Read text files in Delphi - delphi

Question

Hi I am having a problem running a function to read a text file the problem seems to be that my antivirus blocks my delphi console program because when I do for a visual form there is no problem .
Tengos two codes one is this :
function LeerArchivox(const filename: TFileName): String;
var
List: TStringList;
begin
if (FileExists(filename)) then
begin
List := TStringList.Create;
List.Loadfromfile(filename);
Result := List.text;
List.Free;
end;
end;
This goes to perfection but do not want to use the component Classes for the program does not weigh much .
Also I have this :
function leerarchivo(filealeer: string): string;
var
abriendo: TextFile;
lineasleyendo: string;
finaldearchivo: string;
begin
finaldearchivo := '';
AssignFile(abriendo, filealeer);
Reset(abriendo);
while not Eof(abriendo) do
begin
ReadLn(abriendo, lineasleyendo);
finaldearchivo := finaldearchivo + lineasleyendo;
end;
CloseFile(abriendo);
Result := finaldearchivo;
end;
Other code.
function leerarchivo3(archivoaleer: string): string;
const
BUFF_SIZE = $8000;
var
dwread: LongWord;
hFile: THandle;
datafile: array [0 .. BUFF_SIZE - 1] of ansichar;
codigofinal: string;
begin
codigofinal := '';
hFile := CreateFile(PChar(archivoaleer), GENERIC_READ,
FILE_SHARE_READ or FILE_SHARE_WRITE, nil, OPEN_EXISTING,
FILE_ATTRIBUTE_READONLY, 0);
SetFilePointer(hFile, 0, nil, FILE_BEGIN);
Readfile(hFile, datafile, BUFF_SIZE, dwread, nil);
while (dwread > 0) do
begin
Readfile(hFile, datafile, BUFF_SIZE, dwread, nil);
codigofinal := codigofinal + datafile;
end;
Result := codigofinal;
end;
This is the problem because when I use my antivirus deletes it at the time , my question to other alternatives I have to read a text file without using Classes.
Someone can help me?

Answer 1

This code works fine for me as a console application, Delphi 2007, running on Win7 64:
Contents of 'E:\TempFiles\Test.txt':
One
Two
Three
Four
Source:
program Project2;
{$APPTYPE CONSOLE}
uses
SysUtils;
var
Txt: TextFile;
s: string;
AllText: string;
begin
AllText := '';
AssignFile(Txt, 'E:\TempFiles\test.txt');
Reset(Txt);
while not Eof(Txt) do
begin
Readln(Txt, s);
AllText := AllText + s;
// Write out each line; comment out to stop.
Writeln(s);
end;
CloseFile(Txt);
// Write out all content as a single string.
WriteLn(AllText);
ReadLn;
end.
Produces output:
One
Two
Three
Four
OneTwoThreeFour

Answer 2

You can use win32 api.
In one of my apps I do things like that, extend/modify to match your needs. This only use Win32 API and does not lock the file. It's like notepad. When you open a file with notepad it is not locked and can still be written or read by other software.
const
BUFF_SIZE = $8000;
var
dwread:LongWord;
hFile: THandle;
datafile : array [0..BUFF_SIZE-1] of ansichar;
//create file handler
hFile := createfile(PChar(TFilePanel(FilePanelList.Items[i-1]).LongFileName), GENERIC_READ,
FILE_SHARE_READ or FILE_SHARE_WRITE, nil, OPEN_EXISTING, FILE_ATTRIBUTE_READONLY, 0);
//set file pointer to beginning of file
SetFilePointer(hFile, 0, nil, FILE_BEGIN);
//read the file
try
Readfile(hFile, datafile, BUFF_SIZE, dwread, nil);
while (dwread > 0) do
begin
//read/use datafile
Here_do_something_with_datafile;
Readfile(hFile, datafile, BUFF_SIZE, dwread, nil);
end;
finally
closehandle(hFile);
end;

Answer 3

var txt : TextFile;
begin
AssignFile(txt,'filetxt.txt');
ReWrite(filetxt);
Writeln(filetxt,memo1.Lines.Text);
CloseFile(filetxt);
Reset(filetxt);
while not Eof(filetxt) do
begin
Readln(filetxt);
end;
CloseFile(filetxt);

Answer 4

If you don't want to use the Classes unit, only need to operate on this file, and are making a Windows executable, you could use the Windows unit instead and call the Win32 API functions: CreateFile, ReadFile, CloseHandle and related functions.