HP 3000 Manuals

MPE V to MPE XL: Getting Started

Lesson 2:  Creating and Displaying Variables 

User created variables must be given values.  Use SETVAR to create and
modify them.  Use SHOWVAR to display them.

They are similar to JCWs, but are more flexible and extensive.  MPE XL
variables can be used interactively in sessions, in jobs, or in programs.
JCWs and variables can be used in both UDCs and command files.

User created variables can contain 32-bit integers, string values,
Boolean values, expressions, or the names of other variables.  Any
process in a job or session can read, change, or delete user created
variables.  They end when the session/job ends.

SETVAR 


The new command SETVAR is used to create variables and to assign values.
Using it, create a variable f to equal the value Fred, a variable _e to
equal the value eTHEL, a variable k to equal the integer 1024, a variable
j to equal the decimal 10.24, and a variable m to equal the Boolean value
TRUE, as follows:
___________________________________________________________________
|                                                                 |
|                                                                 |
|      SETVAR f, "Fred"                                           |
|      SETVAR _e, "eTHEL"                                         |
|      SETVAR k, 1024                                             |
|      SETVAR j, "10.24"                                          |
|      SETVAR m, TRUE                                             |
|                                                                 |
___________________________________________________________________


NOTE  MPE XL cannot evaluate numbers unless they are integers.
      Therefore, you must put quotes around 10.24, treating it as
      alphanumeric data.  Notice, however, that the whole number 1024 and
      the Boolean value TRUE are specified without quotes.


SHOWVAR 

To show that these variables were set, use SHOWVAR:
_____________________________________________________________________
|                                                                   |
|                                                                   |
|      :SHOWVAR                                                     |
|      F = Fred                                                     |
|      _E = eTHEL                                                   |
|      K = 1024                                                     |
|      J = 10.24                                                    |
|      M = TRUE                                                     |
|                                                                   |
_____________________________________________________________________

Entering SHOWVAR alone displays a list of all user created variables
defined during a session, and their values.  The variables are shown in
the order of their creation.

You may also specify one or more specific variables in the SHOWVAR
command:
____________________________________________________________________
|                                                                  |
|                                                                  |
|      :SHOWVAR F,K                                                |
|      F = Fred                                                    |
|      K = 1024                                                    |
|                                                                  |
____________________________________________________________________

Exercises 

2.   Set the variable PI to equal the string value 3.14159, and the
     variable BOND to equal the string value 007.

3.   Display the values of PI and BOND.

MPE/iX 5.0 Documentation