CL/400 Interview Questions

CL400 Interview Questions

1. What are the disadvantages in CL? (Or) What is the difference between RPG and CL?   

a.       You can’t perform Insert, Update and Delete operation in CL.

b.      You can’t use printer files in CL.

c.       You can’t use sub files in CL except Message Subfile

d.      You can use only one file in CL.

2.  How do you read a specific record in a keyed database file in a CL program?

OVRDRF FILE (filename) POSITION (*KEYx a b c) and RCVF

3.  What CL command is used to read a file?

RCVF - Receive File

4. How can you read a file in CL?

Thro’ RCVF command we can read a file. To read all the records we should use MONMSG command with MSGID (CPF0864). So if the end of file reached then the message CPF0864 is sent to the program so the variable will not be changed by the RCVF command.

5. How can you read a file in CL?

Thro’ RCVF command we can read a file. To read all the records we should use RCVF followed by MONMSG command with MSGID (CPF0864) and followed by GOTO with command label to branch and prier to RCVF command. So if the end of file reached then the message CPF0864 is sent to the program so the variable will not be changed by the RCVF command otherwise.

6. How can you set lower limit to a file in CL?

            By two way we can set.

                                i.            POSDBF with parameter  “File Position” set to “*Start”.

                              ii.            OVERDBF which allows to position the file by Key Value, by RRN value, or set to *START

7.  What CL command is equivalent to write a display file in RPG?

SNDF - Send File

8.  What CL command is equivalent to write/read a display file in RPG?

SNDRCVF - Send/Receive File

9.  What CL command is used to determine the logical files associated with a particular physical file?

DSPDBR - Display Database Relations

10.  If the field is defined in DDS, how is it referenced in a CL program?

By declaring the field (DCL) and placing an ampersand in front of the variable name.

11. What are the data types available in CL?

            *CHAR, *DEC, *LGL

12.  What is the main use of MONMSG?

Error trapping.

13. What MONMSG in CL?

This command monitors the messages send to the program message queue for the conditions specified in the command. There are two levels of MONMSG commands.

Program level is specified immediately following the last declares command in your CL program. You can use as many as 100 program level MONMSG commands.

Command level immediately follows a CL command. You can use as many as 100 command level MONMSG commands for a single command.

If you monitor a message by giving message ID as CPF0000 then any error will come to MONMSG routine

14.  How can a programmer send a message from a CL program?

Using the SNDPGMMSG command - Send Program Message

15. What are the various messages in CL?

A message is a communication sends from one user or program to another. There are two types of messages available. One is Immediate messages, which are created by the program or system user when they are sent and not permanently stored in the system. Another type is Predefined messages, which is created before they are used. These messages are placed in a message file when they are created, and retrieved from the file when they are used. The CRTMSGF command is used to create a Predefined message. The ADDMSGD, DSPMSGD, RMVMSGD commands are used to add a message description, display message description and remove message description respectively. CHGMSGD or WRKMSGD is used to change the description.

Predefined message in CL                  SNDUSRMSG, SNDPGMMSG, RTVMSG

            Predefined message in display files    ERRMSGID, SFLMSGID, MSGCON and MSGID

            Immediate message in CL                  SNDUSRMSG, SNDPGMMSG, SNDMSG, SNDBRKMSG

            Immediate message in display files    ERRMSG, SFLMSG

16.  What is the purpose of the CHGVAR command?

To change the value associated with a CL variable

17.  How do you access the local data area in a CL program?

RTVDTAARA DTAARA (*LDA) RTNVAR (&var)

18.  What are the various steps involve accessing Data Area in CL?

First we get the data from the data area by using the command RTVDTAARA. If you want edit the data of the data area use CHGDTAARA command else if you want view the data of the data area use DSPDTAARA command

19.  What is a command label?

An area of transfer within a CL program from which to continue processing directed by a GOTO command.

20.  Explain parameter passing.

To pass variables from a CL or RPG program to another CL or RPG program.

21.  How can a programmer exit out of a CL program?

By using a RETURN command.

22. Why would the PGM line contain a PARM?

The CL program is using a value passed from another processing program.

23. How to create user-defined command?

First of all create a CL program with a command and compile it. After create a CMD type program. Then by using CRTCMD command define user-defined command.

E.g.    

CLP 01

PGM

DSPLIBL

ENDPGM

CMD01

CMD

CRTCMD

CLP name ----------------------   : CLP01

Library      ----------------------   : SKANDASAMS

CMD named -------------------  : CMD01

Library                  ----------------------   : SKANDASAMS

User-defined command ------  : A

Now if you type A and press enter key, system will display library list.

24. How to retrieve a Date in CL?

By using RTVSYSVAL command we ca retrieve a date in CL. The various date formats are *JOB, *SYSVAL, *MDY, *DMY, *YMD, *JUL etc. [if you want system time, you have to specify *time in the format]

25. What are the different date types?

v        *ISO – YYYY-MM-DD

v        *USA – MM/DD/YYYY

v        *EUR – DD.MM.YYYY

v        *JUL – YY/DDD

v        *JOB

v        *SYSVAL

v        *MDY

v        *DMY

v        *YMD

v        *JUL

*ISO is the default date type.

Format of system value is MM/DD/YY

26. How can you check the date in CL?

By the command CVTDAT.

27. What is the max length of variable in CL?

            11

28. What are the advantages of CL?

§  Because commands are compiled and stored in a form, they can be run immediately and it is faster than entering the commands in command line.

§  Some CL commands cannot be executed in command line, so we need CL program for them. Eg. RTVSYSVAL, RTVDTAARA

§  Cl program can be tested and debugged like other HLL program.

29. How to find the field description of an object?

            DSPFFD, DSPOBJD

Share This:

Facebook

Twitter

Google Plus

Pinterest

Linkedin