OpenRPG

OpenRPG is an open-source, clean-room compiler for IBM RPG IV free-format source code. The rpgc binary compiles .rpgle source into executables that run on macOS, Linux, or Windows — no IBM i required.

IBM i compatibility

90.1% — of the 473 test programs in this repository, rpgc does the same thing as IBM's ILE RPG compiler with 426: both compile the program, or both reject it.

What this rating means: it measures the RPG that OpenRPG implements, as exercised by the test programs in this repository. It is not a claim that OpenRPG supports that share of IBM i RPG. Features OpenRPG does not have yet have no test programs, so they are not in the count. The rating is recalculated each time the IBM i conformance workflow runs (last: 2026-10-27). Details: IBM i Conformance Results.

Installation

Pre-built packages are available on the Releases page.

macOS

Download openrpg-<version>.pkg from the Releases page — it bundles both rpgc and dspfc. Two things must be present before installing. The Xcode Command Line Tools supply the clang++ that rpgc invokes to build the programs it compiles, plus the ncurses headers display-file programs need:

xcode-select --install     # skip if `xcode-select -p` already prints a path

And the unixodbc library, which rpgc itself links against:

brew install unixodbc

Installing Homebrew pulls in the Command Line Tools, so if you already have brew you almost certainly have them.

Apple Silicon (arm64) only — GitHub's hosted macOS runners dropped Intel support, so there's no x86_64 build.

If you plan to use SQL or RLA features, see Database Connectivity — macOS for the additional SQLite driver registration step.

Because OpenRPG is not code-signed with an Apple Developer certificate, macOS Gatekeeper will block the installer. Clear the quarantine flag before opening it:

xattr -cr ~/Downloads/openrpg-*.pkg

Then double-click the .pkg to install. This puts rpgc on your PATH system-wide.

Linux

Download the .deb (Debian/Ubuntu) or .rpm (RHEL/Fedora) from the Releases page — each is available for both x86_64 (amd64/x86_64) and ARM64 (arm64/aarch64, e.g. AWS Graviton, Raspberry Pi). The packages declare everything they need — the C++ compiler, the unixODBC headers and library, and the ncurses headers for display-file programs — so the package manager will pull it all in automatically.

Debian/Ubuntu:

sudo dpkg -i rpgc_*.deb
sudo apt-get install -f     # resolves any missing dependencies

RHEL/Fedora:

sudo dnf install ./rpgc-*.rpm

Windows

Download openrpg-<version>-windows-x64.exe (x86_64) or openrpg-<version>-windows-arm64.exe (Windows on ARM, e.g. Surface Pro X, Snapdragon X devices) from the Releases page and run the installer. It adds rpgc to your PATH automatically.

No other prerequisites needed. The installer bundles a self-contained C++ compiler (a trimmed llvm-mingw toolchain) that rpgc/dspfc use to build the programs they compile, plus a PDCurses build for WORKSTN/display-file programs — you don't need MSYS2, Visual Studio, or anything else installed first. (SQL/RLA features are the one exception: those still need a platform ODBC driver installed separately — see Database Connectivity below.)

ARM64 note: among the ODBC drivers this guide covers, only Microsoft's ODBC Driver 18 for SQL Server (18.2+) publishes a native ARM64 Windows build. SQLite, PostgreSQL, and MySQL/MariaDB don't — their installers are x86_64-only — so SQL/RLA features against those three aren't available on Windows ARM64 without building a driver from source yourself. See Database Connectivity below.

Quick Start

hello.rpgle:

**FREE
DCL-S msg VARCHAR(50);
msg = 'Hello from RPG!';
DSPLY msg;
*INLR = *ON;

rpgc hello.rpgle
./hello

Output:

Hello from RPG!

Usage

rpgc <source-file> [options]

Flag	Description
`-o file`	Output file
`-g`	Compile with debug symbols for source-level debugging
`-v`	Print version and exit

rpgc program.rpgle              # produces ./program
rpgc program.rpgle -o myapp     # produces ./myapp
rpgc -v                         # print version

SQL programs (.sqlrpgle) are linked with ODBC automatically — no extra flags needed.

Database Connectivity

SQL programs (.sqlrpgle) and RPG programs that use record-level access (RLA) connect to databases through ODBC. OpenRPG works with any database that has an ODBC driver — SQLite, PostgreSQL, MySQL, SQL Server, Db2, and more.

Platform Setup

The steps below use SQLite as the example. Other database drivers follow the same install-and-register pattern.

macOS

Install the unixODBC runtime and the SQLite ODBC driver:

brew install unixodbc sqliteodbc

Important — manual driver registration required. Homebrew installs the SQLite driver library but does not register it with unixODBC. Without this step Driver={SQLite3} silently fails — programs compile but produce no output from SQL or RLA operations.

