REXX Tips & Tricks, Version 2.80


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Example for using REXX programs in the CONFIG.SYS



A REXX program called from within the CONFIG.SYS is always called after 
loading all drivers. So, if you want to use a REXX program to change one 
or more DEVICE or BASEDEV statements (or a file used by a device driver) 
in the CONFIG.SYS while booting the workstation, you must use a 
2-step-method. 
Here's an example: Some time ago a CompuServe forum member said he wanted 
to change the file PROTOCOL.INI in respect to the input of an user while 
OS/2 was booting. (PROTOCOL.INI is an ini file used by a device driver 
necessary for the Network support). 
I suggested to call the REXX program below in the CONFIG.SYS for this 
purpose (see Calling REXX programs in the CONFIG.SYS on how to call a REXX 
program in the CONFIG.SYS). This program uses a status file and an 
additional boot process to change the configuration on the fly. 
The advantage of this method in contrast with using OS/2's ALT-F1 feature 
to perform maintenance at bootup: 
It runs not only on WARP 3, but also under OS/2 versions prior to WARP; 
there's no overhead and you only have to maintain one configuration. 

 
/* REXX program which can be called in the CONFIG.SYS to get some     */
/* input from the user, check the current configuration against the   */
/* user input, and change the configuration and reboot the            */
/* workstation with the changed configuration if necessary.           */
/*                                                                    */
/* Note that you can use this method also to change some lines in     */
/* your CONFIG.SYS.                                                   */
/* Note further, that you can also replace the code to get the user   */
/* input with some code to automatically get the needed configuration.*/
/*                                                                    */
/* You can also use the routine Getkey in programs called in the      */
/* CONFIG.SYS.                                                        */
/*                                                                    */
/* (c) 1996 Bernd Schemmer, Germany, EMail: 100104.613@compuserve.com */
/*                                                                    */

                    /* install an error handler for user breaks       */
  SIGNAL ON HALT Name UserBreak

                    /* name of the status file for the current boot   */
                    /* process. If this file exists, this is the      */
                    /* second boot, if not it's the first.            */
  statusFile = "C:\BOOTSEM"

  if stream( statusFile, "c", "QUERY EXISTS" ) = "" then
  do
                    /* first boot                                     */

                    /* load the necessary REXXUTIL function(s). Note  */
                    /* that you CANNOT use SysLoadFuncs!!!            */
    call rxFuncAdd "SysGetKey", "REXXUTIL", "SysGetKey"

                    /* get the user input                             */
    call CharOut, "Which PROTOCOL.INI do you want? Press A or B ->> "
    do forever
      userInput = translate( SysGetKey( "NOECHO" ) )
      if UserInput = "A" | UserInput = "B" then
        leave
      else          /* invalid user response - ring the bell          */
        call CharOut , "07"x
    end /* do forever */

    call LineOut , UserInput


                    /* check the configuration, in this example:      */
                    /* check if the existing PROTOCOL.INI is correct  */
    call LineOut , "Checking the configuration. Please wait ..."

                /* ... insert the code to check the configuration ... */
                /* set ConfigurationOK to 1 if PROTOCOL.INI is okay   */

    if ConfigurationOK = 1 then
    do
                    /* the current configuration is okay              */
                    /* continue with the boot process                 */

      call LineOut, "The current configuration is okay." ,
                    "Boot process continues ..."

    end /* if ConfigurationOK = 1 then */
    else
    do
                    /* the current configuration is NOT okay          */

      call LineOut, "The current configuration is NOT okay." ,
                    "Now changing the configuration ..."


                    /* correct the configuration, in this example:    */
                    /* replace the PROTOCOL.INI                       */

                /* ... insert the code to change the configuration ...*/

                    /* now create the status file                     */
      call LineOut statusFile, "We need a second boot ..."

                    /* close the status file                          */
     call stream statusFile, "c", "CLOSE"

     call LineOut, "Rebooting your workstation please wait ..."

                    /* and reboot the workstation using SETBOOT       */
     "SETBOOT /IBD:C"

    end /* else */
  end  /* if stream( statusFile, "c", "QUERY EXISTS" ) = "" then */
  else
  do
                    /* second boot                                    */

                    /* normally nothing to do because the             */
                    /* configuration should now be okay               */
  end /* else */

                    /* delete the status file also on user breaks     */
UserBreak:

                    /* delete the status file if it exists            */
  if stream( statusFile, "c", "QUERY EXISTS" ) <> "" then
    "@del " statusFile "2>NUL 1>NUL"


  

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