Querying and commanding an emacs daemon with nc

message_emacs_daemon.bash

#!/usr/bin/env bash

# usage:
# message_daemon $'(length (frame-list))' /path/to/socketfile
# => 2 

message_daemon () {
    local result
    local socket
    local CMD="${1}"
    if [[ "${#2}" -gt 0 ]]; then
	      socket="${2}"
        read -r result < <(nc -U "${socket}" <<< \
			                        $"-eval ${CMD// /&_}" | \
				                       awk $'FNR == 2 {printf $2}')
        printf '%s' "${result}"
        return 0
    fi
}