aef | grep wilruiz2
wilruiz2  385238 1204422   0 12:37:59 pts/28  0:00 -ksh
wilruiz2  401506       1   6 16:13:07 pts/28  0:05 CAL224.4ge 92793345 203
wilruiz2  880696       1   7 16:16:51 pts/11  0:01 CAL255.4ge 92793345 203
wilruiz2  634998 1073300   0 16:12:58 pts/28  0:00 CAR_main.4ge
wilruiz2 1073300  385238   0 16:12:43 pts/28  0:00 INSUNIX.4ge
wilruiz2 1224878       1   3 16:13:10 pts/28  0:03 CAL227.4ge 92793345 203
/nfs/nfs3/fuentes/per>ps -aef | grep wilruiz0
wilruiz0  602116  733346   1 16:27:54 pts/11  0:00 grep wilruiz0
wilruiz0  733346  798882   1 12:37:33 pts/11  0:00 -ksh
wilruiz0  770282       1   8 16:16:49 pts/11  0:01 CAL227.4ge 92793345 203
wilruiz0  844006  733346  22 16:27:53 pts/11  0:00 ps -aef
wilruiz0  880676       1   7 16:16:51 pts/11  0:01 CAL255.4ge 92793345 203
wilruiz0  995572       1  11 16:16:47 pts/11  0:02 CAL224.4ge 92793345 203
wilruiz0 1122314       1  43 16:16:37 pts/11  0:12 CAL271.4ge 92793345 203

There are 2 users

wilruiz0

and

wilruiz2

So I need to tell the UNIX to KILL the process, specifying both the PROGRAM NAME and the USERID.

I guess that would mean to improve the GREP sentence to search for 2 string patterns instead of one.

That would be:

kill -9 `ps -aef | grep -i -e 'CAL255.4ge' -e 'wilruiz0' | grep -v grep | awk '{print $2}'`

It is not working because it is searching for the patterns as an OR instead of AND where the 2 strings patterns are needed to meet.

Please help.

2

Try:

kill -9 $(ps -aef | grep 'CAL255.4ge' | grep 'wilruiz0' | grep -v grep | awk '{print $2}')
1 Like
3

How about using -u param of ps and here I combine two greps and awk into 1 awk script:

kill -9 `ps -fu wilruiz0 | awk '/[C]AL255.4ga/ {print $2}'`

You should try kill -15 before using -9 as this allows the program to exit cleanly (close and flush file buffers and the like).

Edit: Also if no processes are found you probably want to avoid calling kill without a PID
One nice solution is to use xargs (if it supports the no run option):

ps -fu wilruiz0 | awk '/[C]AL255.4ga/ {print $2}' | xargs --no-run-if-empty kill -9
1 Like
4

If your system has it (I believe most do), just use pkill:

pkill -9 -u wilruiz0 '^CAL255\.4ge$'

I have backslash escaped the dot so that it is no longer a wildcard, but a literal dot. Also, I have anchored the expression to preclude substring matches. The chances that the more permissive pattern used throughout this thread will have an unfortunate effect is most likely negligible, but I draw attention to it for completeness' sake.

Regards,
Alister

---------- Post updated at 06:00 PM ---------- Previous update was at 05:57 PM ----------

Depending on the platform, that may not be an option. From a *BSD ps:

Regards,
Alister

1 Like
5

Don Cragun, thanks for your reply, i have a question, why the usage of the command :

grep -v grep

Thanks in advance for your help.

6

If the ps in Don's pipeline obtains the process listing after the grep processes in the pipeline have been created, the pid of grep 'CAL255.4ge , if run by wilruiz0, will be part of the result. The grep -v grep filters it out.

However, since by the time that kill is invoked the grep processes are gone, it's highly unlikely that the pid will be valid (highly unlikely, but it's not impossible that another process could have been created with that same pid).

Regards,
Alister

1 Like
7

The

grep -v grep

gets rid of the grep commands in the ps output that are used to search for the user and command names.

1 Like