function F_OVERWRITE_IF_DIFF()
{
    local FILE_PATH=$1
    local DEST_DIR=$2
 
    # Error handling
    if [ ! -f "${FILE_PATH}" ]; then 
        echo "Error: Input file: ${FILE_PATH}: no such file. Aborted!"
        exit 1
    fi;
    if [ ! -d "${DEST_DIR}" ]; then 
        echo "Error: Destination directory: ${DEST_DIR}: no such directory. Aborted!"
        exit 1
    fi;
 
 
    FILE_PATH=$(readlink -ev "${FILE_PATH}")
    DEST_DIR=$(readlink -ev "${DEST_DIR}")
 
    local FILENAME=$(basename "${FILE_PATH}")
    if [ -f "${DEST_DIR}/${FILENAME}" ]; then
 
        if ! cmp "${FILE_PATH}" "${DEST_DIR}/${FILENAME}" >/dev/null 2>&1; then
            yes | mv "${FILE_PATH}" "${DEST_DIR}"
        fi
 
    else
        mv "${FILE_PATH}" "${DEST_DIR}"
    fi
}
 
# Call the function.
F_OVERWRITE_IF_DIFF myfile.txt /to/destination/dir/