[fpc-devel] [Lazarus] Changes to TProcess

[zeljko]

On 03. 01. 2024. 14:28, Michael Van Canneyt via lazarus wrote:
> 
> Hello,
> 
> I merged a significant evolution of the TProcess component to FPC trunk.
> 
> Until recently, there were 2 options for TProcess when starting a new
> process:
> 
> - use the parent process standard input/output/error
> - use pipes to make the standard input/output/error available as streams 
> in the parent process.
> 
> This has been enhanced with the following new possibilities:
> 
> - For the new process, the standard input/output/error can be configured 
> separately.
> 
> - You can specify a filename as input/output/error.
>    (additionally, you can rewrite or append to the file in case of output)
> 
> - You can specify a custom I/O handle as input/output/error
>    (e;g. at least on unix, you can pass a socket handle)
> 
> - You can specify the null file (/dev/null on unixes or NULL on windows)
> 
> - You can specify another TProcess instance.
> 
> The last option means that you can now chain processes, just as the 
> command shell does.
> 
> So the equivalent of the following chain of commands:
> 
> command <input.txt | sed s/delphi/FPC/g > file.txt
> 
> would then be
> 
>    Proc.Executable:='command';
>    Proc.InputDescriptor.FileName:='input.txt';
>    Proc2.Executable:='sed';
>    Proc2.Parameters.Add('s/delphi/FPC/g');
>    Proc2.OutputDescriptor.FileName:='file.txt';
>    Proc.OutputDescriptor.Process:=Proc2;
>    Proc2.Execute;
>    Proc.execute;
> 
> Needless to say, the component remains backwards compatible.
> 
> There is now a testsuite for the TProcess command, so everything was 
> tested.
> but nothing beats testing in the wild, so I would appreciate it if people
> could test it and provide feedback.


Great feature :)

Thanks Michael

zeljko