NET/MASTER Network Control Language (NCL) Programmer's Guide

Factors Affecting Panel Description File Location
Working With Panels
106160 Tandem Computers Incorporated 14–17
The Default Search Path The default search path that an NCL process uses to locate a panel description file
affects the panel description file it finds when there is more than one of the same
name. The order of the search path that an NCL process uses to search for any panel
description file is:
1. User panel library, the name of which is defined in your user ID definition record.
2. System panel library, which includes the following:
a. Customized panel library, the location of which is defined in the NonStop
NET/MASTER MS configuration file using the PARAM PNLCUSTSRC
command.
b. Distribution panel library, the location of which is defined in the NonStop
NET/MASTER MS configuration file using the PARAM PNLDISTSRC
command.
3. The distributed panel object file. How you can customize the default panel search
path is discussed later in this section.
There are two consequences of the default search path for an NCL process that
attempts to locate a panel.
First, when the NCL process begins the search for a panel description file on disk, the
NCL process begins by looking in your own user panel library, if present. If you do
not have a user panel library, the NCL process begins the search with the customized
panel library. The NCL process continues the search to the distribution panel library,
if it cannot find an earlier matching name. Finally, if still unsuccessful, NonStop
NET/MASTER MS searches the distributed panel object file.
Second, when a panel description file is preloaded using the SYSPARMS PPRELOAD
command, unless the name of a panel library is specified, the NCL process begins the
search by looking in the customized panel library. The NCL process continues the
search to the distribution panel library, if it cannot find a matching name in the
customized panel library. Finally, if still unsuccessful, NonStop NET/MASTER MS
searches the distributed panel object file.
The NCL process assumes that the first match it finds in the search path is the panel
description file to use. This means if you create a panel description file in the
customized panel library with the same name as a panel description file in the
distribution panel library, the NCL process always uses the panel description file in
the customized panel library.
If an NCL process cannot find a matching name, it raises a run-time error that you can
trap with either the ERROR or PANEL_ERROR error handler. For more on these error
handlers, see Section 7, “Run-Time Error Handling.”