[GRASS-dev] python question - how to test if file is executable in path?

GRASS GRASS developer
1

I’d like to test if a program is executable or not (i.e., in this case, whether it is in the PATH) in a python script.

Any suggestions as to how to do this in a way that does not raise a Python error?

Michael

C. Michael Barton, Professor of Anthropology
Director of Graduate Studies
School of Human Evolution & Social Change
Center for Social Dynamics & Complexity
Arizona State University

Phone: 480-965-6262
Fax: 480-965-7671
www: <www.public.asu.edu/~cmbarton>

2

Michael Barton wrote:

I'd like to test if a program is executable or not (i.e., in this
case, whether it is in the PATH) in a python script.

Any suggestions as to how to do this in a way that does not raise a
Python error?

This is probably about as good as you're likely to get:

import os
import os.path

def find_exe(name):
    try:
        path = os.getenv("PATH")
  if path == None:
            path = os.defpath
        for dir in path.split(os.pathsep):
            file = os.path.join(dir, name)
            if os.access(file, os.X_OK):
                return file
    except:
        pass
    return None

This isn't 100% reliable, but nothing is. Ultimately, you don't really
know if you can execute something until you try. Particularly on
Windows.

--
Glynn Clements <glynn@gclements.plus.com>