HP 3000 Manuals HP 3000 Manuals
Commands and Parameters
MPE/iX commands tell the computer to perform a specific function. The
parameters you enter for each command tell the computer to perform the
function in a specific way. MPE/iX uses four classifications of
parameters:
* Required parameters.
* Optional parameters.
* Keyword parameters.
* Positional parameters.
These four classifications of parameters are briefly defined below. To
understand the command syntax diagrams, refer to the Conventions pages in
the front of this manual.
Required Parameters
If a command has any required parameters, they must be entered or MPE/iX
displays an error message. In the syntax diagrams for each command in
this chapter, required parameters are either surrounded by no other marks
or by braces { }. In the following example, since myfile is not
surrounded by any marks, it is a required parameter:
BUILD myfile
In some cases, you must select one parameter from a list of two or more
parameters. In the following example, you must provide either a job
number or a session number since these parameters are surrounded by
braces:
ALTJOB {#Jnnn}
{#Snnn}
Optional Parameters
If a command has any optional parameters, you can either specify or
ignore them, depending upon how you want the command to execute. In the
syntax diagrams for each command in this chapter, optional parameters are
surrounded by brackets [ ]. If you ignore optional parameters, MPE/iX
uses the system-defined default values for each parameter. In the
following example, [;PASS] is an optional parameter since it is
surrounded by brackets:
NEWGROUP groupname [;PASS=[password]]
Positional Parameters
The meaning of a positional parameter depends upon its position
(location) in the parameter list. In the syntax diagrams for each
command in this chapter, positional parameters are separated from each
other by a comma (,). If you omit a positional parameter from the list,
you must provide the comma placeholder that would normally precede that
parameter. In the following example, the subparameters of the REC
parameter of the BUILD command can be treated as positional parameters:
BUILD filename;REC=128,1,F,ASCII
If you choose to use the system-defined default value F, you need not
specify it, but you must hold the position with a comma:
BUILD filename;REC=128,1,,ASCII
Keyword Parameters
A keyword parameter denotes the meaning or value of a given parameter.
In the syntax diagrams for each command in this chapter, keyword
parameters appear in uppercase (CAPITAL) letters (although you may enter
them in either uppercase or lowercase) and are preceded by a semicolon
(;). In the following example, REC is a keyword parameter:
BUILD filename;REC=128,1,F,ASCII
Refer to the section "Combining Positional/Keyword Parameters," below,
for additional information.