#!/usr/bin/bash

# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
# what:        remove a comment from a single line, in a config file
# author:      klevstul
# started:     mar 2021
#
# requires:    n/a
# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

if [ "$EUID" -eq 0 ]
  then echo "error: do not run as 'root'"
  exit
fi

this_file_name=`basename "$0"`
if [ $# -ne 4 ]; then
    echo "usage: '$this_file_name [{add, remove}] [COMMENT_CHARACTER] [PATTERN] [CONFIG_FILE]'"
    exit 1
fi

operation=$1
comment_character=$2
pattern=$3
config_file=$4

# https://stackoverflow.com/questions/24889346/how-to-uncomment-a-line-that-contains-a-specific-string-using-sed

# add comment character (comment out)
if [ $operation == "add" ]; then
    sed -i "/$pattern/s/^$comment_character*/$comment_character/g" $config_file
fi

# remove comment character (uncomment)
if [ $operation == "remove" ]; then
    sed -i "/$pattern/s/^$comment_character*//g" $config_file
fi