fpc-msgbase/examples/example_read.pas

{
  example_read.pas - open a message base via the unified API,
                     walk every message, dump a one-line summary.

  usage:  example_read <format> <path>

    format  : hudson | jam | squish | msg | pcboard | ezycom |
              goldbase | auto
    path    : directory or basename the backend expects

  Example:
    example_read hudson /home/ken/fidonet/msg/hudson
}

program example_read;

{$mode objfpc}{$H+}

uses
  SysUtils,
  mb.types, mb.events, mb.api,
  mb.fmt.hudson,   mb.fmt.hudson.uni,
  mb.fmt.jam,      mb.fmt.jam.uni,
  mb.fmt.squish,   mb.fmt.squish.uni,
  mb.fmt.msg,      mb.fmt.msg.uni,
  mb.fmt.pcboard,  mb.fmt.pcboard.uni,
  mb.fmt.ezycom,   mb.fmt.ezycom.uni,
  mb.fmt.goldbase, mb.fmt.goldbase.uni;

type
  TLogger = class
    procedure OnLog(Level: TMsgEventType;
                    const Source, Msg: AnsiString);
  end;

procedure TLogger.OnLog(Level: TMsgEventType;
                        const Source, Msg: AnsiString);
begin
  WriteLn('[', EventTypeToStr(Level), '] ', Source, ': ', Msg);
end;

var
  gLogger: TLogger;

function ParseFormat(const S: string; out AFormat: TMsgBaseFormat;
                     out AAuto: boolean): boolean;
begin
  AAuto := False;
  Result := True;
  case LowerCase(S) of
    'hudson':   AFormat := mbfHudson;
    'jam':      AFormat := mbfJam;
    'squish':   AFormat := mbfSquish;
    'msg':      AFormat := mbfMsg;
    'pcboard':  AFormat := mbfPCBoard;
    'ezycom':   AFormat := mbfEzyCom;
    'goldbase': AFormat := mbfGoldBase;
    'wildcat':  AFormat := mbfWildcat;
    'auto':     AAuto := True;
  else
    Result := False;
  end;
end;

procedure Usage;
begin
  WriteLn('Usage: example_read <format> <path>');
  WriteLn('   formats: hudson jam squish msg pcboard ezycom goldbase wildcat auto');
  Halt(2);
end;

var
  fmtName: string;
  path:    string;
  fmt:     TMsgBaseFormat;
  auto:    boolean;
  base:    TMessageBase;
  msg:     TUniMessage;
  i, n:    longint;
begin
  if ParamCount < 2 then Usage;
  fmtName := ParamStr(1);
  path    := ParamStr(2);

  if not ParseFormat(fmtName, fmt, auto) then Usage;

  try
    if auto then
      base := MessageBaseOpenAuto(path, momReadOnly)
    else
      base := MessageBaseOpen(fmt, path, momReadOnly);
  except
    on E: Exception do begin
      WriteLn('error: ', E.Message);
      Halt(1);
    end;
  end;

  if base = nil then begin
    WriteLn('error: could not detect format at ', path);
    Halt(1);
  end;

  gLogger := TLogger.Create;
  base.Events.OnLog := @gLogger.OnLog;

  if not base.Open then begin
    WriteLn('error: Open returned False (base files missing?)');
    base.Free;
    Halt(1);
  end;

  try
    n := base.MessageCount;
    WriteLn('format: ', MSG_BASE_FORMAT_NAME[base.Format],
            '   path: ', base.BasePath,
            '   messages: ', n);
    for i := 0 to n - 1 do
      if base.ReadMessage(i, msg) then
        WriteLn(Format('%5d  %-20s -> %-20s  %s',
                       [msg.Attributes.GetInt('msg.num'),
                        Copy(msg.Attributes.Get('from'), 1, 20),
                        Copy(msg.Attributes.Get('to'),   1, 20),
                        Copy(msg.Attributes.Get('subject'), 1, 40)]));
  finally
    base.Close;
    base.Free;
    gLogger.Free;
  end;
end.