how to get a process status according to process name in the kernel?

[liudonghua123]

Hi,
I am writting a kernel module which needs to get a process status(running or not) according to its name(I know the name of the executive file)
Thanks in advance!

[bsdtux]

If it is a particual process that will never change get the pid location and just do a check for if the process.pid exists or not. If the service is off you should not see that file. If it is active you should be able to read that file and get the process id.

Here is an example of my apache server

[root@prodsimsfe logs]# ls
access_log                    jk-runtime-status.2133        mod_jk.log
cor_access_log                jk-runtime-status.2133.lock   ssl_access_log
error_log                     jk-runtime-status.27178       ssl_error_log
httpd.pid                     jk-runtime-status.27178.lock  ssl_request_log
jk-runtime-status.11341       jk-runtime-status.29142
jk-runtime-status.11341.lock  jk-runtime-status.29142.lock
[root@prodsimsfe logs]# cat httpd.pid 
2133
[root@prodsimsfe logs]# ps -ef | grep httpd
root      2133     1  0 Jan18 ?        00:01:21 /usr/local/apache2/bin/httpd
daemon    7434  2133  0 Jan28 ?        00:00:00 /usr/local/apache2/bin/httpd
daemon    7503  2133  0 Jan28 ?        00:00:00 /usr/local/apache2/bin/httpd
daemon   30301  2133  0 00:03 ?        00:00:01 /usr/local/apache2/bin/httpd
daemon   30374  2133  0 00:39 ?        00:00:00 /usr/local/apache2/bin/httpd
daemon   30416  2133  0 00:53 ?        00:00:00 /usr/local/apache2/bin/httpd
daemon   30431  2133  0 01:00 ?        00:00:00 /usr/local/apache2/bin/httpd
daemon   30472  2133  0 01:10 ?        00:00:00 /usr/local/apache2/bin/httpd
daemon   30524  2133  0 01:36 ?        00:00:00 /usr/local/apache2/bin/httpd
daemon   30535  2133  0 01:40 ?        00:00:00 /usr/local/apache2/bin/httpd
daemon   30537  2133  0 01:41 ?        00:00:00 /usr/local/apache2/bin/httpd
daemon   30538  2133  0 01:41 ?        00:00:00 /usr/local/apache2/bin/httpd
daemon   30612  2133  0 02:09 ?        00:00:00 /usr/local/apache2/bin/httpd
root     30651 30626  0 02:12 pts/0    00:00:00 grep httpd
[root@prodsimsfe logs]#

Here you can see that the pid file gave me the parent process id.