fdOpen

Open file and return file descriptor

Declaration

Source position: line 0

Description

fdOpen opens a file in PathName with flags flags One of the following:

Open_RdOnly

File is opened Read-only

Open_WrOnly

File is opened Write-only

Open_RdWr

File is opened Read-Write

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

Open_Creat

File is created if it doesn't exist.

Open_Excl

If the file is opened with Open_Creat and it already exists, the call wil fail.

Open_NoCtty

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

Open_Trunc

If the file exists, it will be truncated.

Open_Append

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

Open_NonBlock

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

Open_NDelay

Idem as Open_NonBlock

Open_Sync

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

Open_NoFollow

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

Open_Directory

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

PathName 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 filedescriptor, or a negative value if there was an error.

Errors

Errors are returned in LinuxError.

See also

Example

Program Example19;

{ Program to demonstrate the fdOpen, fdwrite and fdCLose functions. }

Uses oldlinux;

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

Var FD : Longint;

begin
  FD:=fdOpen ('Test.dat',Open_WrOnly or Open_Creat);
  if FD>0 then
    begin
    if length(Line)<>fdwrite (FD,Line[1],Length(Line)) then
      Writeln ('Error when writing to file !');
    fdClose(FD);
    end;
end.