HP 3000 Manuals HP 3000 Manuals
Issuing Commands Through UDCs
A user-defined command (UDC) saves time and reduces errors. It allows a
commonly used command string or multiple command strings to be issued
with a single entry.
Creating a UDC File
A UDC file is a specially identified file containing one or more UDCs.
Each UDC is composed of a unique name, required and optional parameter
specifications, selected options controlling its execution, and one or
more command lines. In a UDC file, each UDC is separated from the next
by a line of one or more asterisks beginning in column 1. You can use
any editor to create a UDC file. The following example shows multiple
UDCs in a single file.
SJ
OPTION LOGON
SHOWJOB
*****
LF
LISTFILE
*****
ABXYZ A,B=B
OPTION LIST
RUN !A.PUB.SYS
RUN !B.PUB.SYS
RUN XYZ
*****
CF1
CMDFL1
*****
To distinguish a UDC file from other files, it must be cataloged, using
the SETCATALOG command. This process identifies the contents of the file
as UDCs, so that any UDC name within the file is interpreted as a command
by the CI. UDC files can be created at the user level, the account level,
or the system level. UDCs can be added to or deleted from an existing
UDC file, but must be uncataloged first. (Refer to the self-paced
tutorial Using the 900 Series HP 3000: Fundamental Skills (32650-60037)
for details about cataloging, adding to, and deleting from a UDC file.)
Executing a UDC
The UDC file in the preceding example contains four UDCs. The user can
enter a UDC name and parameters, if appropriate, at the CI prompt to
execute its associated routine. For example, by entering LF at the CI
prompt, the UDC named LF is executed. Its associated commands execute
the LISTFILE command.
When executing a command, the CI first searches cataloged UDC files for a
UDC name that matches the command string. UDC files are searched in the
following sequence:
1. User-level UDCs.
2. Account-level UDCs.
3. System-level UDCs.
If the specified command does not match a UDC name, the built-in MPE/iX
commands are searched. UDCs, therefore, provide a method of superceding
standard MPE/iX commands.
[REV BEG]
NOTE When a UDC or command file is used to invoke a program while in
BREAK from another program invoked from within a UDC or command
file, MPE/iX returns CIERR 9065.
[REV END]
Specifying UDC Options
Several options are available to control UDC processing. These options
are especially useful to programmers to allow or prohibit certain
features. (Refer to the self-paced tutorial Using the 900 Series HP
3000: Fundamental Skills (32650-60037) for a detailed description of
each UDC option.)
LIST or NOLIST Controls the display of each command image as it is
executed.
HELP or NOHELP Controls the ability to display the contents of the
UDC in help mode.
BREAK or NOBREAK Controls the ability to stop execution of a UDC.
LOGON or NOLOGON Controls the automatic execution of a UDC at logon.
RECURSION or Controls the search for UDCs called from another UDC.
NORECURSION
PROGRAM or Controls the ability of a UDC to be executed from a
NOPROGRAM program.
The contents of a UDC can be listed as each command is executed using the
LIST option. All or any portion of the UDC can be kept from listing by
specifying the NOLIST option. The NOLIST option is often used to
eliminate unnecessary display or to maintain security. The NOHELP option
similarly limits the listing of a UDC's contents within the Help
facility.
The NOBREAK option limits the ability of the user to break the processing
of UDC commands. This option is often used to protect a series of
processing steps or to ensure that an error procedure is completed. The
NOBREAK option is also used as a security measure by keeping the user
from gaining control of the CI by breaking a procedure.
UDCs can be invoked automatically when the user logs on to the system if
the LOGON option is set. This feature can be used to restrict users to a
particular application environment or to automatically perform a routine
commonly performed at the beginning of a session. In the previous
example, the first UDC (SJ) contains the logon option. This UDC is
performed automatically when you log on. Your logon is followed
immediately by the list of all active jobs, the output of the SHOWJOB
command. The CI prompt is displayed following the job display. Note
that only one UDC in the UDC file can contain the LOGON option.
The search for a UDC starts at the beginning of the search sequence to
the point where a matching UDC name is encountered. If one UDC is called
from another, the search for the second UDC begins where the previous
search ended. The RECURSION option provides a method of specifying that
the search must start at the beginning of the standard search sequence.
The NOPROGRAM option controls UDC calls from an application program. A
UDC can be executed through the HPCICOMMAND intrinsic if the PROGRAM
option is specified in the UDC. This option is often used to control
execution of UDCs and built-in commands that have the same name.