Control Language Basic Part 1

Control Language:

Control language also knows as CL. CL is a language which is used in AS400 for controlling purpose. It is basically a well organized language as its basic is commands with different parameter.

Let’s study an example to study how CL works.

Steps to create a CL program:

1.    WRKMBRPDM

2.    Press F6

3.    Give the object name

4.    Type parameter should have value as CLP.

Press Enter

You will get a blank screen.

We will study a program which will display User Profile.

1-    PGM

2-    DCL        VAR(&USER) TYPE(*CHAR) LEN(10)

3-    DCL        VAR(&MSG) TYPE(*CHAR) LEN(40)

4-    RTVUSRPRF  RTNUSRPRF(&USER)

5-    CHGVAR     VAR(&MSG) VALUE(&USER)

6-    SNDPGMMSG  MSG(&MSG)

7-    ENDPGM

Let’s see what each line will do in this program’

1^st line show start of the program

2^nd and 3^rd line we declare two variable named User and Msg.

4^th line shows a command which is used to retrieve user profile.

5^th line moves value of user profile to msg variable.

6^th line sends the user name to program message which is basically appears upon the bottom.

7^th line shows how to end a CL program.

So If we try to understand basic structure of any CL Program:

ü  Start

ü  Declare variables

ü  Declare files

ü  Use calculation or assignment

ü  End program.

Just one more thing here, whenever we write any program its developer responsibility to add meaning full comments to programs. So in CL  /* */ are used to do comment.

/* This Program will send User Profile*/