system() API sometimes calls sh -c "my_command"

QNX USERS QNX6 - OS
1

Hi,

In my app code, I’m using system() API to execute “my_command” like this:

int iRetVal = system( “my_command” );

Now, most of the time it works. But sometimes, the system() API doesn’t return at all. When I get suspicious of that, I use pidin to find out whats happening? It shows me this:

xxxxx (PID) sh- c my_command

I thought that the command “sh -c my_command” is the usual way system() API works. So, to test it, I used pidin when thing were running perfectly.
To my astonishment, the results were:

xxxxx (PID) my_command

This result is also the same when I run it from the command line.

Can anybody tell me whats wrong here?

I’m using QNX 6.4.0

2

I’m guessing that sh “becomes” you process when it is running properly ( that is what exec() does ). But when it’s not running sh may be unable to start your command?

3

I think the question is, what state is “sh -c my_command” in? Is it Reply blocked to some process? Maybe Proc?

4

Thanks mario.
If that is true, then what shall be done to avoid it?

5

To avoid what? You don’t know why it is happening yet. When you find out, you will know how to avoid it.

6

Thanks maschoen.
I’ll try to reproduce the problem and see the thread state then.