Shell script to convert environment variables list file to single line to use on the command line

loadenv.sh

#!/bin/sh

if [ $# -lt 1 ]; then
    echo "usage: loadenv filename"
    exit 2
fi

HASH="#"

for ENV_FILE in "$@"; do
    #echo "file: $ENV_FILE"
    if [ -f $ENV_FILE ]; then
        #echo "loading: $ENV_FILE"
        while read line || [ -n "$line" ]; do
            if [[ "$line" == *=* ]] && [[ "$line" != ${HASH}* ]]; then
                LOAD_ENV=$LOAD_ENV" "$line
            fi
        done < "$ENV_FILE"
    fi
done

echo $LOAD_ENV