[SOLVED] Passing Arguments to a Bash Script from a Python Script

gIn_gOut · 06-26-2020, 09:22 AM

G'Day folks

I have a bit of a "sticky wicket" today, which probably needs only a small tweak to resolve.

I'm passing the path to a file, which is discovered in a python script, for further work over in a bash script. Here's the python-side snippet:

Code:

filePath = os.path.realpath(sys.argv[4])
print "This", filePath, "file and path has been identified."
subprocess.Popen(['bash ./receivingScript', filePath], shell=True)

The trouble:

While the string content of "filePath" will expand and print correctly to the console in line 2, and
our bash script, "receivingScript", will be launched as intended in line 3,
the string content of "filePath" is not passed along properly as a commandline argument for "receivingScript".

In sum, whatever gets through to the bash script seems to be completely empty.

Where's the beef?!

Thanks a bunch

dugan · 06-26-2020, 09:47 AM

Assuming this is a current version of Python, and receivingScript is passed properly?

Code:

subprocess.Popen([f'bash ./receivingScript {filePath}'], shell=True)

Note that I'm using an f string.

gIn_gOut · 06-26-2020, 10:15 AM

@dugan:
Thanks for the tip. And yes, "./receivingScript" is passed properly -- all deploys as anticipated.

Furthermore, this type of example works for both sides without issue:

Code:

subprocess.Popen(['bash ./receivingScript someText'], shell=True)

Drawing upon your quick example, I tried both

Code:

subprocess.Popen([f'bash ./receivingScript {filePath}'], shell=True)

and

Code:

subprocess.Popen([f"bash ./receivingScript {filePath}"], shell=True)

Output: "SyntaxError: invalid syntax"
Version: Python 2.7.9

If this is a version/feature issue, is there a workaround solution for this problem? Upgrading on this particular machine would be a hairball...

Thanks again!

gIn_gOut · 06-26-2020, 10:40 AM

Stop the presses!

This appears to work:

Code:

subprocess.Popen(['bash ./receivingScript %s' % (filePath)], shell=True)

Thanks and Cheers!

NevemTeve · 06-26-2020, 03:36 PM

I'd try this change:

Code:

- subprocess.Popen(['bash ./receivingScript', filePath], shell=True)
+ subprocess.Popen(['bash', './receivingScript', filePath], shell=False)

The difference will be visible if filePath contains whitespace characters. Or shell meta-characters like $ \ `

gIn_gOut · 07-03-2020, 04:18 PM

@NevemTeve:

Thanks for stopping by! Added your snippets to my collection

Have a great day...