Properly Passing Commands With Your Batch and MaxL Scripts

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I know that this may be a bit of a beginner topic for some of you, but I feel this is an essential part of creating the brotherly bond between your batch scripts and your MaxL scripts.  This post will also contain some of my best practices around this topic which will make your life much easier down the road.

Passing commands from one batch script to another is relatively simple, as long as you adhere to a standard when doing so.  For this example, we will pass the following information from one batch to another.

• Server Name
• Application Name
• Database Name
• Username
• Password

First we will create a "parent" batch script.  This script will use the call function to start up another "child" batch script within the same cmd window.  Below is an example of the "parent" script we will use.

Example 1 (Parent Batch Script):

REM *******************************************************
REM Script Name:   parent.bat
REM Purpose:       Example of how to pass commands
REM Process:       High level process list
REM *******************************************************

@ECHO ON

REM ****************** Call Child Batch *******************
CALL child.bat server1 application1 database1 scott password

This example above should be pretty self explanatory   The first thing we are doing is turning on the ECHO command to enable screen output and then we are calling the child.bat to execute.  You will notice in this example how we pass the connection information to the child.  

It is very important to note that the space represents a divider among multiple commands.  So if you are passing a value to the child script that has a space in it, you must put it in double quotes.  See the example line below where I have changed my password to one with a space in it. 

CALL child.bat server1 application1 database1 scott "pass word"

It also does not hurt to put the double quotes around commands that do not have a space either.  (see below)

CALL child.bat "server1" "application1" "database1" "scott" "pass word"

Now that we have successfully setup our Parent batch to pass commands to our child batch, we can now work on ensuring that the child batch script can accept these commands.  Below is an example of the child batch script and how to best manage these passed commands.

Example 2 (Child Batch Script):

REM *******************************************************
REM Script Name:      child.bat
REM Purpose:          Example of how to receive commands
REM                     and pass them to a MaxL Script
REM Process:          High level process list
REM Passed Commands:  1) Server Name
REM                   2) Application Name
REM                   3) Database Name
REM                   4) UserName
REM                   5) Password
REM *******************************************************

REM ****************** Set Variables **********************
SET ssd_server_name=$1
SET ssd_app_name=$2
SET ssd_db_name=$3
SET ssd_user_name=$4
SET ssd_password=$5
REM ****************** End Variables **********************

@ECHO ON

REM ****************** Call Child Maxl Script *************
CALL essmsh child_maxl.mxl %ssd_server_name% %ssd_app_name% %ssd_db_name% "%ssd_user_name%" "%ssd_password%"

You will notice a few things in this example. First, the way that the child batch script accepts the passed commands is with a dollar sign followed by a number.  This number represents the numeric position of the passed command.  Second, you will notice that I have assigned all of these passed commands to local variables.  This will help determine what the batch is expecting to receive from the parent batch script and also make referencing these command values much more user friendly.  Lastly, I have put quotes around some variables in the MaxL script call that could potentially have spaces in them.

MaxL scripts are a bit different in how they handle and accept these commands.  Below, I have posted the script of my test MaxL (child_maxl.mxl) that we called above.

Example 3 (Child MaxL Script):

/*******************************************************
Script Name:      child_maxl.mxl
Purpose:          Example of how to receive commands
                   in a MaxL script
Process:          High level process list
Passed Commands:  1) Server Name
                  2) Application Name
                  3) Database Name
                  4) UserName
                  5) Password
*******************************************************/

/****************** Set Variables **********************/
SET ssd_server_name=$1;
SET ssd_app_name=$2;
SET ssd_db_name=$3;
SET ssd_user_name=$4;
SET ssd_password=$5;
SET mxl_logfile_path="C:\Logs\child_maxl.log"
/****************** End Variables **********************/

spool on to $mxl_logfile_path;

login $ssd_user_name $ssd_password on $ssd_server_name;

logout;
spool off;
exit;

You can see that the MaxL script is similar to the batch syntax with some slight variations.  In this case, I passed 5 commands to the MaxL script, but only used 3 of them.

That's about it for a high level overview of how to pass commands from batch scripts to MaxL scripts.

As always, post your questions or comments in the comment section below and I will respond.