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发信人: lofe ()感激生活(), 信区: BorlandDev
标  题: 怎样读写unix文件
发信站: 哈工大紫丁香 (Mon Sep  4 16:08:21 2000), 转信

//下面的单元实现了Unix文件的读写

------------------------------------------------------------------------

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) ; { Move to end of file. }
� F.Mode := fmOutput ;
� End ;
� End ;
� BufferOffset := 0 ;
� ReadCount := 0 ;
� F.BufEnd := 0 ;� { If this is not here it thinks we are at 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;

--
※ 修改:．haojs 于 Sep  4 16:04:56 修改本文．[FROM: bbs.hit.edu.cn]
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※ 转寄:．武汉白云黄鹤站 bbs.whnet.edu.cn．[FROM: bbs.hit.edu.cn]

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☆ 来源:．哈工大紫丁香 bbs.hit.edu.cn．[FROM: haojs.bbs@bbs.whnet.]