join-file

#!/usr/bin/env sh

# Usage: doc/api.md#join-file

# Create an alias
. "${SHELL_API_PATH}"/common/expand-aliases
alias join-file="join_file"

join_file(){
    part_a=""
    part_b=""
    sudo_cmd=""
    target="${1}"

    if [ -z "${1}" ]; then
        echo "join-file: arguments are missing"
        return 127
    fi

    if [ "${1}" = "-a" ] || [ "${1}" = "--auth" ]; then
        sudo_cmd="sudo "
        shift $(( $# > 0 ? 1 : 0 ))
    fi

    # 2 files
    if [ -f "${1}" ] && [ -f "${2}" ]; then
        part_a=$(awk '1' "${1}")
        part_b=$(awk '1' "${2}")
    # File and string
    elif [ -f "${1}" ] && [ -n "${2}" ]; then
        part_a=$(awk '1' "${1}")
        part_b="${2}"
    # String and file
    elif [ -f "${2}" ] && [ -n "${1}" ]; then
        part_a="${1}"
        part_b=$(awk '1' "${2}")
        target="${2}"
    else
        echo "Cannot find target - no such file"
        return 127
    fi

	echo "${part_a}${part_b}" | "${sudo_cmd}"tee "${target}" >/dev/null 2>&1
}