HP 3000 Manuals

HP ALLBASE/4GL Developer Reference Manual Vol. 2

SELECT Command 

The SELECT command executes one command in a list of commands according
to the value in the communication area field *PASS.

Format 

SELECT command; command;...

Window 


            

Parameters 

command 

The command to be executed.  The command can be any of the following:

   *   ENTER

   *   EXIT

   *   EXTERNAL

   *   MESSAGE

   *   PROCEED

   *   SERIES

   *   TOP

   *   VISIT

   *   ZIP

You must separate the commands in the command list with semicolons.

Description 

The SELECT command executes a specified command from a list of logic
commands.

The value in the communication area field *PASS determines the number of
the command that the SELECT command executes.  If the number in *PASS
does not correspond to a command in the command list, HP ALLBASE/4GL
executes the command in the logic block following the SELECT command.

You must terminate all commands other than the last command in the list
with a semicolon.  If you enter the commands via the SELECT window, the
semicolon terminator is optional.  In this case, HP ALLBASE/4GL inserts
the semicolon automatically if you don't specify it during entry.

You can use the SELECT command in conjunction with a CHECK command.  The
CHECK command sets the content of *PASS, and the SELECT command chooses
the relevant command to execute from the command list.


NOTE  The SELECT command only executes one command.  If you enter more
      than one command in the same field via the window without the
      intervening semicolon, HP ALLBASE/4GL will interpret the commands
      as two separate commands in the selection list.


Example 1 

     5  MOVE * *PASS
     6  SELECT ENTER 5; ENTER 12; ENTER 15; PROCEED main_menu

These commands take the number from the current screen field and execute
the command in the command list that corresponds to that number.  For
example, if the current screen field contains the number 2, HP
ALLBASE/4GL executes the command ENTER 12 since this is the second
command in the command list.

Example 2 

     3  SCREEN get_command
     4  CHECK *S01 *TABLE=commands
     5  SELECT PROCEED command_1; PROCEED command_2; EXIT 
     6  MESSAGE reenter
     7  ENTER 3

These commands accept input from the screen get_command and validate the
data against the table commands.  The CHECK command places its result
into *PASS. The SELECT command then uses this value to execute the
appropriate HP ALLBASE/4GL command from the command list.  If the value
in *PASS is not between 1 and 3, HP ALLBASE/4GL displays the message
reenter.

MPE/iX 5.0 Documentation