Parameters within Syntax

MPE/iX commands instruct the system to perform a desired function. If y ou include parameters with the command before y ou enter it, the parameters speci￿cally instruct the system ho w it should perform the command function.

There are three types of parameters:

required optional positional

Required parameters

You must enter all required parameters; otherwise, MPE/iX displa ys an error message when you enter the command. In the syn tax diagrams for eac h command, either braces { } or no marks surround required parameters.

In the following example, my￿le is a required parameter because no marks surround it:

BUILD my￿le

Anything italicized, suc h as my￿le , is a representational name or v alue and must be replaced with an actual name or v alue.

Sometimes you must select one parameter from t wo or more parameters. In the following example, y ou must provide either a job n umber or a session number because braces surround these parameters:

￿ #Jnnn ￿

ALTJOB #Snnn

Optional parameters

You can either specify or ignore optional parameters, if an y, depending on how you want the command to execute. In the syn tax diagrams for eac h command, brackets [ ] surround optional parameters. If y ou ignore optional parameters, MPE/iX uses the system-de￿ned default v alues for each parameter.

1-2 Introduction to Command Parameters