{INCLUDE _LOGOS_C.HTM}

Opening mv/WEB Files in Named Common

Documentation for build 2.0.0.132
April 23, 1999

mv/Web has a number of restrictions on the use of mv/BASIC file variables. On host systems that support named common there is a technique that can be used to pre-open application data files and then easily access these data files from within an application. Setting up this involves several steps:

Defining a Named Common INCLUDE

The first step that you should take is to build an INCLUDE item that contains the file variables for a particular application. This include item should be stored in a standard source code file (not in a source code file that is used by PLZ) and probably in the same source code file that contains other mv/BASIC source code used by your application. Here is an example include that defines five file variables:

BP AR.FILES.INCLUDE


      REM Include for named common file variables for application AR
*
*
*
      COMMON /ARFILES/ CUST.FILE
      COMMON /ARFILES/ INV.FILE
      COMMON /ARFILES/ CTRL.FILE
      COMMON /ARFILES/ INDEX.FILE
      COMMON /ARFILES/ CUST.XREF.FILE

Defining an INIT Subroutine

After you have defined a named common INCLUDE, you need to write a subroutine to open these files.

BP AR.FILES.OPENSUB


      SUBROUTINE AR.FILES.OPENSUB
*
*
*
      INCLUDE BP AR.FILES.INCLUDE
*
      OPEN 'CUSTOMERS' TO CUST.FILE      ELSE STOP 201,'CUST.FILE'
      OPEN 'INVOICES'  TO INV.FILE       ELSE STOP 201,'INVOICES'
      OPEN 'CTRL'      TO CTRL.FILE      ELSE STOP 201,'CTRL'
      OPEN 'INDEX'     TO INDEX.FILE     ELSE STOP 201,'INDEX'
      OPEN 'CUST.XREF' TO CUST.XREF.FILE ELSE STOP 201,'CUST.XREF'
*
      RETURN

After you write this subroutine, compile it with the standard system BASIC (or COMPILE) verb and catalog it so that it can run within the PICLAN-IP account.

Setting up PicLan-IP so that the INIT Subroutine will be Called at Startup

You can then setup the PicLan-IP server so that your initialization subroutine is called by adding the following line to the PLIP.CTRL CONFIG item:

PLIP.CTRL CONFIG


...
INIT SUB=AR.FILES.OPENSUB
...

If you have multiple web applications that need unique file blocks, you can call more than one initialization subroutine in this manner. Just be sure to use different names for the named common blocks with each application.

Using the Open Files Within an mv/Web Application.

Your mv/Web application can use these file variables by simplying INCLUDING the pre-built include item and then using the file variables directly with file I/O statements:

      _SUBROUTINE WEBSUB
*
*
*
      INCLUDE BP AR.FILES.INCLUDE
*
...
      READ CUST.REC FROM CUST.FILE . CUST.ID ELSE
...

Other Issues Dealing with Named Common File Usage

If you use these techniques, you need to insure several things:

Make sure that file opens suceed. If they fail, then the web server will not start.
If you need to change the file opens, move files, or whatever, you can use the PLIP-RESTART command to cycle the web server processes so that your init subroutine re-executes.