From 18f45619adbdf036043905961ba7342c648de497 Mon Sep 17 00:00:00 2001
From: Iain William Wiseman <iwiseman@bibble.co.nz>
Date: Mon, 5 May 2025 15:40:06 +1200
Subject: [PATCH] Fixed up the hardcode audoio.mp3

---
 .vscode/launch.json |  1 +
 README.md           | 43 +++++++++++++++++++++++++++++++++++++++++--
 id3cobol.cbl        | 27 +++++++++++++++++++++++++++
 3 files changed, 69 insertions(+), 2 deletions(-)

diff --git a/.vscode/launch.json b/.vscode/launch.json
index 0ccc3a0..8df8c17 100644
--- a/.vscode/launch.json
+++ b/.vscode/launch.json
@@ -6,6 +6,7 @@
             "type": "gdb",
             "preLaunchTask": "Build All",
             "request": "launch",
+            "arguments": "audio.mp3",
             "cobcargs": ["-free", "-x", "-g","-debug", "-Wall", "-O0"] ,
             "group": ["id3cobol.cbl"],
             "env": {
diff --git a/README.md b/README.md
index 196a48c..ac3f137 100644
--- a/README.md
+++ b/README.md
@@ -19,6 +19,7 @@ This project is a COBOL-based MP3 ID3 tag reader that parses and displays metada
 - `id3cobol.cbl`: Main COBOL program for reading and parsing MP3 ID3 tags.
 - `zero-ord.cbl`: COBOL module for zero-based ordinal conversion.
 - `Makefile`: Build automation file for compiling and cleaning the project.
+- `audio.mp3`: Sample MP3 file for testing (required for the program to run).
 - `.gitignore`: Specifies files and directories to be ignored by Git.
 
 ## Build Instructions
@@ -43,14 +44,52 @@ This project is a COBOL-based MP3 ID3 tag reader that parses and displays metada
    make distclean
    ```
 
+## Environment Variables
+
+The following environment variables are important for proper execution:
+
+- **COB_LIBRARY_PATH**: Tells COBOL where to find modules
+  ```bash
+  export COB_LIBRARY_PATH=/path/to/workspace:$COB_LIBRARY_PATH
+  ```
+
+- **COB_PRE_LOAD**: Tells COBOL to preload the zero-ord module
+  ```bash
+  export COB_PRE_LOAD=zero-ord
+  ```
+
+- **LD_LIBRARY_PATH**: Helps the Linux dynamic linker find the module
+  ```bash
+  export LD_LIBRARY_PATH=/path/to/workspace:$LD_LIBRARY_PATH
+  ```
+
+These variables are automatically set when using the VS Code debugger.
+
 ## Usage
 
-Run the compiled `id3cobol` program to parse the `audio.mp3` file:
+Run the compiled `id3cobol` program to parse an MP3 file:
+
 ```bash
+# Using default audio.mp3 file:
 ./id3cobol
+
+# Using a specific MP3 file:
+./id3cobol path/to/your/music.mp3
 ```
 
-> **Note**: Ensure you have an `audio.mp3` file in the same directory as the program. This file is required for the program to function.
+> **Note**: Ensure you have an MP3 file with ID3 tags. If no argument is provided, the program will look for `audio.mp3` in the current directory.
+
+## VS Code Integration
+
+This project includes VS Code configuration files:
+
+- **launch.json**: Configures debugging with proper environment variables
+- **tasks.json**: Defines build tasks for compiling the project
+
+To debug in VS Code:
+1. Press F5 or select "Run and Debug" from the left sidebar
+2. Select "COBOL debugger" configuration
+3. The debugger will automatically build and launch the program with audio.mp3
 
 ## Debugging
 
diff --git a/id3cobol.cbl b/id3cobol.cbl
index 49df6f9..0534475 100644
--- a/id3cobol.cbl
+++ b/id3cobol.cbl
@@ -16,6 +16,7 @@ IDENTIFICATION DIVISION.
        *> Debug flag to enable/disable debug prints
        01 WS-DEBUG-MODE      PIC 9 VALUE 1.
 
+       *> Default filename that can be overridden with command-line argument
        01 WS-FILENAME        PIC X(255) VALUE "audio.mp3".
        01 WS-EOF-FLAG        PIC 9 VALUE 0.
        88 WS-EOF         VALUE 1.
@@ -24,6 +25,11 @@ IDENTIFICATION DIVISION.
        01 STOP-READING-FLAG  PIC 9 VALUE 0.
        88 STOP-READING       VALUE 1.
 
+       *> Command line argument handling
+       01 CMD-ARGS.
+          05 CMD-ARG-COUNT    PIC 9(2) COMP-5.
+          05 CMD-ARG-VALUES   PIC X(255) OCCURS 1 TO 10 DEPENDING ON CMD-ARG-COUNT.
+
        *> ID3v2 Header Structure
        01 ID3-HEADER.
            05 ID3-TAG         PIC X(3).      *> Should be "ID3"
@@ -81,6 +87,11 @@ IDENTIFICATION DIVISION.
        PROCEDURE DIVISION.
        MAIN-PARA.
            DISPLAY "Starting MP3-ID3-INFO program".
+           
+           *> Process command-line arguments
+           PERFORM PROCESS-COMMAND-LINE
+           
+           DISPLAY "Analyzing file: " FUNCTION TRIM(WS-FILENAME)
 
            PERFORM OPEN-FILE.
 
@@ -298,3 +309,19 @@ IDENTIFICATION DIVISION.
                END-READ
                MOVE WS-TEMP-BYTE TO BYTES-BUFFER(WS-I:1)
            END-PERFORM.
+
+       *> Process command-line arguments to get the filename
+       PROCESS-COMMAND-LINE.
+           *> Get argument count and values
+           ACCEPT CMD-ARG-COUNT FROM ARGUMENT-NUMBER
+           
+           *> Check if at least one argument was provided
+           IF CMD-ARG-COUNT > 0
+               *> Get the first argument (the filename)
+               ACCEPT CMD-ARG-VALUES(1) FROM ARGUMENT-VALUE
+               
+               *> If argument isn't empty, use it as filename
+               IF CMD-ARG-VALUES(1) NOT = SPACES
+                   MOVE CMD-ARG-VALUES(1) TO WS-FILENAME
+               END-IF
+           END-IF.