Re: [Mingw-users] Question about start

Earnie Boyd wrote:
>>  #!/bin/sh
>>  #
>>    'c:/Program Files/Microsoft Office/Office/winword' "$@"
>>  #
>>  # `winword' always forks a background process, even if we don't
>>  # explicitly request it, so wait for it to finish...
>>  #
>>    wait $!
>>  #
>>  # now we can do whatever we need to, after `winword' has finished.
>>  #
>>  ...
>
> Does your example work for 1.0.10?

Yes.

> It doesn't for 1.0.11.

Oh dear.  Something else that's been broken since 1.0.10 :-(  Or could
it be different version dependent behaviour in Windoze or Office?  I'm
on Win2K-SP4, and MS-Office2K, (which I avoid like the plague, as much
as possible :-) -- vim + groff + ghostscript ==> superior documents).

> I'm thinking that maybe all ``native'' children will respond in kind
> if there is no console.  The MSYS children may indeed wait regardless
> if there is a console but I don't know that yet.

Hmm.  Curiously, if we substitute `excel' for `winword' in the example,
it blocks -- `wait' is not needed.  To make it non-blocking, we have to
add the ampersand:

    'c:/Program Files/Microsoft Office/Office/excel' "$@" &

So, if we now modify the original example:

  #!/bin/sh
  #
  # we need the ampersand after `excel', to stop it blocking;
  # if we leave it off, we will not see `winword' start, until
  # the user quits `excel'
  #
    'c:/Program Files/Microsoft Office/Office/excel' "$@" &
  #
  # but, because we did force `excel' to background, we can see
  # both `excel' and `winword' start, and run simultaneously
  #
    'c:/Program Files/Microsoft Office/Office/winword' "$@"
  #
  # `winword' always forks a background process, even if we don't
  # explicitly request it, so wait for it to finish...
  #
    wait $!
  #
  # now, do some more...

With MSYS-1.0.10, this blocks on the `wait $!', until `winword' exits;
it doesn't wait for `excel'.  Of course, this illustrates the difference
between `wait $!' and `wait' without any PID argument; if we replace the
`wait $!' with a simple `wait', this script will wait for *both* `excel'
and `winword', (strictly, *all* children it has spawned in background).

Regards,
Keith.