Советы по Delphi
Unix-строки (чтение и запись Unix-файлов)
Данный модуль позволяет читать и записывать файлы формата Unix.
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unit StreamFile; interface Uses SysUtils; Procedure AssignStreamFile (var F : Text ; Filename : String); implementation Const BufferSize = 128; Type TStreamBuffer = Array [1..High (Integer)] of Char; TStreamBufferPointer = ^TStreamBuffer; TStreamFileRecord = Record Case Integer Of 1: ( Filehandle : Integer; Buffer : TStreamBufferPointer; BufferOffset : Integer; ReadCount : Integer; ); 2: ( Dummy : Array [1 .. 32] Of Char ) End; Function StreamFileOpen (var F : TTextRec) : Integer; Var Status : Integer; Begin With TStreamFileRecord (F.UserData) Do Begin GetMem (Buffer, BufferSize); Case F.Mode Of fmInput: FileHandle := FileOpen (StrPas (F.Name), fmShareDenyNone); fmOutput: FileHandle := FileCreate (StrPas (F.Name)); fmInOut: Begin FileHandle := FileOpen (StrPas (F.Name), fmShareDenyNone Or fmOpenWrite or fmOpenRead); If FileHandle <> -1 Then status := FileSeek (FileHandle, 0, 2); { Перемещаемся в конец файла. } F.Mode := fmOutput; End; End; BufferOffset := 0; ReadCount := 0; F.BufEnd := 0; { В этом месте подразумеваем что мы достигли конца файла (eof). } If FileHandle = -1 Then Result := -1 Else Result := 0; End; End; Function StreamFileInOut (var F : TTextRec) : Integer; Procedure Read (var Data : TStreamFileRecord); Procedure CopyData; Begin While (F.BufEnd < Sizeof (F.Buffer) - 2) And (Data.BufferOffset <= Data.ReadCount) And (Data.Buffer [Data.BufferOffset] <> #10) Do Begin F.Buffer [F.BufEnd] := Data.Buffer^ [Data.BufferOffset]; Inc (Data.BufferOffset); Inc (F.BufEnd); End; If Data.Buffer [Data.BufferOffset] = #10 Then Begin F.Buffer [F.BufEnd] := #13; Inc (F.BufEnd); F.Buffer [F.BufEnd] := #10; Inc (F.BufEnd); Inc (Data.BufferOffset); End; End; Begin F.BufEnd := 0; F.BufPos := 0; F.Buffer := ''; Repeat Begin If (Data.ReadCount = 0) Or (Data.BufferOffset > Data.ReadCount) Then Begin Data.BufferOffset := 1; Data.ReadCount := FileRead (Data.FileHandle, Data.Buffer^, BufferSize); End; CopyData; End Until (Data.ReadCount = 0) Or (F.BufEnd >= Sizeof (F.Buffer) - 2); Result := 0; End; Procedure Write (var Data : TStreamFileRecord); Var Status : Integer; Destination : Integer; II : Integer; Begin With TStreamFileRecord (F.UserData) Do Begin Destination := 0; For II := 0 To F.BufPos - 1 Do Begin If F.Buffer [II] <> #13 Then Begin Inc (Destination); Buffer^[Destination] := F.Buffer [II]; End; End; Status := FileWrite (FileHandle, Buffer^, Destination); F.BufPos := 0; Result := 0; End; End; Begin Case F.Mode Of fmInput: Read (TStreamFileRecord (F.UserData)); fmOutput: Write (TStreamFileRecord (F.UserData)); End; End; Function StreamFileFlush (var F : TTextRec) : Integer; Begin Result := 0; End; Function StreamFileClose (var F : TTextRec) : Integer; Begin With TStreamFileRecord (F.UserData) Do Begin FreeMem (Buffer); FileClose (FileHandle); End; Result := 0; End; Procedure AssignStreamFile (var F : Text ; Filename : String); Begin With TTextRec (F) Do Begin Mode := fmClosed; BufPtr := @Buffer; BufSize := Sizeof (Buffer); OpenFunc := @StreamFileOpen; InOutFunc := @StreamFileInOut; FlushFunc := @StreamFileFlush; CloseFunc := @StreamFileClose; StrPLCopy (Name, FileName, Sizeof(Name) - 1); End; End; end. |
