problems starting two os:cmd's

[Nico Weling]

Hi all,

I have problems starting an os:cmd in two different processes.

Process 1:
   ...
   ScreenOutput = os:cmd("sendfax -l /dev/mobile0" ++ "  " ++ BNumber ++ "  " ++ Filename"),
   ...

Process 2:
   ...
   ScreenOutput = os:cmd("mgetty -s 115200 /dev/mobile1"),
   ...

If the 1st os:cmd is running the 2nd os:cmd("mg....") will start it's execution if the 1st os:cmd is finished. (both os:cmd's are running in different erlang processes on the same node)

If I start the os:cmd's in the background:

	os:cmd("sendfax -l /dev/mobile0" ++ "  " ++ BNumber ++ "  " ++ Filename" ++ "&"),
	os:cmd("mgetty -s 115200 /dev/mobile1 &"),

it works fine.
If I start the os:cmd's in two different Erlang-shells is also works fine.


Can somebody tell me what happens here and how I can solve this problem.
I am using Erlang R6. (I need to stick to this release) 


Thanks a lot,

best regards Nico.