Defunct Process

[zap_2]

Hi Unix Gurus,

Can ordinary users produce defunct process?
Thanks in advance.....

[Steven E. Protter]

Yes.

They merely need to have minimal programming skills and be not careful. Usually however, root can kill these processes.

SEP

[Arunvijai_4]

Yes, Anyone can create defunct process.

-Arun

[zap_2]

Can any one show me how to create defunct process?Thanks in advance ...

[Muthukumar_5]

Yes. Simple coding will make process like that. Applications which is running in normal user will create defunct process also.

hth.

[Arunvijai_4 · Accepted solution]

Here is a small C code to create defunct,

#include
main()
{
int pid;
pid=fork(); /* Duplicate */
if (pid!=0) /* Branch based on return value from fork() */
{
while (1)
sleep(1000);
}
else
{
exit(42);
}
}

[root@mysystem tmp]# gcc -o fork fork.c
[root@mysystem tmp]# ./fork &
[1] 6823

[root@mysystem tmp]# ps
PID TTY TIME CMD
6764 pts/0 00:00:00 bash
6823 pts/0 00:00:00 fork
6824 pts/0 00:00:00 fork
6825 pts/0 00:00:00 ps

[Arunvijai_4]

I tried in Linux, not on HP-UX since i dont have a compiler installed in my HP-UX. Anyways, it should work.

-Arun

[zap_2]

Hi Arun,
How to compile your script in hpux?

[Arunvijai_4]

# cc -o fork fork.c
# fork &
# ps

-Arun

[zap_2]

# cc fork fork.c
cc: warning 485: Can't open "fork.c".

[Arunvijai_4]

It should be # cc -o fork fork.c, assuming that you have fork.c in your current directory. Otherwise, you need to give full path to fork.c

-Arun

[Raj D.]

Hi Zap ,

Try ,

# cc fork.c -o fork

-o defines the output compiled file.
For details check # man cc


Cheers,
Raj.

[zap_2]

many thanks unix gurus .........

[Vibhor Kumar Agarwal]

Defunct process is a process which has terminated but the signal hasn't been send to the parent.

So it has nothing to do with a user.
Either you can create it or you run an application which is not programmed correctly.