Library & Object Concepts:

Overview:

This module enables the student to understand the concept of Library & File object to store programming source.

Outline:

Topics covered,

· Library creation

Library list
Parts of Library List
Source Physical files.

Objective:

By the end of this module, the student should be able to:

Create a Library
Understand the concept of Library List.
Understand the part of Library List.
Commands related to Library.
Create the source Physical files.

Library:

Definition:

An AS/400 object used to group objects within it.

Usage:

Library object helps to group various AS/400 objects. Any object is created with reference to a Library object. Library helps to run AS/400 commands like SAVOBJ, RSTOBJ to run on group of objects referred to a library. Assigning rights at Library object can manage user authorization to objects.

Types/Values:

PROD - This library is containing programs and related data needed for license program that are installed on your system. The product library part is changed by the system as users runs commands or menus to include the library where the library code is used.

TEST - This is a test library. All objects in a test library can be updated during testing, even if special protection is requested for production libraries.

System supplied libraries:

QSYS - This library is containing objects such as user profiles that are used by the system. This part is defined by the system values QSYSLIBL and is usually the same for all jobs. For a specific job however a library can be added or removed from the system part by entering the change system library list (CHGSYSLIBL) commands from within the job. The list can contain as many as 15 names.

QGPL - It is General Purpose Library. It is similar to root directory in PC. By default the system will create the file in QGPL.

QTEMP - It is system library. Every job has its own QTEMP library. The library gets cleared and deleted when a new job starts. QTEMP library cannot be renamed or deleted.

Notes:

Library objects cannot be nested.

Library List:

Definition:

Library list stores the names of libraries, which will be searched by system for a object.

Usage:

Search Object:

It defines the order of libraries that the operating system uses to find objects. (similar to the "path" on PC's.)

When you execute a command or call a program, the AS/400 must know where to find the command or program. Sometimes, you specify the library explicitly. But if you don't, the AS/400 will find your command or program by looking in each library in your library list. It will use the first one that it finds.

Testing:

This is very handy for testing. If you are testing a version of a program, you can put it in a test library, which is at the top of your library list. Then, whenever you specify a program or refer to a file, the system will use any object it can find in the test library. If it can't find it there, it will look further through your library list until it finds it.

So, setting up a test environment is as simple as:

1) Create a test library.

2) Put objects that you want to test in the library. These can be files, menus, programs or any AS/400 object.

3) Insert the test library name in your library list before your production libraries.

Now you can execute test programs and modify test data. The best part is that you don't need to copy production programs or files into the test library unless they will be affected by the test. That is, all those supporting database files that you need to run a program, but that are used for input only, do not need to be copied to the test library. Of course, if you are unsure if a file will be modified during your test procedure, copy it to the test library anyway.

Once you have inserted the test library name in your library list, you will want to make sure everything is in the proper order. Use the DSPLIBL command to see your library list. You will probably see three types of list entries:

1) The SYS libraries have operating system objects. This is where the AS/400 commands and menus live.

2) The CUR library is your current library. This is your first user library and is where objects are created if you don't specify which library to use.

3) The USR libraries list your other user libraries.

Use EDTLIBL to change your user libraries. You can rearrange the list, remove libraries or add libraries. Notice that you can't see the SYS or CUR libraries when you use EDTLIBL. The only way to change the current library is with the CHGCURLIB command.

Command related to library:

Command	Description	Usage
CRTLIB	Create Library	Create new library object
DLTLIB	Delete library	Delete a library object
CLRLIB	Clear library	Delete all objects in a library
DSPLIB	Display Library	Displays contain of a library
EDTLIBL	Edit library list	Define list of libraries for object search. (Only user libraries can be defined by user)
DSPLIBL	Display library list	Show list and sequence of libraries used for object search. This includes system libraries and current library
ADDLIBLE	Add library list entry	Add one library-to-library list. User can define in which position in search sequence the library should be added.
RMVLIBLE	Remove library list entry	Specifies the name of the library that is remove from the user portion of the library list.
CHGLIBL	Change library list	Changes the user portion of the current job’s library list with the list of libraries specified by the user. This command does not affect the system of the library list, nor does it affect any other job’s library list.

Lab Tasks:

1. Create 3 libraries as following

a. PB01U01S - Program source library for student PB01U01

b. PB01U01O - Program/Screen/Printer Object library for student PB01U01

c. PB01U01D - Data object library for student PB01U01

2. Define the above libraries in library list

3. Display library list

4. Add one library to library list using command ADDLIBLE

Follow steps to complete the tasks:

1. Create Library

a. At command line type CRTLIB

b. Press F4

c. Type Library name (e.g. PB01U01O)

d. Type Text description (e.g. ‘Program Source Library for user PB01U01’ or User name). Its in single cote only.

e. Press Enter

f. Repeat steps for creating libraries PB01U01D.

