"Найти текст в текстовом файле и заменить его" - как реализовать вот это? поиск строки в текстовом файле: | Код |
uses SysUtils, Classes;
function GrabLine(const AFileName: string; ALine: Integer): string;
var
fs: TFileStream;
buf: packed array[0..4095] of Char;
bufRead: Integer;
bufPos: PChar;
lineStart: PChar;
tmp: string;
begin
fs := TFileStream.Create(AFileName, fmOpenRead);
try
Dec(ALine);
bufRead := 0;
bufPos := nil;
{ read the first line specially }
if ALine = 0 then
begin
bufRead := fs.Read(buf, SizeOf(buf));
if bufRead = 0 then
raise Exception.Create('Line not found');
bufPos := buf;
end else
while ALine > 0 do
begin
{ read in a buffer }
bufRead := fs.Read(buf, SizeOf(buf));
if bufRead = 0 then
raise Exception.Create('Line not found');
bufPos := buf;
while (bufRead > 0) and (ALine > 0) do
begin
if bufPos^ = #10 then
Dec(ALine);
Inc(bufPos);
Dec(bufRead);
end;
end;
{ Found the beginning of the line at bufPos... scan for end.
2 cases:
1) we'll find it before the end of this buffer
2) it'll go beyond this buffer and into n more buffers }
lineStart := bufPos;
while (bufRead > 0) and (bufPos^ <> #10) do
begin
Inc(bufPos);
Dec(bufRead);
end;
{ if bufRead is positive, we'll have found the end and we can leave. }
SetString(Result, lineStart, bufPos - lineStart);
{ determine if there are more buffers to process }
while bufRead = 0 do
begin
bufRead := fs.Read(buf, SizeOf(buf));
lineStart := buf;
bufPos := buf;
while (bufRead > 0) and (bufPos^ <> #10) do
begin
Inc(bufPos);
Dec(bufRead);
end;
SetString(tmp, lineStart, bufPos - lineStart);
Result := Result + tmp;
end;
finally
fs.Free;
end;
end;
function GrabLine2(const s: string; ALine: Integer): string;
var
sl: TStringList;
begin
sl := TStringList.Create;
try
sl.LoadFromFile(s);
Result := sl[ALine - 1]; // index off by one
finally
sl.Free;
end;
end;
begin
Writeln(GrabLine(ParamStr(1), StrToInt(ParamStr(2))));
Writeln(GrabLine2(ParamStr(1), StrToInt(ParamStr(2))));
end.
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замена строки: | Код |
procedure FileReplaceString(const FileName, searchstring, replacestring: string);
var
fs: TFileStream;
S: string;
begin
fs := TFileStream.Create(FileName, fmOpenread or fmShareDenyNone);
try
SetLength(S, fs.Size);
fs.ReadBuffer(S[1], fs.Size);
finally
fs.Free;
end;
S := StringReplace(S, SearchString, replaceString, [rfReplaceAll, rfIgnoreCase]);
fs := TFileStream.Create(FileName, fmCreate);
try
fs.WriteBuffer(S[1], Length(S));
finally
fs.Free;
end;
end;
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[Delphi]Поиск и замена строки в текстовом файле 
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