Register the driver once after installation:

DRIVER=$(brew --prefix)/lib/libsqlite3odbc.dylib
printf '[SQLite3]\nDescription=SQLite3 ODBC Driver\nDriver=%s\nSetup=%s\n' \
  "$DRIVER" "$DRIVER" \
  | ODBCSYSINI=/opt/homebrew/etc odbcinst -i -d -f /dev/stdin

Also add ODBCSYSINI to your shell profile so unixODBC can find its configuration whenever you run a compiled program:

# add to ~/.zshrc or ~/.bash_profile
export ODBCSYSINI=/opt/homebrew/etc

Then reload your shell (source ~/.zshrc) or open a new terminal.

Linux — Ubuntu / Debian

sudo apt install unixodbc unixodbc-dev libsqliteodbc

libsqliteodbc registers the driver automatically. unixodbc-dev provides the ODBC headers that rpgc needs when it compiles generated C++ for SQL programs.

Linux — RHEL / Fedora

sudo dnf install unixODBC unixODBC-devel sqliteodbc

Windows

x86_64 only — the ch-werner installer has no ARM64 build. On Windows ARM64, SQLite via ODBC isn't available unless you compile the driver yourself.

Download and run the SQLite ODBC installer from www.ch-werner.de/sqliteodbc (sqliteodbc_w64.exe for 64-bit).

The installer registers the driver as SQLite3 ODBC Driver. To use the shorter Driver={SQLite3} form in connection strings (matching the examples in this guide), add a registry alias. Run the following in an elevated PowerShell prompt:

$key     = "HKLM:\SOFTWARE\ODBC\ODBCINST.INI"
$dllPath = (Get-ItemProperty "$key\SQLite3 ODBC Driver" -Name Driver).Driver
New-Item         "$key\SQLite3"         -Force | Out-Null
New-ItemProperty "$key\SQLite3" -Name Driver -Value $dllPath -PropertyType String -Force | Out-Null
New-ItemProperty "$key\SQLite3" -Name Setup  -Value $dllPath -PropertyType String -Force | Out-Null
Set-ItemProperty "$key\ODBC Drivers"    -Name SQLite3 -Value Installed

Alternatively, skip the alias and use the full name in your connection strings: Driver={SQLite3 ODBC Driver}.

Connecting from RPG Source

Option 1 — explicit EXEC SQL CONNECT in the source file:

DCL-S connStr VARCHAR(200);
connStr = 'Driver={SQLite3};Database=/path/to/myapp.db;';
EXEC SQL CONNECT USING :connStr;

Option 2 — rpgc.conf (no EXEC SQL CONNECT needed):

Create a config file with your DSN and rpgc wires up the connection automatically at startup, exactly like an IBM i job environment:

# ~/.rpgc.conf       — applies to all programs for your user
# ./rpgc.conf        — project-specific, takes priority over ~/.rpgc.conf
# /etc/rpgc.conf     — system-wide default

DB_DSN=Driver={SQLite3};Database=/path/to/myapp.db;

Option 3 — RPGC_DSN environment variable (highest priority, useful for CI):

RPGC_DSN="Driver={SQLite3};Database=./test.db;" rpgc myprog.sqlrpgle
./myprog

PostgreSQL Example

This complete example connects to PostgreSQL, runs an aggregate query, then iterates a cursor to print results. Save it as pg_employees.sqlrpgle.

Setup (one time):

# macOS — install and register the driver
brew install psqlodbc
DRIVER=$(brew --prefix)/lib/psqlodbcw.so
printf '[PostgreSQL Unicode]\nDescription=PostgreSQL ODBC Driver (Unicode)\nDriver=%s\nSetup=%s\n' \
  "$DRIVER" "$DRIVER" \
  | ODBCSYSINI=/opt/homebrew/etc odbcinst -i -d -f /dev/stdin

# Create a demo database and populate it
psql -U $USER postgres -c "CREATE DATABASE rpgdemo;"
psql -U $USER rpgdemo -c "
CREATE TABLE employees (
  id SERIAL PRIMARY KEY, name VARCHAR(50),
  dept VARCHAR(30), salary DECIMAL(9,2)
);
INSERT INTO employees (name, dept, salary) VALUES
  ('Alice Johnson', 'Engineering', 85000),
  ('Bob Martinez',  'Marketing',   62000),
  ('Carol Smith',   'Engineering', 91000),
  ('David Lee',     'HR',          58000);"

pg_employees.sqlrpgle:

**FREE

DCL-S connStr  VARCHAR(200);
DCL-S empName  VARCHAR(50);
DCL-S salary   PACKED(9:2);
DCL-S total    PACKED(11:2);
DCL-S rowCount INT(10);
DCL-S dspLine  VARCHAR(52);   // DSPLY shows at most 52 characters

connStr = 'Driver={PostgreSQL Unicode};Server=localhost;Port=5432;Database=rpgdemo;Uid=dlong;Pwd=;';
EXEC SQL CONNECT USING :connStr;

