Bitshifted exit status from Popen3

[Sean 'Shaleh' Perry]

On 13-Jul-2002 Mike Wakerly wrote:
> Greetings all,
> 
> I am encountering a peculiarity when trying to
> retreive the exit status of a command executed with
> popen2.Popen3.
> 
> The effect is that the returned object in res =
> popen2.Popen3(...) has a res.status value 256x greater
> than it should (eg, bitshited to the left eight places?!)
> 

according to the popen() man page it returns the same value as wait4.  From
that man page:

WEXITSTATUS(status)
              evaluates to the least significant  eight  bits  of
              the  return  code  of  the  child which terminated,
              which may have been set as the argument to  a  call
              to exit() or as the argument for a return statement
              in the main program.  This macro can only be evalu­
              ated if WIFEXITED returned non-zero.

in other words, this is expected behavior.  The shell knows how to interpret it
for you which is why you have never seen it before.