best way of testing a program exists before using it?
blue99 at interia.pl
Mon Sep 11 17:41:30 CEST 2006
Hari Sekhon wrote:
> I am writing a wrapper to a binary command to run it and then do
> something with the xml output from it.
> What is the best way of making sure that the command is installed on the
> system before I try to execute it, like the python equivalent of the
> unix command "which"?
> Otherwise I'd have to do something like:
> if os.system('which somecommand') != 0:
> print "you don't have %s installed" % somecommand
> I know that isn't portable which is why a python solution would be
> better (although this will run on unix anyway, but it'd be nice if it
> ran on windows too).
IMHO this is pretty portable:
>>> def is_on_path(fname):
... for p in os.environ['PATH'].split(os.pathsep):
... if os.path.isfile(os.path.join(p, fname)):
... return True
... return False
More information about the Python-list