Re: fhpd <program>

[Andrew Cagney <cagney@redhat.com>]

Tim Moore wrote:
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> Andrew Cagney wrote:
>   
>> Hi Stan,
>>
>> I'm not sure what you mean by never regains I/O control.
>>
>> One key issue though is wiring the child process up to a
>> frysk.sys.PseudoTerminal - otherwise the process and fhpd will be
>> fighting over control of the terminal.  Don't forget that there are two
>> cases to handle:
>>     
> I checked in changes that implement the "run" command in the CLI command
> line. It will be quite easy to adapt the fhpd program to pass an
> argument to run a program named in its arguments. This works well for
> our simple looping test cases, but I also didn't think about the
> terminal issue.
>   
>> - fhpd command line where it clearly should create the PTY
>>     
> What should the other side of the pty be bound to? An xterm?
>   

Good question.

For the text only case, it could start a terminal (there's a gtk object 
accessable to frysk for doing that) but I would expect a user running 
just the command line to be doing so because they do not want to use X 
and do not want or have access to an X based terminal.  Instead the 
controlling-pty would be managed by the HPD.  That will allow the HPD to 
control the child's output - say only displaying it when there is no HPD 
command input, and, when specified, switching all I/O to the child.  The 
HPD spec discusses this.

I would expect that just that mode will prove sufficient - it covers the 
common case of a program doing printf level I/O.   For a program 
attempting complex terminal manipulations, graphics, or modes (e.x., 
vi), a dedicated terminal is a requirement (saving all terminal state is 
not technically possible).  In that senario, it will be better to direct 
the user towards a gnome interface where a dedicated terminal is 
provided.  An option like <<frysk --hpd>>, to start the HPD under GNOME, 
might be useful.

Andrew

>> - UI where the pty will be part of a Terminal panel and the code should
>> bind the created process to that
>>     
>
> Tim
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