ICS124 Session 11 Introduction to AS/400 1

By the end of this section, the student will be able to: Define the major difference between the AS/400 and UNIX regarding what is stored Define what an object is Use the AS/400 to create an object Describe the structure of AS/400 storage List the four library types in the library list Use the AS/400 to list the contents of the library list Describe the function of the two subsystems in the AS/400 Interact with the two subsystems List the four screen types of the AS/400 Recognize and use each of the screen types List the two types of help on the system, and describe the circumstances that result in each type of help being displayed Use the help system to answer questions in the Lab Describe the construction of commands in the AS/400 Use commands to perform some basic operations 2

AS/400 Introduction AS/400 (Application Server / 400) is a multiuser, multiprogramming system. The operating system of the AS/400 is called OS/400. It is based on a different approach to how computers can work. UNIX / Windows On UNIX and Windows operating systems everything is a file. Files are organized in hierarchies of directories. In the Windows environment, files have extensions that provide meaning to a file. For example, what do the following extensions relate to?.doc.xls.txt.dll.exe 3

AS/400, continued AS/400 On AS/400 everything is an object. Windows has file extensions, AS/400 has object types: WindowsAS/400 files-objects extensions-object types 4

Objects What is an object? object \ ’ äb-jikt\ n 1 : something that may be seen or felt; also : something that may be perceived or examined mentally. (The New Merriam-Webster Dictionary, Copyright 1989 by Merriam-Webster Inc.) An example of an object is a ball.  It has size, weight, colour, shape  It may be made of rubber, plastic, wood, glass...  It may be my ball, or it may be your ball. It has attributes- data 5

Objects, continued You can interact with a ball, for example: throw the ball bounce the ball catch the ball It has operations that can be performed- methods Objects as defined by computers In computers, objects have Data and Methods. I could define a ball to a computer by starting with a basic model called a ball, and then define attributes about the ball: ball.colour = yellow ball.shape = round ball.weight = 200g ball.madeOf = rubber I could then apply methods to the ball: ball.bounce 6

Objects, continued Objects as defined by computers, continued The concept of objects in a computer allow you to define as many different objects as you want. All with different Data (attributes), and manipulate them through their Methods independently. 7

AS/400 Structure If a Windows system stores files in directories, where does AS/400 store objects? Libraries Whereas Windows also stores directories inside of other directories, AS/400 does NOT store libraries inside of other libraries: 8

AS/400 Types of Objects Object types that exist in the AS/400 include: *LIB(remember these cannot be stored in libraries) *OUTQ *FILE *CMD *DOC *DTAQ *AUTL.... 9

AS/400 Library Lists In Windows and UNIX when you wish to execute a program, the computer searches the PATH to find your program. In AS/400 when you wish to find an object, the computer searches the Library List. The library list is stored in a system value called *LIBL The order that the computer searches the Library List is: SYS-system PRD-product CUR-current USR-user 10

AS/400 System Library List The system library list contains up to 15 libraries. This list is maintained in the system value QSYSLIBL. It will contain: QSYS - essential system objects such as programs and commands QSYS2 - additional system programs QHLPSYS - Help information QUSRSYS - contains other IBM-supplied objects for various system functions Product Library The system inserts a product library when the library is needed for some task a user has requested. For example, if a user requests a C program to be compiled, the compiler will be inserted as necessary. Current Library The current library is a specially designated user library where new objects are created by default. It will be searched before the user library. 11

AS/400 User Library List The user library list contains up to 25 libraries. This list is maintained in the system value QUSRLIBL. It will normally include at least: QTEMP QGPL 12

AS/400, continued Library Lists, continued In UNIX there are Absolute Paths and Relative Paths. In AS/400 there is the Library List and a version of the absolute path is the Qualified Name. The qualified name overrides the library list search order, and references a specific object in a specific library. The format of a qualified name is: library/object 13

AS/400, continued Managing *LIBL The user portion of the library list can be managed (CUR and USR library types) The commands to manage your library list are: DSPLIBL - display library list CHGCURLIB - change the current (default) library ADDLIBLE - add a library list entry (to user library list) EDTLIBL - add/change/delete/re-order library list (more on commands later) 14

AS/400, continued Subsystems of the AS/400 The AS/400 has two subsystems: QINTER - interactive QBATCH - batch QINTER handles the interactive session between the user and the computer. If necessary, it will submit batch jobs QBATCH requires no interaction with a user. It runs until completion. For example, compiling a program requires no interaction with a user. QINTER may be used to tell the computer to compile a program, QBATCH will be given the responsibility of performing the compile. Other batch jobs include the management of the print spool. 15

AS/400, continued AS/400 User Interface Windows is a GUI interface. The user interacts with the computer using a mouse to point to icons and perform actions by manipulating those icons. UNIX is a command line interface. The user interacts with the computer by typing commands. AS/400 is both command line and menu driven. The operations that are performed on the command line can also be performed through the menus. For example, the command DSPSYSVAL QAUTOCFG is the same as selecting option 7 from the main menu, then option 8, then scrolling through the list until you find QAUTOCFG, placing a 5 beside and pressing enter. Because of the menu system, there are four types of screens: Menu Data entry Informational Work-with list 16

AS/400, continued AS/400 User Interface, continued This is an example of a Menu screen: 17

AS/400, continued AS/400 User Interface, continued This is an example of a Data Entry screen: 18

AS/400, continued AS/400 User Interface, continued This is an example of a Informational screen: 19

AS/400, continued AS/400 User Interface, continued This is an example of a Work-with screen: 20

AS/400, continued AS/400 Help System There are two types of help available on the AS/400: Context-sensitive Help Extended Help Context-sensitive help Context sensitive help is available by pressing F1 while the cursor is positioned in a field, or in a column of values. Extended help Extended help is available from within Context-sensitive help by pressing F2, or by pressing F1 while the cursor is not in an entry field or a column of values. 21

AS/400, continued AS/400 Command Line The commands of the AS/400 are similar to UNIX in that there is a command followed by one or more parameters. AS/400 expects the parameters to be in a very specific order, unless there is a keyword to identify the parameter. For example: DSPSYSVAL QAUTOCFG is DSPSYSVAL SYSVAL(QAUTOCFG) or CPYF myfile yourfile is CPYF FROMFILE(myfile) TOFILE(yourfile) or CPYF TOFILE(yourfile) FROMFILE(myfile) 22

AS/400, continued AS/400 Command Line, continued The format of the commands follow a predictable pattern: VERB-NOUN Verbs: CALL- execute a programRST- reset CLR- clearRTV- retrieve CPY- copySAV- save CRT- createSBM- submit DLT- deleteSND- send DSP- displaySTR- start EDT- editWRK- work GRT- grant INZ- initialize OPN- open RCL- reclaim RCV- receive RLS- release RMV- remove 23

AS/400, continued AS/400 Command Line, continued VERB-NOUN Nouns: D- description E- entry F- file L- list Q- queue DFU- data file utility RPG- Report Program Generator SDA- Screen Design Aid utility SEU- Source Entry Utility LIB- library OUTQ- output queue (this is a combination of two nouns) MSGQ- message queue JOBQ- job queue... 24