samba - Apr 1998 - Triggering processes through Samba

Hi,

I need to upload data from a barcode scanner into a Progress database 
on UNIX. The barcode reader is attached to a PC. We have set it up in 
this way that the barcode reader creates a file in a directory shared 
by the PC and an HP box. A simple daemon on the HP scans the directory 
and triggers a program to upload the data whenever it finds a file in 
that directory.

I was wondering if there isn't a more direct way of triggering a 
process through Samba, so that I can get rid of the daemon.
Thanks for your help.


Koen Dejonghe
QAD Service Line
Origin International - Brussels
tel. +32 (0)2 712 3668

On Mon, 6 Apr 1998 samba@samba.anu.edu.au wrote:
> From: "Dejonghe, Koen" <Koen.Dejonghe@be.origin-it.com>
> To: "'samba@samba.anu.edu.au'"
<samba@samba.anu.edu.au>
> Subject: Triggering processes through Samba
> 
> I was wondering if there isn't a more direct way of triggering a 
> process through Samba, so that I can get rid of the daemon.
> Thanks for your help.
You could try creating a named pipe under Unix and having your
barcode reader write data to it.

e.g.
$ mknod pipe p
$ ls -l pipe
prw-r--r--   1 brett    sct            0 Apr  6 14:47 pipe
$ cat pipe

Meanwhile over on the PC...

D:\tmp>dir pipe
 Volume in drive D is brett
 Volume Serial Number is 0994-05F2

 Directory of D:\tmp

06/04/98  13:47                      0 pipe
               1 File(s)              0 bytes
                            122,486,784 bytes free
D:\tmp>echo hello > pipe

Then back at the Unix machine:

$ cat pipe
hello 
$ 

Just like magic...
> Koen Dejonghe
Brett Worth

Koen,
> I was wondering if there isn't a more direct way of triggering a 
> process through Samba, so that I can get rid of the daemon.
> Thanks for your help.
There are two possibilities.  First, the 'postexec' and 'root
postexec'
parameters let you specify a command to run when a client disconnects from
a resource.  This might solve your problem.  Remember that most clients do
not just disconnect when you are done-- you will have to do this
explicitly, or set 'dead time' to be just a minute.  This would cause
Samba to automatically disconnect clients after just a minute of
inactivity, trigerring the 'postexec' and 'root postexec'
commands.

Another possibility is 'magic script'.  The 'magic script'
command lets
you specify a file that, when closed, will be executed.  It gives you a
(rather hacky) way to send a shell script to the server.  You could create
a script to copy a shell script which would then trigger the gather of
your barcode data.

A third (I just thought of this one), rather extreme possibility would be
to modify the 'magic script' command to allow you to specify an
arbitrary
command that will be executed when an arbitrary filename is closed.  This
might not be too difficult, but would involve dipping into the innards of
Samba :) 

 later,
 -john.

---------------------------------------------------------------------
John D. Blair          (sys|net)admin, the university computer center
mailto:jdblair@uab.edu                    u. of alabama at birmingham
phoneto:(205) 975-7123                        (my other car is a cdr)
---------------------------------------------------------------------

on 6 Apr 1998, <Koen.Dejonghe@be.origin-it.com> wrote:
> I was wondering if there isn't a more direct way of triggering a
> process through Samba, so that I can get rid of the daemon. Thanks 
> for your help.
Try sending a Winpopup containing the data to the HP. Use the 
'message command =' parameter of smb.conf to specify the program to 
process it.

Ludolf