Learn RPG4 with Real Code Examples

RPG IV modernizes the traditional RPG language with free-form syntax and modular design.

Integrated seamlessly with Db2 for i, enabling native database operations without SQL.

Supports ILE concepts like modules, procedures, service programs, and binding directories.

Used for building enterprise business logic, batch jobs, and transactional systems.

Forms the backbone of many legacy and modern IBM i applications in finance, logistics, and manufacturing.

Procedures and modules

Record-level I/O

Embedded SQL support

Data structures and subfields

Integrated file declarations (F-specs)

Free-form vs fixed-form RPG syntax

Files and F-specs

Data structures and subfields

Procedures and prototypes

ILE modular architecture

Source physical files (QRPGLESRC)

RPGLE modules

Service programs

Binding directories

Db2 tables/files

Define file access

Declare data structures

Write procedures

Compile program/module

Test via CL or calling program

Beginner: Simple CRUD program

Intermediate: Batch job with SQL + file I/O

Advanced: Service program with multiple modules

Expert: Full ERP subsystem

Architect: Event-driven API services with ILE architecture

RPG IV vs COBOL: RPG is more concise and database-integrated

RPG IV vs CL: CL is for scripting; RPG handles business logic

RPG IV vs Java on IBM i: Java is portable but slower for record I/O

RPG IV vs Node.js APIs: RPG is backend logic; Node.js is better for front-end integration

RPG IV vs Python on IBM i: Python is flexible; RPG excels in enterprise data consistency

RPG/400 - Traditional fixed-format

RPG IV (1994) - Modern ILE RPG introduced

Free-form enhancements (2000s)

Fully free-form declarations (2013+)

Continuous IBM enhancements via Technology Refreshes

ILE - Integrated Language Environment

F-spec - File definition specifications

Service Program - Shared library of procedures

Activation Group - Runtime isolation level

Db2 for i - Native IBM i database