popen4 doesn't block?

[Donn Cave]

Quoth Terry Hancock <hancock at anansispaceworks.com>:
...
| Which I *could* translate into python (with os.* calls), but would rather 
| leave as a shell script, since it's simpler that way.  So I have a data 
| structure in Python that defines my package and includes this script as a 
| string.  I then run the script using os.popen4, like this:
|
| i1f, o1f = os.popen4('tcsh')
| i1f.write(script)
| i1f.close()

I don't know that it will solve your problem - doesn't seem to
happen to me - but it would be simpler in some ways if you could
bring yourself to write the script out to disk and then invoke it
by file name.  Eliminates a pipe, and a potential deadlock with it.
Secondly, I think you would be better off to use 'sh' as the shell
(and of course use Bourne shell syntax in the shell commands --
">& megane.log" -> "> megane.log 2>&1".)  sh is universally supported
on UNIX and similar platforms, and it's ordinarily better software
than tcsh for anything but interactive use (if that.)

	Donn Cave, donn at u.washington.edu