append

#!/bin/bash

# append string, file, stdin to file & avoid doubles

# default options
to_array RPI_APPEND_FILE
to_array RPI_APPEND_APPENDIX


function rpi_append_prerun() {
    # check arguments
    [[ -n "${RPI_APPEND_FILE}" ]] || error "RPI_APPEND_FILE unset. appending to unknown file"
    [[ -n "${RPI_APPEND_APPENDIX}" ]] || error "RPI_APPEND_APPENDIX unset. nothing to append."s
}

function rpi_append_run() {
    local i
    local file
    local appendix
    local string
    # append file to file ?
    i=0
    for appendix in "${RPI_APPEND_APPENDIX[@]}" ; do
        file="${RPI_APPEND_FILE["${i}"]}"
        # appendix is path to file?
        if [[ -f "${appendix}" ]] ; then
            rpi_append_file_to_file "${appendix}" "${file}" || error "rpi_append_file_to_file ${appendix} ${file}"
        # appendix is string
        else
            rpi_append_to_file "${appendix}" "${file}" || error "rpi_append_to_file ${appendix} ${file}"
        fi
        i+=1
    done
}

function rpi_append_description() {
    echo "append string, file, stdin to file & avoid doubles"
}

function rpi_append_help_params() {
    help_param "RPI_APPEND_FILE" "the file to append to"
    help_param "RPI_APPEND_APPENDIX" "string or file which contents should be appended"
}

# ---------------------------------------------------------------------
# append file to file
function rpi_append_file_to_file() {
    local appendix="$1"
    local appendee="$2"
    if [[ -z "${appendix}" ]] || [[ -z "${appendee}" ]] ; then error "missing argument. append" ; fi
    # already appended ?
    [[ -f "${appendix}" ]] && [[ -f "${appendee}" ]] && grep --quiet --fixed-strings --file="${appendix}" "${appendee}" && return 0
    # shellcheck disable=SC2024
    # (sudo is only meant for tee, not redirect)
    # append
    sudo tee -a "${appendee}" < "${appendix}" >/dev/null || error "sudo_append ${appendix} ${appendee}"
}

# append string to file
function rpi_append_to_file() {
    local string="$1"
    local file="$2"
    if [[ -z "${string}" ]] || [[ -z "${file}" ]] ; then error "missing argument. append" ; fi
    # already appended ?
    [[ -f "${file}" ]] && sudo grep --fixed-strings --quiet "${string}" "${file}" && return 0
    # append
    sudo touch "${file}"
    printf "%s\n" "${string}" | sudo tee -a "${file}" >/dev/null || error "sudo_append ${string} ${file}"
    verbose "appended \"${string}\" to \"${file}\""
}

# append input from stdin to file
function rpi_append_stdin() {
    local file="$1"
    [[ -n "${file}" ]] || error "missing argument. append_stdin"
    IFS=''
    while read -r appendix ; do
        rpi_append_to_file "${appendix}" "${file}"
    done
}