Mastering AS/400 Commands: Your Ultimate Guide to Over 25 Essential Control Language (CL) Commands

Mastering AS/400 Commands: Your Ultimate Guide to Over 25 Essential Control Language (CL) Commands 

Introduction: The Power of AS/400 Control Language

The AS/400, now known as IBM i, remains one of the most robust and reliable enterprise systems in the world. At its heart lies the Control Language (CL) – a powerful command set that serves as the

primary interface between users and the system. With over a thousand commands available, the AS/400 CL offers unparalleled control over system operations, programming tasks, and database management.

Whether you're a seasoned system administrator or a newcomer to the platform, understanding these commands is essential for efficient system

management. This comprehensive guide explores 25+ essential AS/400 commands that every professional should master.

Understanding AS/400 Command Structure

Before diving into specific commands, it's crucial to understand the naming convention. AS/400 CL commands follow a consistent Verb-Object structure with an optional adjective:

· Verb = Action to perform (e.g., WRK = Work with, DSP = Display)

· Adjective = Modifier (e.g., ACT = Active, COM = COM

· Object = What you're working with (e.g., JB = Jb, F = File)

For example, WRKACTJB breaks down as:

· WRK = Work with

· ACT = Active

· JB = Jb

This consistent syntax makes it easier to learn new commands once you understand the pattern.

Essential AS/400 Commands for Daily Operations

1. Object Creation Commands

CRTLIB (Create Library)

One of the most fundamental commands, CRTLIB creates a new library to organize objects. At minimum, you must specify the library name:

```

CRTLIB LIB(MYLIB)

```

CRTPF (Create Physical File)

This command creates a physical file to store data:

```

CRTPF FILE(MYLIB/CUSTOMER) RCDLEN(100)

```

CRTSRCPF (Create Source Physical File)

Essential for storing source code:

```

CRTSRCPF FILE(MYLIB/SOURCE) RCDLEN(92)

```

CRTPRTF (Create Printer File)

Defines printer file attributes:

```

CRTPRTF FILE(MYLIB/INVOICE) DEV(PRT01)

```

2. System and Object Management Commands

WRKACTJB (Work with Active Jbs)

Displays all active jobs on the system, allowing you to monitor and manage them:

```

WRKACTJB

```

DSPJB (Display Jb)

Shows detailed information about a specific jb:

```

DSPJB JB(123456/USER/JBNAME)

```

WRKSPLF (Work with Spooled Files)

Manages printer output and reports:

```

WRKSPLF

```

CHGSYSVAL (Change System Value)

Modifies system values for configuration:

```

CHGSYSVAL SYSVAL(QQRYTIMLMT) VALUE(3600)

```

3. File and Data Management Commands

DSPF (Display File)

View the contents of a database file:

```

DSPF FILE(MYLIB/CUSTOMER)

```

OVRDBF (Override with Database File)

Temporarily redirects file references:

```

OVRDBF FILE(INFILE) TOFILE(MYLIB/TESTFILE)

```

CPYF (Copy File)

Copies data from one file to another:

```

CPYF FROMFILE(MYLIB/MASTER) TOFILE(MYLIB/BACKUP)

```

RMVM (Remove Member)

Deletes a member from a physical file:

```

RMVM FILE(MYLIB/CUSTOMER) MBR(JAN2024)

```

4. Program and Development Commands

CRTBNDRPG (Create Bound RPG Program)

Creates a bound RPG program:

```

CRTBNDRPG PGM(MYLIB/INVOICE) SRCFILE(MYLIB/SOURCE)

```

CALL (Call Program)

Executes a program:

```

CALL PGM(MYLIB/INVOICE) PARM('CUST001')

```

STRDBG (Start Debug)

Initiates debugging mode:

```

STRDBG PGM(MYLIB/INVOICE)

```

CRTCMD (Create Command)

Creates user-defined commands:

```

CRTCMD CMD(MYLIB/MYCMD) PGM(MYPGM) SRCMBR(MYCMD)

```

5. System Configuration Commands

VRYCFG (Vary Configuration)

Activates or deactivates devices, lines, or controllers:

```

VRYCFG CFGOBJ(PRT01) CFGTYPE(*DEV) STATUS(*ON)

