[Parti-discuss] Patch: have "xpra start" optionally start a client application

[Nathaniel Smith]

On Fri, Aug 8, 2008 at 4:23 PM, Robert Tate
<wrtate at users.sourceforge.net> wrote:
>>> import posix
>> ^^ Why use posix explicitly, instead of just os?
>> (On posix systems posix is an alias for os.)
>
> Sorry - this was just a result of my ignorance of python.  I've never
> really written anything in it before.

Sure, everyone starts ignorant; that's why we comment on patches ;-).

(Speaking of which, I actually misspoke in the above -- it should say
that *os* is an alias for *poxix*.  I.e., 'os' is a magic module that
doesn't actually exist on its own, but rather means 'whatever
os-specific module is appropriate on whatever platform I'm on'.)

>> I am struck by another question now, though, i.e.:
>> should  --survive-children be the default or not?
>
> I tend to think that it's better for --survive-children to not be the
> default.  That makes it easy to support a single long-running process
> - which seems like a primary use for xpra.

Sure; and the (an?) other primary use of xpra is for a long-running
session (cf. Ethan's reply).  I guess the issue is that right now what
we do is:

  1) 'xpra start': runs indefinitely
  2) 'xpra start --start-child blah': starts blah and exits with it
  3) 'xpra start --start-child blah --survive-children': starts blah
and runs indefinitely

So if you compare these, 1->2 adds one thing to the command line while
changing two things about the behavior, then 2->3 adds one thing to
the command line while removing one of those behavioral changes.
Which seems a bit counterintuitive; usually you would like a
one-to-one correspondence between syntax and semantics.

On the other hand, practicality beats consistency, and I can't imagine
that typing 'xpra start :DISPLAY --no-survive-children --start-child
<whatever>' all the time would be fun -- nor do I really like the
traditional unix approach of "if god wanted programs to be convenient,
why did he give users shell scripts?".  I guess we could make 'xpra
run <whatever>' a convenience alias?  But I think that to be *really*
convenient you would still need a) autodetection of free displays, so
the user doesn't have to pick these arbitrary magic numbers, and b)
some sort of attach-by-client mechanism (as opposed to
attach-by-magic-number).  And until then, anyone who can deal with all
that can probably deal with writing a little shell script if they want
one.

Okay, I talked myself round to it -- more feedback welcome, but if I
don't get any then I'll make go invert --survive-children and merge to
trunk.

-- Nathaniel