MAIN OS/400 Main Menu

System: S653278B

Select one of the following:

1. User tasks

2. Office tasks

4. Files, libraries, and folders

6. Communications

8. Problem handling

9. Display a menu

10. Information Assistant options

11. Client Access/400 tasks

90. Sign off

Selection or command

===> CRTLIB

F3=Exit F4=Prompt F9=Retrieve F12=Cancel F13=Information Assistant

F23=Set initial menu

Create Library (CRTLIB)

Type choices, press Enter.

Library . . . . . . . . . . . . PB01U01O Name

Library type . . . . . . . . . . *PROD *PROD, *TEST

ASP number . . . . . . . . . . . 1 1-32, *ASPDEV

ASP device . . . . . . . . . . . *ASP Name, *ASP, *ASPGRPPRI...

Text 'description' . . . . . . . 'Program Source Library for User PB01U01’

F3=Exit F4=Prompt F9=Retrieve F12=Cancel F13=Information Assistant

PRESS ENTER TO CREATE THIS LIBRARY. USING ABOVE COMMAND CREATE ANOTHET LIBRARY ‘PB01U01D’

Define library list

a. Type command EDTLIBL at command line

b. Press F4 or Enter

c. Type names of your libraries as per the screen below

d. Press Enter

Above process gives you following screen- WHERE you are able to add your screen in Library list.

Edit Library List

System: S653278B

Type new/changed information, press Enter.

Sequence Sequence Sequence

Number Library Number Library Number Library

0 150 300

10 QGPL 160 310

20 QTEMP 170 320

30 PB01U01S 180 330

40 PB01U01D 190 340

50 200 350

60 210 360

70 220 370

80 230 380

90 240 390

100 250 400

110 260 410

120 270 420

130 280 430

140 290 440

More...

F3=Exit F5=Refresh F12=Cancel

2. Display library list

a. Type command DSPLIBL and press Enter

Display Library List

System: S653278B

Type options, press Enter.

5=Display objects in library

ASP

Opt Library Type Device Text

QSYS SYS System Library

QSYS2 SYS System Library for CPI's

QHLPSYS SYS

QUSRSYS SYS System Library for Users

QPDA PRD

SHEET CUR

QGPL USR General Purpose Library

QTEMP USR

SHEET USR

Bottom

F3=Exit F12=Cancel F17=Top F18=Bottom

Notes: Observe QSYS, QGPL and QTEMP included in library list by default. You can remove or change position for QTEMP, QGPL.

3. Add one library to library list using command ADDLIBLE

a. At command line type ADDLIBLE

b. Press F4

c. Type library name PB01U01D

d. Enter position *LAST

e. Press Enter

Add Library List Entry (ADDLIBLE)

Type choices, press Enter.

Library . . . . . . . . . . . . Name

Library list position:

List position . . . . . . . . *FIRST *FIRST, *LAST, *AFTER...

Reference library . . . . . . Name

Bottom

F3=Exit F4=Prompt F5=Refresh F12=Cancel F13=How to use this display

F24=More keys

To add libraries in library list add name of libraries which makes add your library in library list.

Source physical File:

In AS/400 source for RPG/CL/COBOL programs, PF/LF structures are stored in a object having type File. This file will have attribute as “PF-SRC”. The object is called as Source Physical File.

When AS/400 is shipped from the factory it has few Source Physical File in library QGPL (General Purpose Library). The few of these Source files are, QDDSSRC, QRPGSRC, QCLPSRC (this is not a complete list) in which the characters DDS, RPG, CLP denotes Data Definition Source, RPG program Source, CL program source respectively.

Programmer can use the factory shipped Source Physical files for storing the program, PF/LF sources. But this is not a recommended method. Sources should be stored in different Files as per the Project. This gives better manageability of the source.

LAB Session:

1. Create source physical file MYCLP in library PB01U01S for storing “CL program Source”

2. Create source physical file MYRPG in library PB01U01S for storing “RPG program Source”

3. Create source physical file MYDDS in library PB01U01D for storing “PF/LF program Source”

4. Create source physical file MYSCR in library PB01U01O for storing “Display screen program Source”

5. Create source physical file MYPRT in library PB01U01O for storing “Printer file program Source”

6. Create source physical file MYRPGLE in library PB01U01S for storing “RPG ILE program Source”

Steps:

1. Type command “CRTSRCPF” at command line and press Enter

MAIN OS/400 Main Menu

System: S653278B

Select one of the following:

1. User tasks

2. Office tasks

3. General system tasks

4. Files, libraries, and folders

5. Programming

6. Communications

7. Define or change the system

8. Problem handling

9. Display a menu

10. Information Assistant options

11. Client Access/400 tasks

90. Sign off

Selection or command

===> CRTSRCPF

F3=Exit F4=Prompt F9=Retrieve F12=Cancel F13=Information Assistant

F23=Set initial menu

2. Type File Name, library Name and File description as shown and press Enter

Create Source Physical File (CRTSRCPF)

Type choices, press Enter.