```

WRKCFGSTS (Work with Configuration Status)

Monitors configuration status:

```

WRKCFGSTS

```

CHGDEVD (Change Device Description)

Modifies device settings:

```

CHGDEVD DEVD(PRT01) MSGQ(QSYSOPR)

```

6. Message and Communication Commands

WRKMSGQ (Work with Message Queue)

Manages message queues:

```

WRKMSGQ MSGQ(QSYSOPR)

```

SNDMSG (Send Message)

Sends a message to a user or message queue:

```

SNDMSG MSG('System maintenance scheduled') TOUSR(ADMIN)

```

RCVMSG (Receive Message)

Retrieves messages from a queue:

```

RCVMSG MSGQ(QSYSOPR) RMV(*NO)

```

7. Library and Object Management Commands

DSPLIB (Display Library)

Views contents of a library:

```

DSPLIB LIB(MYLIB)

```

EDTLIBL (Edit Library List)

Modifies the library search list:

```

EDTLIBL

```

DLTOBJ (Delete Object)

Removes objects from the system:

```

DLTOBJ BJ(MYLIB/TEST) OBJTYPE(*PGM)

```

MOVOBJ (Move Object)

Transfers objects between libraries:

```

MOVOBJ OBJ(MYLIB/TEST) OBJTYPE(*FILE) TOLIB(TESTLIB)

```

8. System Control Commands

PWRDWNSYS (Power Down System)

Performs a controlled system shutdown:

```

PWRDWNSYS OPTION(*IMMED) RESTART(*NO)

```

ENDSBS (End Subsystem)

Stops a specific subsystem:

```

ENDSBS SBS(QINTER) OPTION(*IMMED)

```

STRPFRMON (Start Performance Monitor)

Initiates performance monitoring:

```

STRPFRMON

```

Advanced Command Features

Command Prompting

You can use F4 to prompt for command parameters when you need help remembering specific options. Simply type the command and press F4 to get interactive prompting with field-level help.

Generic Command Entry

Using an asterisk () allows you to find related commands. For example, entering WRK and pressing Enter displays all "Work with" commands available on the system.

Function Keys

Master these essential function keys for efficient command entry:

· F1 = Help

· F4 = Command prompting

· F9 = Retrieve previous command

· F12 = Cancel/Go back

Practical Examples

Creating a Simple CL Program

Here's a basic CL program that creates a library and copies a file:

```cl

PGM

    CRTLIB LIB(TESTLIB)

    CPYF FROMFILE(PRODLIB/MASTER) TOFILE(TESTLIB/BACKUP)

ENDPGM

```

Monitoring System Status

To check system activity at a glance:

```

WRKACTJB

DSPMSG

WRKSPLF

```

Automating Regular Tasks

Combine commands to create automated processes:

```cl

PGM

    DLYJB RSMTIME(*CURRENT + 1)

    SNDMSG MSG('Backup starting') TOUSR(SYSADMIN)

    SAVLIB LIB(PRODLIB) DEV(TAP01)

    SNDMSG MSG('Backup completed') TOUSR(SYSADMIN)

ENDPGM

```

Best Practices for AS/400 Command Usage

1. Use Library Lists

Maintain proper library lists using EDTLIBL to ensure commands can find required objects.

2. Implement Security

Use proper object authorities and consider creating user-specific command sets.

3. Document Your Commands

Create system documentation using DSPOBJD to track object details.

4. Error Handling

Monitor for error messages and use RCVMSG to handle exceptions gracefully.

5. Performance Considerations

Use WRKACTJB regularly to monitor system resources and identify potential bottlenecks.

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Conclusion

Mastering AS/400 commands opens up the full potential of this powerful system. From basic file operations to complex system management, these 25+ commands provide the foundation for efficient system administration and programming. The consistent verb-object syntax makes learning new commands intuitive, while powerful features like command prompting and generic entry help users of all skill levels.

Whether you're creating libraries with CRTLIB, managing jobs with WRKACTJB, or debugging programs with STRDBG, the AS/400 command set offers the flexibility and power needed for modern enterprise computing. As you become more familiar with these essential commands, you'll discover why the AS/400 platform continues to be a cornerstone of business computing worldwide.

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