[Lazarus] Can't copy TMemoryStream to TProcess.Input

[Mattias Gaertner]

On Sat, 6 Apr 2013 11:55:41 -0300
Leonardo M. Ramé <l.rame at griensu.com> wrote:

> On 2013-04-06 00:04:07 +0200, Mattias Gaertner wrote:
> > On Fri, 5 Apr 2013 17:33:22 -0300
> > Leonardo M. Ramé <l.rame at griensu.com> wrote:
> > 
> > > Hi, it must be that I've been working for more than 8 hrs but I can't find where the problem is...
> > > 
> > > I need to pass a file via stdIn to TProcess, then capture the StdOut. This
> > > program should do what I expect, but, instead it hangs after writing aprox
> > > 293000 bytes to Proc.Input stream.
> > > 
> > > Can you take a look at it?. 
> > > 
> > > program test;
> > > 
> > > {$mode objfpc}{$H+}
> > > 
> > > uses
> > >   SysUtils, Classes, 
> > >   process,
> > >   math;
> > > 
> > > 
> > > function CompressLZMA(AStream: TMemoryStream): TMemoryStream;
> > > var
> > >   Proc: TProcess;
> > >   lBuffer: array [0..2048] of byte;
> > >   ReadCount: integer;
> > >   lPos: LongInt;
> > > begin
> > >   Result := TMemoryStream.Create;
> > >   AStream.Position:= 0;
> > >   writeln('-1-');
> > >   Proc := TProcess.Create(nil); //Create a new process
> > >   try
> > >     Proc.Executable := '/usr/bin/lzma'; //Run lzma
> > >     Proc.Parameters.Add('--compress');
> > >     Proc.Options := [poUsePipes, poStderrToOutPut];
> > >     Proc.Execute; 
> > > 
> > >     writeln(format('Writing %d bytes...', [AStream.Size]));
> > > 
> > >     lPos := 0;
> > >     while(lPos < AStream.Size) do
> > >     begin
> > >       writeln(format('Pos: %d - Size: %d', [lPos, AStream.Size]));
> > >       ReadCount := AStream.Read(lBuffer, SizeOf(lBuffer));
> > >       Proc.Input.Write(lBuffer, ReadCount);
> > >       lPos := lPos + ReadCount;
> > 
> > After every write to Input, read all available from Output and StdErr.
> > 
> > Mattias
> > 
> 
> Thanks Mattias, I went a step further.
> 
> Sadly now I'm getting an "unexpected end of input" error when I try to
> decompress the generated file using "lzma -d -c output.lzma >
> output.dcm".

Check return value of Proc.Input.Write.
And call Proc.CloseInput when your input was written completely.


Mattias