File . . . . . . . . . . . . . . Name

Library . . . . . . . . . . . PB01U01D Name, *CURLIB

Record length . . . . . . . . . 92 Number

Member, if desired . . . . . . . *NONE Name, *NONE, *FILE

Text 'description' . . . . . . . *BLANK

Bottom

F3=Exit F4=Prompt F5=Refresh F10=Additional parameters F12=Cancel

F13=How to use this display F24=More keys

NOTE : The record length is 92. The source sequence number contains 6 bytes, the date contains 6 bytes, and the source statement contains 80 bytes.

MAIN OS/400 Main Menu

System: S653278B

Select one of the following:

1. User tasks

2. Office tasks

3. General system tasks

4. Files, libraries, and folders

5. Programming

6. Communications

7. Define or change the system

8. Problem handling

9. Display a menu

10. Information Assistant options

11. Client Access/400 tasks

90. Sign off

Selection or command

===>

F3=Exit F4=Prompt F9=Retrieve F12=Cancel F13=Information Assistant

F23=Set initial menu

File MYDDS created in library PB01U01D.

Msg Received after creation Of SRCPF

You will receive the message as displayed above after creating of a MYDDS source physical file.

1. Repeat the steps for other libraries.

After successful creation of your libraries and source physical file you have to work with following command to work with members.

MAIN OS/400 Main Menu

System: S653278B

Select one of the following:

1. User tasks

2. Office tasks

3. General system tasks

4. Files, libraries, and folders

5. Programming

6. Communications

7. Define or change the system

8. Problem handling

9. Display a menu

10. Information Assistant options

11. Client Access/400 tasks

90. Sign off

Selection or command

===> strpdm

F3=Exit F4=Prompt F9=Retrieve F12=Cancel F13=Information Assistant

F23=Set initial menu

STRPDM : START PROGRAM DATA MANAGER, which displays following screen.

AS/400 Programming Development Manager (PDM)

Select one of the following:

1. Work with libraries

2. Work with objects

3. Work with members

9. Work with user-defined options

USE THIS OPTION TO WORK WITH MEMBERS

Selection or command

===> 3

F3=Exit F4=Prompt F9=Retrieve F10=Command entry

F12=Cancel F18=Change defaults

Press ENTER

Specify Members to Work With

Type choices, press Enter.

File . . . . . . . . . . MYDDS Name, F4 for list

Library . . . . . . . . PB01U01D *LIBL, *CURLIB, name

Member:

Name . . . . . . . . . *ALL *ALL, name, *generic*

Type . . . . . . . . . *ALL *ALL, type, *generic*, *BLANK

F3=Exit F4=Prompt F5=Refresh F12=Cancel

Press enter which gives you following screen

Work with Members Using PDM S653278B

File . . . . . . MYDDS

Library . . . . PB01U01D Position to . . . . .

Type options, press Enter.

2=Edit 3=Copy 4=Delete 5=Display 6=Print 7=Rename

8=Display description 9=Save 13=Change text 14=Compile 15=Create module...

Opt Member Type Text

(No members in file)

Parameters or command

===>

F3=Exit F4=Prompt F5=Refresh F6=Create

F9=Retrieve F10=Command entry F23=More options F24=More keys

Now you have to start creation of member. Its in next session. Press ‘F3’ to exit.

Questions on above session:

· Using the command CRTLIB, create a Library TEST suffixed by your user name.

· Check whether your library has been created using following commands:

WRKLIB or DSPLIB. Add the created library to the library list using commands ADDLIBLE or EDTLIBL

· Check your current library using DSPLIB and DSPLIBL.

· Display libraries of all the users using command DSPLIB with *ALL as the value for the parameter LIB.

· Using the command CHGCURLIB change your current library to library which you have created and check whether it has been changed by using the command DSPLIBL.

· Try WRKSPLF and WRKUSRJOB commands.

· Print all the libraries in your library list to a spooled file using the command DSPLIBL OUTPUT (*PRINT) and view the spool file.

· Display all the commands starting with ‘CRT’ by using the command SLTCMD CMD (CRT*).

· Using the command DLTLIB, delete the library, which you have created above.

AS/400 Forum

Tuesday, December 3, 2013

Day-2

Library & Object Concepts:

Definition:

Notes:

Definition:

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