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I am trying to pass arguments to a bash script from python. The official documentation says that you need to separate with comma but I'm using it and it does not work.

subprocess.run(["/bin/bash test.sh", "hello", "dog", "3" ], shell=True)

In the bash script I have this basic code:

echo "The number of arguments is: $#"

The result is: The number of arguments is: 0

Any advice? I decided it to pass as a string (Not so clean), putting a space " "+"hello" + " dog" + " 3"

Regards,

wjandrea
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Alberto B
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1 Answers1

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You have two options.

  1. call it with a list of arguments but without shell=True:

    subprocess.run(["/bin/bash", "test.sh", "hello", "dog", "3" ])

  2. pass a single string with shell=True:

    subprocess.run("/bin/bash test.sh hello dog 3", shell=True)

From docs of subprocess:

On POSIX with shell=True, the shell defaults to /bin/sh. If args is a string, the string specifies the command to execute through the shell. This means that the string must be formatted exactly as it would be when typed at the shell prompt. This includes, for example, quoting or backslash escaping filenames with spaces in them. If args is a sequence, the first item specifies the command string, and any additional items will be treated as additional arguments to the shell itself.

More info about shell flag: Actual meaning of 'shell=True' in subprocess

wjandrea
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Matej
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  • For me, secound solution worked fine. I was looking for it some time. If someone want to pass variables like that, good solution is (in python >=3.6 probably) `subprocess.run(f"/bin/bash/test.sh {var1} {var2}", shell=True)`. First solution looks interesting but it doesn't work. I think, if we pass many strings, shell should be `True` – Kawson May 10 '21 at 22:58