// Aggregate: headcount and total payroll for Engineering
EXEC SQL SELECT COUNT(*), SUM(salary)
         INTO   :rowCount, :total
         FROM   employees
         WHERE  dept = 'Engineering';

DSPLY ('Engineering headcount: ' + %CHAR(rowCount));
DSPLY ('Total payroll:         $' + %CHAR(total));
DSPLY '---';

// Cursor: list Engineering employees, highest salary first
EXEC SQL DECLARE c1 CURSOR FOR
  SELECT name, salary FROM employees
  WHERE  dept = 'Engineering'
  ORDER  BY salary DESC;

EXEC SQL OPEN c1;
DOW SQLCODE = 0;
  EXEC SQL FETCH c1 INTO :empName, :salary;
  IF SQLCODE = 0;
    dspLine = empName + '  $' + %CHAR(salary);
    DSPLY dspLine;
  ENDIF;
ENDDO;
EXEC SQL CLOSE c1;

EXEC SQL DISCONNECT;
*INLR = *ON;

Compile and run:

rpgc pg_employees.sqlrpgle -o pg_employees
./pg_employees

Output:

Engineering headcount: 2
Total payroll:         $176000.00
---
Carol Smith  $91000.00
Alice Johnson  $85000.00

The full source is in examples/pg_employees.sqlrpgle.

Supported Databases

Database	macOS	Linux (apt)	Windows	Example DSN
SQLite	`brew install sqliteodbc` + register (see above)	`apt install libsqliteodbc`	ch-werner.de/sqliteodbc	`Driver={SQLite3};Database=/path/to/file.db;`
PostgreSQL	`brew install psqlodbc`	`apt install odbc-postgresql`	psqlodbc.postgresql.org	`Driver={PostgreSQL Unicode};Server=localhost;Port=5432;Database=mydb;Uid=user;Pwd=pass;`
MySQL / MariaDB	`brew install mysql-connector-odbc`	`apt install odbc-mariadb`	dev.mysql.com/downloads/connector/odbc	`Driver={MySQL ODBC 8.0 Unicode Driver};Server=localhost;Database=mydb;User=user;Password=pass;`
SQL Server	—	Microsoft ODBC Driver	Microsoft ODBC Driver	`Driver={ODBC Driver 18 for SQL Server};Server=localhost;Database=mydb;Uid=user;Pwd=pass;`
IBM Db2	—	IBM Data Server Driver	IBM Data Server Driver	`Driver={IBM DB2 ODBC DRIVER};Database=mydb;Hostname=localhost;Port=50000;Protocol=TCPIP;Uid=user;Pwd=pass;`

For RHEL/Fedora, substitute the equivalent dnf package name (e.g. psqlodbc → postgresql-odbc).

Windows ARM64: of the drivers above, only SQL Server's Microsoft ODBC Driver (18.2+) ships a native ARM64 build. SQLite, PostgreSQL, and MySQL/MariaDB are x86_64-only on Windows.

Compiling SQL Programs Manually

If you generate .cpp files with rpgc -S and compile them yourself (e.g., in a Makefile), link with the platform ODBC library. The flags must appear after the source file:

Platform	Flags
macOS	`-I$(brew --prefix)/include -L$(brew --prefix)/lib -lodbc`
Linux	`-lodbc`
Windows (MinGW)	`-lodbc32`

On Windows, the compiler rpgc itself uses is bundled with the installer at <install-dir>\mingw\bin\<x86_64\|aarch64>-w64-mingw32-clang++.exe (that directory is also on PATH after installing, so clang++ resolves to it directly) — no separate MinGW/MSYS2 install needed to compile manually either.

# macOS example
clang++ -std=c++17 -I/usr/local/share/rpgc/runtime \
  myprog.cpp \
  -I$(brew --prefix)/include -L$(brew --prefix)/lib -lodbc \
  -o myprog

Debugging in VS Code

rpgc -g compiles with full debug symbols and generates .vscode/launch.json for the CodeLLDB extension. The debugger maps execution back to your original .rpgle source.

One-time setup — install the VS Code extension for your platform:

Platform	Extension
macOS / Linux	CodeLLDB (`vadimcn.vscode-lldb`)
Windows	C/C++ (`ms-vscode.cpptools`)

Per-program:

rpgc -g program.rpgle -o program

Then open the folder in VS Code, set breakpoints in your .rpgle file, and press F5.

Multi-Module Programs

OpenRPG supports splitting programs across multiple source files using CTL-OPT NOMAIN with EXPORT/IMPORT and EXTPROC:

rpgc -c module.rpgle          # compile module to module.o
rpgc -shared ORD100.rpgle     # a program others call: ORD100.so / .dylib / .dll
rpgc main.rpgle module.o      # compile main and link with module

See the User's Guide for details.

