Source Physical Files and Source Members

Learning Objective

By the end of this lesson, you will understand what a source physical file is, what a source member is, and how source code for programs like RPGLE and CLLE is typically organized and stored on IBM i.

Simple Explanation

In the Physical Files and Logical Files lesson, you learned that IBM i stores data in physical files, each made up of records with a defined structure. A source physical file is a specialized kind of physical file used to store source code rather than typical business data.

Where a regular physical file might hold customer records or order records, a source physical file holds programming source code, such as RPGLE or CLLE source. The key difference is that a source physical file does not hold just one program's worth of source code. Instead, it is divided into separate source members, where each member is its own named unit of source code, similar in spirit to an individual file inside a folder, except that here the "folder" is the source physical file itself and stored inside a library like any other object.

For example, a source physical file named QRPGLESRC is a common, though not required, convention for storing RPGLE source members, and a library might contain dozens or hundreds of individual source members inside that one source physical file, each representing a different program's source code.

Why It Matters

Understanding source physical files and source members clarifies how IBM i developers actually organize source code, which can look unfamiliar if you are used to environments where each program's source code is simply its own separate file on disk. On IBM i, many programs' source code commonly lives together inside one source physical file, organized as separate members, rather than as many separate files scattered across a folder structure. This matters directly for practical, everyday tasks like finding, opening, or editing a specific program's source code.

Practical Example

Imagine a library called MYAPPSRC that contains a source physical file named QRPGLESRC. Inside that one source physical file are several source members, including one named CUSTINQ holding the source code for a customer inquiry program, and another named ORDENTRY holding the source code for an order entry program.

A developer who wants to edit the customer inquiry program's source code opens the CUSTINQ member specifically, inside the QRPGLESRC source physical file, inside the MYAPPSRC library, rather than looking for a separate file named CUSTINQ somewhere on disk. This is a simplified, illustrative example rather than a specific real system's exact contents, but it reflects a very common, everyday IBM i organizational pattern.

Common Confusions

"Is a source physical file the same as a regular physical file?" They share the same underlying physical file object type, *FILE, that you learned about in the Common IBM i Object Types lesson, but a source physical file is specifically structured and used to hold source code organized into members, rather than typical business data records.

"Is a source member its own separate object, like a program or a file?" No. A source member exists inside a source physical file; it is not a standalone object with its own object type. You always refer to a source member in the context of the source physical file, and the library, that contains it.

"Does every IBM i shop use the exact same source physical file names, like QRPGLESRC?" Names like QRPGLESRC are common conventions, not a strict, universal requirement. Different organizations may use different source physical file names for organizing their RPGLE, CLLE, or other source code, though following common naming conventions makes source code easier for other developers to find and understand.

Quick Recap

• A source physical file is a specialized physical file used to store programming source code rather than typical business data.
• A source physical file is divided into separate source members, where each member holds one program's source code.
• Source members are not standalone objects; they exist inside a specific source physical file, inside a specific library.
• Common naming conventions, like QRPGLESRC, are widely used but not universally required across every organization.

Try Asking the AI Tutor

Use the AI Tutor to ask follow-up questions about this lesson. For example, try asking:

• "How is a source member different from the compiled program it produces?"
• "What are some other common source physical file naming conventions besides QRPGLESRC?"