Program return value ?

[George Marshall]

Hi all, I'm trying to get the exit code of a program
I want to exec in a python script in a portable manner.

I've read that both os.system and os.spawnl are not a
portable solution.

I tried the os.popen() function and I got the program's exit
code with the close() method.

p=os.popen("ret urn_a_exit_code .sh")
retval=p.close( )

The only problem is that it doesn't return negative values.

What is your experience with that ?

Thanks in advance.

[Hallvard B Furuseth]

Re: Program return value ?

George Marshall wrote:
[color=blue]
> Hi all, I'm trying to get the exit code of a program
> I want to exec in a python script in a portable manner.
> (...)
> The only problem is that it doesn't return negative values.[/color]

On a Unix system, the exit status from a program is one byte, which on
8-bit systems can have values from 0 to 255. So if the program does
exit(-1), the exit status is (unsigned char)-1 == 255.

I don't know how this works on other operating system, but in any case I
imagine your problem is with the possible range of the exit status, not
with python. Maybe your program should write a value to stdout (or some
other file) instead, so python could read the number.

--
Hallvard