Function fdRead (fd:longint;var buf;size:longint : longint;
fdRead reads at most size bytes from the file descriptor fd, and stores them in buf.
The function returns the number of bytes actually read, or -1 if an error occurred.
No checking on the length of buf is done.
Errors are returned in LinuxError.
fdOpen, fdClose, fdWrite,fdTruncate, fdFlush, fdSeek
Program Example20; { Program to demonstrate the fdRead and fdTruncate functions. } Uses linux; Const Data : string[10] = '12345687890'; Var FD : Longint; l : longint; begin FD:=fdOpen('test.dat',open_wronly or open_creat,octal(666)); if fd>0 then begin { Fill file with data } for l:=1 to 10 do if fdWrite (FD,Data[1],10)<>10 then begin writeln ('Error when writing !'); halt(1); end; fdClose(FD); FD:=fdOpen('test.dat',open_rdonly); { Read data again } If FD>0 then begin For l:=1 to 5 do if fdRead (FD,Data[1],10)<>10 then begin Writeln ('Error when Reading !'); Halt(2); end; fdCLose(FD); { Truncating file at 60 bytes } { For truncating, file must be open or write } FD:=fdOpen('test.dat',open_wronly,octal(666)); if FD>0 then begin if not fdTruncate(FD,60) then Writeln('Error when truncating !'); fdClose (FD); end; end; end; end.