check_env.sh

#!/bin/bash

# Preamble

PROGNAME=$(basename $0)

function error_exit
{
	echo "${PROGNAME}: ${1:-"Unknown Error"}" 1>&2
	exit ${2:-1}
}

# Argument validation

[[ -z "$1" ]] && error_exit "Variable Name to check must be provided" 1
[[ -z "$2" ]] && error_exit "Expected variable value must be provided" 2
NAME=$1
EVALUE=$2

# Get real value
RVALUE="${!NAME}"

# Compare
[[ "$RVALUE" = "$EVALUE" ]] || error_exit "Real Value [$RVALUE] different from expected value [$EVALUE]" 3