Question

I have two simple scripts – I am trying to pass some information (date as input into the python script) to the bash script. Here’s the python one:

#!/usr/local/bin/python

import os
import sys
import subprocess

year = "2012"
month = "5"
month_name = "may"

file = open('date.tmp','w')
file.write(year + "\n")
file.write(month + "\n")
file.write(month_name + "\n")
file.close

subprocess.call("/home/lukasz/bashdate.sh")

And here’s the bash one:

#!/bin/bash

cat /home/lukasz/date.tmp | \
while read CMD; do
    echo -e $CMD
done
rm /home/lukasz/date.tmp

Python script works fine without issues. It calls the bash script but it looks like the while loop just does not run. I know the bash script does run overall because the rm command gets executed and the date.tmp file is removed. However if I comment out the subprocess call in python then run the bash script manually it works fine displaying each line.

Brief explanation of what I am trying to accomplish. I have a python script that exports a very large DB to CSV (almost 300 tables and a few gigs of data) which then calls the bash script to zip the CSVs into one file and move it to another location. I need to pass the month and year supplied to the python script to the bash script.

Answer 1

Instead of writing a temp file, send the values of year, month, and month-name to the bash script as parameters. Ie, in the Python code remove all the lines with file in them, and replace
subprocess.call("/home/lukasz/bashdate.sh")
with
subprocess.call(['/home/lukasz/bashdate.sh', year, month, month_name])

and in the bash script, replace the cat ... rm lines with (eg)
y=$1; m=$2; mn=$3
which puts the year, month, and month-name into shell variables y, m, and mn.