CMD executable PATH for ProDOS's BASIC.SYSTEM

Build with ca65

Installation:

• Copy target to ProDOS disk
• From BASIC.SYSTEM prompt, run: -PATH from STARTUP (or by hand)

Usage:

PATH prefix     - set search path(s) - colon delimited
PATH            - view current search path(s)
cmdname         - load and execute named CMD, if in PATH

Once set, binary files of type CMD in the specified directories can be invoked by name.

• CMD file is loaded at $4000 and invoked; should return (rts) on completion.
• The command line will be present at $200 (GETLN input buffer).
• Supports multi-segment, colon-separated paths, e.g. /hd/cmds:/hd2/more.cmds

Example:

] -/hd/path              - install it
] PATH /hd/cmds:/h2/bin  - set PATH
] PATH                   - verify path
/hd/cmds
] BELL                   - will invoke /hd/cmds/BELL if present
] HELLO                  - will invoke /hd/cmds/HELLO if present

Notes:

• Allocates a permanent buffer to store the code and path (2 pages)
• Can be invoked as lower case (e.g. path ...)
• Applesoft BASIC commands are unaffected (but can't be CMD names)
• Search order when a command is typed:
  • ProDOS BASIC.SYSTEM intrinsics (CAT, PREFIX, etc)
  • AppleSoft keywords (LIST, PRINT, etc)
  • CMD files in paths, in listed order