Documentation

User's Guide — Full language reference with examples, browsable on the wiki (source: docs/GUIDE.md)
IBM i Conformance Results — Every test program compiled with IBM's own ILE RPG compiler on a real IBM i: which compiled, which didn't, and IBM's reason. Updated by the IBM i conformance workflow each time it runs.
TODO.md — Feature tracker

Highlights

Full free-format RPG IV support (declarations, control flow, expressions)
Fixed-format (column-based) source, mixable with free-format in one file
Display files (WORKSTN) with subfiles, via the OpenDSPF compiler
Program-described flat files (I-specs and O-specs)
90+ built-in functions
Data structures (QUALIFIED, TEMPLATE, DIM, LIKEDS, OVERLAY, POS)
Procedures with prototypes, optional parameters (*NOPASS, *OMIT)
Enumerations (DCL-ENUM)
Varying-dimension arrays (DIM(*VAR), DIM(*AUTO))
Date/time arithmetic with all format constants
MONITOR/ON-ERROR error handling, *PSSR, ON-EXIT
Multi-module support (NOMAIN, EXPORT, IMPORT, EXTPROC)
Conditional compilation (/IF, /DEFINE, /COPY); rpgc predefines *OPENRPG, so /IF DEFINED(*OPENRPG) marks lines only rpgc compiles
Embedded SQL via ODBC (SQLite, PostgreSQL, MySQL, SQL Server, Db2)
Record-level access (READ, WRITE, CHAIN, UPDATE, DELETE, SETLL, SETGT) via ODBC, with PREFIX on DCL-F to rename a file's fields
DATA-INTO / DATA-GEN for JSON parsing and generation
Source-level debugging in VS Code (rpgc -g)

Building from Source

If you prefer to build from source rather than using a pre-built package:

Prerequisites: C++17 compiler (clang++ or g++), Flex, Bison.

# macOS
brew install flex bison

# Linux (Debian/Ubuntu)
sudo apt install flex bison g++

# Windows (x86_64) — use MSYS2 MINGW64 shell
pacman -S mingw-w64-x86_64-gcc mingw-w64-x86_64-flex mingw-w64-x86_64-bison make

# Windows (ARM64) — use MSYS2 CLANGARM64 shell (no native gcc for this target)
pacman -S mingw-w64-clang-aarch64-toolchain flex bison make

git clone --recursive https://github.com/danlong005/OpenRPG.git
cd OpenRPG
make
sudo make install        # installs to /usr/local

Trademarks

RPG, RPG IV, ILE, ILE RPG, RPG/400, IBM i, AS/400, and Db2 are trademarks or registered trademarks of International Business Machines Corporation in the United States, other countries, or both. Other product and service names might be trademarks of IBM or other companies.

This project is an independent, clean-room implementation. It is not affiliated with, endorsed by, sponsored by, or otherwise associated with IBM. References to IBM products and technologies are made solely for the purpose of describing compatibility and interoperability (nominative fair use).

License

MIT — see LICENSE for details.

Name		Name	Last commit message	Last commit date
.github/workflows		.github/workflows
OpenDSPF @ 0382c9d		OpenDSPF @ 0382c9d
assets		assets
docs		docs
examples		examples
installer		installer
runtime		runtime
scripts		scripts
src		src
tests		tests
.gitignore		.gitignore
.gitmodules		.gitmodules
CUSTMENU.dspfd		CUSTMENU.dspfd
LICENSE		LICENSE
Makefile		Makefile
README.md		README.md
TODO.md		TODO.md
ibmi-conformance-baseline.json		ibmi-conformance-baseline.json
ibmi-conformance-differences.md		ibmi-conformance-differences.md
ibmi-conformance-report.txt		ibmi-conformance-report.txt
ibmi-execution-baseline.json		ibmi-execution-baseline.json
ibmi-execution-differences.md		ibmi-execution-differences.md

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OpenRPG

IBM i compatibility

Installation

macOS

Linux

Windows

Quick Start

Usage

Database Connectivity

Platform Setup

macOS

Linux — Ubuntu / Debian

Linux — RHEL / Fedora

Windows

Connecting from RPG Source

PostgreSQL Example

Supported Databases

Compiling SQL Programs Manually

Debugging in VS Code

Multi-Module Programs

Documentation

Highlights

Building from Source

Trademarks

License

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OpenRPG

IBM i compatibility

Installation

macOS

Linux

Windows

Quick Start

Usage

Database Connectivity

Platform Setup

macOS

Linux — Ubuntu / Debian

Linux — RHEL / Fedora

Windows

Connecting from RPG Source

PostgreSQL Example

Supported Databases

Compiling SQL Programs Manually

Debugging in VS Code

Multi-Module Programs

Documentation

Highlights

Building from Source

Trademarks

License

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