#!/bin/bash
# Use /usr/local/bin/bash for Solaris systems
# Use /bin/bash for Linux systems
#
# Name: list-update
# Version: 0.2
# Created: 2007-05-30
# Last Updated: 2014-03-25
# Written By: Jim Cameron <sripts(at)moonpoint.com>
#
# Location: 
# http://support.moonpoint.com/downloads/computer_languages/bash/list-update
#
# Description: Updates the specified mailing list
#
# Usage: list-update list
#
# List is a text file containing just the email address for list members.
# It is created from a spreadsheet that contains member information.
# The column containing the email addresses is saved as a text file,
# which is the input for this script.  Since many members have not provided 
# email addresses, there will be many blank lines in the original file.
#
# The filename specified on the command line will be replaced with the
# results of the processes run by this script.
#
# Changes: version 0.2 added command to change file permissions to 644

if [ -z "$1" ]
then
  echo "Usage $0 list"
  echo ""
  echo "List is the unprocessed mailing list text file, which will be"
  echo "updated. A backup file will be created with the same name, but"
  echo "with .bak added at the end of the filename"
  exit
fi

# Check for existence of file
if [ ! -e "$1" ]
then
  echo "Error! $1 does not exist"
  exit
fi

# Create a backup for the original file
cp -p $1 $1.bak
echo "Backup file created: $1.bak"
echo ""

# Convert the text file, which is in DOS format to Unix format.
# DOS and Windows systems use CRLF at the end of lines, whereas
# Unix systems use only LF.
#
# If the original file and the converted file  are  the  same,
# dos2unix   will  rewrite  the original file after converting it.
dos2unix $1 $1

# Display number of lines in original file
echo -n "Number of lines in original file:"
wc -l $1
echo ""

# Remove blank lines
cat $1 | sed -e '/^$/d' > $1.tmp

# Sort file, storing results in original file
sort -o $1 $1.tmp

# Show duplicate entries
echo "Duplicated Entries"
uniq -d $1
echo ""

# Remove duplicate entries
uniq $1 $1.tmp

# Check for invalid email addresses
echo "Invalid Email Addresses"
grep -v '@' $1.tmp
grep -v "\." $1.tmp
# Look for entries where the last character may have been omitted
# A presumption is made that members won't have non-US country codes
# as part of the FQDN, i.e., though co represents Columbia and ne
# is the country code for Niger, no email address with .co or .ne 
# at the end of the address is expected.
grep "co$" $1.tmp
grep "or$" $1.tmp
grep "ne$" $1.tmp
echo ""

# Put valid email addresses in original file
grep '@' $1.tmp | grep "\." | grep -v "co$" | grep -v "or$" | grep -v "ne$" >$1

# Display number of valid, unique email addresses
echo -n "Number of valid, unique email addresses:"
wc -l $1
echo ""

# Delete the temporary file
rm $1.tmp

# Set permissions to give owner r/w permission with group and world having
# read permission
chmod 644 $1

echo "$1 contains the updated list."