Pascal (Lazarus/Delphi)
Pascal (Lazarus/Delphi)
Read Text at a String Offset from a Remote SFTP File
See more SFTP Examples
Demonstrates the Chilkat SFtp.ReadFileText64s method, which is like ReadFileText64 but takes the byte offset as a decimal string. The arguments are the handle, the offset string, the maximum number of bytes, and the charset.
Background: The string-offset read exists for the same reason as its write counterpart: it lets code in languages without convenient 64-bit integers still address positions in very large files by supplying the offset as text. Functionally it is identical to the
int64 version.Chilkat Pascal (Lazarus/Delphi) Downloads
program ChilkatDemo;
// Demonstrates using the Chilkat Pascal wrapper via the C bridge DLL.
// Builds as a console application under Lazarus (FPC) or Delphi.
{$IFDEF FPC}
{$MODE DELPHI}
{$ENDIF}
{$APPTYPE CONSOLE}
uses
{$IFDEF UNIX}
cthreads,
{$ENDIF}
SysUtils,
CkDllLoader,
Chilkat.SFtp;
// ---------------------------------------------------------------------------
procedure RunDemo;
var
success: Boolean;
sftp: TSFtp;
port: Integer;
password: string;
handle: string;
offset: string;
numBytes: Integer;
text: string;
begin
success := False;
// Demonstrates the SFtp.ReadFileText64s method, which is like ReadFileText64 but takes the byte
// offset as a decimal string. The 1st argument is the handle, the 2nd is the offset string, the
// 3rd is the maximum number of bytes, and the 4th is the charset.
sftp := TSFtp.Create;
// Connect, authenticate, and initialize the SFTP subsystem.
port := 22;
success := sftp.Connect('sftp.example.com',port);
if (success = False) then
begin
WriteLn(sftp.LastErrorText);
Exit;
end;
// Normally you would not hard-code the password in source. You should instead obtain it
// from an interactive prompt, environment variable, or a secrets vault.
password := 'mySshPassword';
success := sftp.AuthenticatePw('mySshLogin',password);
if (success = False) then
begin
WriteLn(sftp.LastErrorText);
Exit;
end;
success := sftp.InitializeSftp();
if (success = False) then
begin
WriteLn(sftp.LastErrorText);
Exit;
end;
handle := sftp.OpenFile('subdir/hugefile.dat','readOnly','openExisting');
if (sftp.LastMethodSuccess = False) then
begin
WriteLn(sftp.LastErrorText);
Exit;
end;
// Supplying the offset as a string is convenient in languages without a native 64-bit integer.
offset := '5000000000';
numBytes := 6;
text := sftp.ReadFileText64s(handle,offset,numBytes,'utf-8');
if (sftp.LastMethodSuccess = False) then
begin
WriteLn(sftp.LastErrorText);
Exit;
end;
WriteLn(text);
success := sftp.CloseHandle(handle);
if (success = False) then
begin
WriteLn(sftp.LastErrorText);
Exit;
end;
sftp.Disconnect();
sftp.Free;
end;
// ---------------------------------------------------------------------------
begin
try
RunDemo;
except
on E: Exception do
WriteLn('Unhandled exception: ', E.ClassName, ': ', E.Message);
end;
WriteLn;
{$IFDEF MSWINDOWS}
WriteLn('Press Enter to exit...');
ReadLn;
{$ENDIF}
end.