FpOpen function

Declaration

function FpOpen(path: PAnsiChar; flags: cint; Mode: TMode): cint

Description

FpOpen opens a file in Path with flags flags and mode Mode One of the following:

O_RdOnly

File is opened Read-only

O_WrOnly

File is opened Write-only

O_RdWr

File is opened Read-Write

The flags may beOR-ed with one of the following constants:

O_Creat

File is created if it doesn't exist.

O_Excl

If the file is opened with O_Creat and it already exists, the call will fail.

O_NoCtty

If the file is a terminal device, it will NOT become the process' controlling terminal.

O_Trunc

If the file exists, it will be truncated.

O_Append

the file is opened in append mode. Before each write, the file pointer is positioned at the end of the file.

O_NonBlock

The file is opened in non-blocking mode. No operation on the file descriptor will cause the calling process to wait till.

O_NDelay

Idem as O_NonBlock

O_Sync

The file is opened for synchronous IO. Any write operation on the file will not return until the data is physically written to disk.

O_NoFollow

if the file is a symbolic link, the open fails. (Linux 2.1.126 and higher only)

O_Directory

if the file is not a directory, the open fails. (Linux 2.1.126 and higher only)

Path can be of type PChar or String. The optional mode argument specifies the permissions to set when opening the file. This is modified by the umask setting. The real permissions are Mode and not umask. The return value of the function is the file descriptor, or a negative value if there was an error.

Errors

Extended error information can be retrieved using fpGetErrno.

See also

• FpClose
• FpRead
• FpWrite
• FpFTruncate
• FpLSeek

Example: ex19

Program Example19;

{ Program to demonstrate the fpOpen, fpwrite and fpCLose functions. }

Uses BaseUnix;

Const Line : String[80] = 'This is easy writing !';

Var FD : Cint;

begin
  FD:=fpOpen ('Test.dat',O_WrOnly or O_Creat);
  if FD>0 then
    begin
    if length(Line)<>fpwrite (FD,Line[1],Length(Line)) then
      Writeln ('Error when writing to file !');
    fpClose(FD);
    end;
end.