opening pipe to process already running

Eugene Tsyrklevich eugene at
Fri Jun 9 18:00:51 CDT 2000

On Fri, Jun 09, 2000 at 11:20:46AM -0700, John R. Comeau wrote:
> ~sdpm~
> I'm running on SunOS5.5.1, and I'd like to be able to open a pipe to a
> process that's already running.  That is, suppose I have a 'daemon'
> process that runs all the time.  Then periodically another process
> will run and communicate with the daemon process over a Unix pipe.  I
> don't even know if this is possible in Unix; all the Perl examples
> I've seen deal with pipes between parent and child processes.
> However, in my case the processes do not have a parent-child
> relationship.
> What I currently have implemented is that the daemon process looks for
> special files created by the periodic processes.  However, this is
> messy since those files may be left over if one of the processes is
> killed before it can delete them.
> I know that you can send a signal to a running process, but how do you
> open a pipe to it?
> I guess another possibility is that I could use a FIFO file (named
> pipe) instead of the normal files I currently have implemented.  But
> still that seems messy.

if your processes are unrelated than you have to use FIFOs for your pipes IPC
see  for more details

my personal favorite is sockets.. another alternative (which is probably the messiest) is shared memory


Eugene Tsyrklevich
Security Architects, Inc.

The posting address is: san-diego-pm-list at

List requests should be sent to: majordomo at

If you ever want to remove yourself from this mailing list,
you can send mail to <majordomo at> with the following
command in the body of your email message:

    unsubscribe san-diego-pm-list

If you ever need to get in contact with the owner of the list,
(if you have trouble unsubscribing, or have questions about the
list itself) send email to <owner-san-diego-pm-list at> .
This is the general rule for most mailing lists when you need
to contact a human.

More information about the San-Diego-pm mailing list