Shell Programming and Scripting

I want to send the content of a bash variable as a python argument for processing. The problem is that bash doesn't "expand" the content, just sends the expression.

script.sh

Code:

#!/bin/bash
export RECEIVEDDATE=$(date +"%Y%m%d.%H%M%S")
perl checkdate.py

checkdate.py

Code:

import datetime
import os
import sys
start_date = str(sys.argv[1])
date_1 = datetime.datetime.strptime(start_date, "%Y%m%d.%H%M%S")
# Operate with date_1

Code:

bash script.sh

I admit I am a little perplexed.

Why are you trying to call a Python script invoking it with the binary perl?
How do you know that Bash is not expanding and exporting RECEIVEDDATE?

Code:

export RECEIVEDDATE=$(date +"%Y%m%d.%H%M%S")

I'll say it is the only thing working there.

Guessing that RECEIVEDDATE is the variable that you want to be handed over to / processed by the script, I can't see that neither supplied as a parameter to nor referenced within the script.

My mistake. It's python, not perl. I wrote incorrectly the thread title.


It doesn't matter because we are passing by value, not by reference, which is what @Aia suggests (reading from environment variable). I don't like that way because reading from environment variable is broken in some verison of python, so I prefer passing by value.

Anyway it's solved, because the problem was in the PTY communication. Changing the terminal solved the issue, so it's working properly as expected (bash replaces $RECEIVEDDATE with its contents before sending it as argument to perl).