Security

[Walker, Chris]

The only really reliable way to set symbols (as opposed to logicals) for a
subprocess in Quick is to use something like RUN COMMAND 'a_name == "a
value"'.  Once Quick has spawned a subprocess (at which point the parent's
symbol table is inherited), it normally keeps it available for future
commands.  This is much more efficient, and it allows you to "pipe" commands
from Quick to the subprocess.  But it means that you can only rely on
SETSYMBOL if you use it when Quick first starts.

Despite this, it's probably worth using symbols instead of logicals because
they have a lower overhead.

Chris Walker
Tate & Lyle
London


> -----Original Message-----
> From: Chris Sharman [mailto:Chris.Sharman@ccagroup.co.uk]
> Sent: Wednesday, January 19, 2000 9:52 AM
> To: robert.edis@creatcomp.com
> Cc: Chris.Sharman@ccagroup.co.uk; powerh-l@lists.swau.edu
> Subject: RE: Security
> 
> 
> >The environment variables are OK generally but you have to 
> be careful.  I
> >have not had any success setting a variable in one PH 
> program and then using
> >it another under HP/UX and in VMS only logicals in the JOB 
> table seem to be
> >robust; symbols don't work well.
> 
> VMS symbols/logicals are all "robust", but you need to understand the
> environment:
> 
> Process logicals & symbols work well within the process (but 
> note hyphens
> aren't allowed in symbol names). For a subprocess (ie RUN 
> COMMAND, SPAWN, etc),
> only job logicals are shared, but process logicals and 
> symbols are copied from
> the parent to the subprocess when it is spawned. This gives 
> rise to symbols &
> process logicals working well the first time (ie, simple 
> tests), but then the
> subprocess is kept hanging around and is reused as necessary, 
> and changes are
> NOT copied down.
> 
> HP/UX: sounds like you need a real OS ;)
> 
> Regards,
> Chris
> ______________________________________________________________
> _________
> Chris.Sharman@CCAgroup.co.uk		http://www.ccastat.demon.co.uk/
> CCA Stationery Ltd, Eastway, Fulwood, Preston, Lancashire, PR2 9WS.
> = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = 
> = = = = = = =
> Subscribe: "subscribe powerh-l" in message body to 
> majordomo@lists.swau.edu
> Unsubscribe: "unsubscribe powerh-l" in message to 
> majordomo@lists.swau.edu
> This list is closed, thus to post to the list, you must be a 
> subscriber.
> 
= = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
Subscribe: "subscribe powerh-l" in message body to majordomo@lists.swau.edu
Unsubscribe: "unsubscribe powerh-l" in message to majordomo@lists.swau.edu
This list is closed, thus to post to the list, you must be a subscriber.