fpc-msgbase

A unified Free Pascal library for reading and writing classic BBS message bases.

Implements every supported format from the FTSC specifications and the original format authors' published documentation, behind one polymorphic API (TMessageBase). BBS software, mail tossers, message editors, and utilities can target a single interface regardless of the underlying format on disk.

Supported formats

Format	Files	Backend unit
Hudson	MSGINFO/IDX/HDR/TXT/TOIDX.BBS	ma.fmt.hudson.pas
JAM	*.JHR *.JDT *.JDX *.JLR	ma.fmt.jam.pas
Squish	*.SQD *.SQI *.SQL	ma.fmt.squish.pas
FTS-1 MSG	numbered *.MSG per directory	ma.fmt.msg.pas
FTN PKT	*.pkt (Type-2 / 2+ / 2.2)	ma.fmt.pkt.pas
PCBoard	*.MSG + *.IDX	ma.fmt.pcboard.pas
EzyCom	MH#####.BBS / MT#####.BBS	ma.fmt.ezycom.pas
GoldBase	MSGINFO/IDX/HDR/TXT/TOIDX.DAT	ma.fmt.goldbase.pas
Wildcat 4	WC SDK databases	ma.fmt.wildcat.pas

Features

• One TMessageBase abstract class — read, write, pack, reindex through the same methods regardless of format.
• Lossless two-area message model. TUniMessage = Body (just the message text) + Attributes (key/value bag holding from/to/subject/dates/ addresses/MSGID/SEEN-BY/PATH and per-format extras). Same shape as RFC 822 email. Round-trip preservation enforced by the test suite.
• Capabilities API — base.SupportsAttribute('attr.returnreceipt') lets UIs hide controls the underlying backend has no slot for. Each backend publishes its key list via ClassSupportedAttributes. Full per-format matrix in docs/attributes-registry.md.
• Per-user High-Water Mark — base.GetHWM('NetReader') / base.SetHWM(...) plus auto-bump via base.ActiveUser. Tossers and scanners register as named users in the format's native lastread file (.JLR for JAM, .SQL for Squish), so multiple consumers coexist without colliding. Unsupported formats return -1 honestly.
• Layered locking: in-process TRTLCriticalSection + cross-process advisory lock (fpflock on Unix, LockFileEx on Windows, .LCK sentinel fallback)
  • the existing fmShareDenyWrite / fmShareDenyNone share modes.
• Event hooks for logging, progress, and status reporting.
• TPacketBatch worker pool for tossers that need to process many .pkt files concurrently while serialising writes per destination base.
• Path / filename auto-derivation per format from a base directory plus optional area tag.

Building

Native Linux:

fpc -Fusrc -Fusrc/formats examples/example_read.pas

Lazarus package:

lazbuild fpc-msgbase.lpk

The repo includes a fpc.cfg template covering the multi-target build (i386-go32v2, i386-win32, i386-linux, i386-os2).

Layout

src/                ma.api, ma.types, ma.events, ma.lock, ma.paths, ma.batch
src/formats/        ma.fmt.<format>.pas — one per supported format
docs/               architecture, locking semantics, format notes
tests/              FPCUnit tests, sample data
examples/           small CLI programs that double as smoke tests

Unit-name convention follows the Fimail style: ma.<category>.<name>.pas (ma. is the library's namespace prefix; the project was originally named message_api, hence ma). All units use {$mode objfpc}{$H+}.

Documentation

• docs/API.md — full API reference with examples
• docs/architecture.md — layered design + Body/Attributes contract
• docs/attributes-registry.md — canonical attribute keys + per-format support matrix
• docs/ftsc-compliance.md — spec notes
• docs/format-notes/ — per-format quirks

Status

Early development. APIs may move until 1.0.

0.2 is a breaking change vs 0.1. TUniMessage lost its 13 named fields (WhoFrom/WhoTo/Subject/MsgNum/Attr/etc.) in favour of a strict Body + Attributes two-area model. Migration:

{ before }                       { after }
msg.WhoFrom                       msg.Attributes.Get('from')
msg.Subject := 'foo';             msg.Attributes.SetValue('subject', 'foo');
msg.Attr := MSG_ATTR_LOCAL;       msg.Attributes.SetBool('attr.local', true);
msg.OrigAddr                      msg.Attributes.GetAddr('addr.orig')
msg.DateWritten                   msg.Attributes.GetDate('date.written')

This change makes the unified API lossless — kludges (MSGID, SEEN-BY, PATH, etc.) round-trip cleanly, where 0.1 silently dropped them. See docs/attributes-registry.md for the full key catalog.

Format backends are spec-driven implementations validated against real-world sample bases.