Is There any API in linux to know process ID and it's status

sivareddy_jntu · 08-21-2009, 04:33 AM

Hai All,

I just need an API to know a process ID and it's status,whether it is alive or not.

Any help would be appreciated greatly.

Regards,
-Siva.

jlliagre · 08-21-2009, 04:52 AM

In what language ?

sivareddy_jntu · 08-21-2009, 04:58 AM

hai,
In 'C' Language i need an API to know about process ID and it's status.

Thanks for ur quick response.

Regards,
-Siva.

w1k0 · 08-21-2009, 07:42 AM

Maybe the command ps axu will be sufficient for your needs?

johnsfine · 08-21-2009, 08:01 AM

You may find it easier to get the information you want by opening and reading the "file" /proc/self/status

You can get a sample of the format and some of the available information by typing

Code:

head -n 25 /proc/self/status

That, of course, gives the information about the process running head. If your own program opens and reads that file, it will get the information about itself.

The Linux kernel creates the information in that format as you read /proc/self/status. It is not like an ordinary file with the information sitting around waiting to be read.

jlliagre · 08-21-2009, 08:01 AM

to w1k0: Probably, however "ps" is a command line (shell) API, not C.

I would suggest to travel the /proc directory in C to find out what processes are alive. Be aware though that what you'll find there doesn't represent an API, might be missing if /proc is not mounted, might change from a version to another and from a distribution to another.

To check if a process is still alive while knowing its pid, you can use the kill system call with 0 as second parameter.

chadwick · 08-21-2009, 06:19 PM

Quote:

Originally Posted by sivareddy_jntu

hai,
In 'C' Language i need an API to know about process ID and it's status.

Do you mean that, given a known process ID, you want to determine the status of the process with that ID?