TProcess EOF - CloseInput

[Snify]

Hello together

I have the following function to "read" a regular string from stdin:

Code: Pascal  [Select][+][-]

1. function GetStdIn: string;
2. var
3.    tmp: string;
4. begin
5.   result := '';
6.   while not EOF do begin
7.     readln (tmp);
8.     if EOF then begin
9.       result:= result + tmp;
10.     end else begin
11.       result:= result + tmp + LineEnding;
12.     end;
13.   end;
14. end;    

The full test program looks like this:

Code: Pascal  [Select][+][-]

1. begin
2.   writeln (StdErr, 'FIRST ERROR LINE');
3.   writeln ('This line and the following stdin detection is on stdout');
4.   writeln ('Stdin was:', LineEnding, GetStdIn);
5.   writeln (StdErr, 'This is on stderror');
6.   writeln ('Regular stdout again');
7.   // end of program
8. end.

                               
I am not sure if my function is correct.
This works like a charm if I use the above function in a shell like this:

Code: Pascal  [Select][+][-]

1. printf "row1\nrow2\n..." | ./project1

However when I use the TProcess Class with the WriteInput Method, the process locks.

This is what I use to execute my program and try to read and write to the pipes:
(some of the code is taken from https://wiki.freepascal.org/Executing_External_Programs)

Code: Pascal  [Select][+][-]

1. MyProcess               := TProcess.Create(NIL);    
2. MyProcess.Executable    := 'project1'; // the program with the "GetStdIn" function
3. MyProcess.Options               := MyProcess.Options + [poPassInput, poUsePipes];
4. MyProcess.Execute;
5. mystring                                := 'Hello Lazarus';
6. MyProcess.Input.Write(mystring[1], Length(mystring));
7. MyProcess.CloseInput; // does not trigger EOF?!
8.  
9. // NumBytesAvailable is always 0 for output and stderr
10. while MyProcess.Running or (MyProcess.Output.NumBytesAvailable > 0) or
11. (MyProcess.Stderr.NumBytesAvailable > 0) do
12. begin
13.     while MyProcess.Output.NumBytesAvailable > 0 do
14.     begin
15.         ReadCount := Min(512, MyProcess.Output.NumBytesAvailable); //Read up to buffer, not more
16.         MyProcess.Output.Read(CharBuffer, ReadCount);
17.     end;
18.                                  
19.     while MyProcess.Stderr.NumBytesAvailable > 0 do
20.     begin
21.         ReadCount := Min(512, MyProcess.Stderr.NumBytesAvailable); //Read up to buffer, not more
22.         MyProcess.Stderr.Read(CharBuffer, ReadCount);
23.     end;
24. end;
25. MyProcess.Free;

                                                                                 
The binary path etc. is simplified here and executes just as it should be.
If I remove the whole stdin stuff, it works just fine.

Can someone spot my error?

Thank you in advance

[Snify]

I just figured out the problem.
Thank you.

I needed to avoid "poPassInput".
This causes to use the stdin from the "parent" process instead of it's own stdin.