MOTDfetch/00-motdfetch

#!/usr/bin/env bash
#
# MOTDfetch is a modular and dynamic MOTD replacement
# and a very nice command line information tool for Debian/Ubuntu systems.
#
# repository:   https://git.tkapias.net/tkapias/MOTDfetch
# author:       Tomasz Kapias
# email:        tomasz@tkapias.net
#
# modules path: ./motdfetch.d/
# config paths: $HOME/.config/motdfetch/motdfetch.conf
#               /etc/motdfetch/motdfetch.conf
#
# requirements (modules apart): sudo apt install coreutils bc

# locale env
unset LC_ALL
export LC_MESSAGES=C

# GLOBAL COLORS ######################################################

c_txt="39"
c_txt_emphase="35"
c_txt_deco="97"
c_txt_invert="30"
c_bg="47"
c_danger="31"
c_warning="33"
c_success="32"
c_title="${c_bg};1;${c_txt_invert}m"

# RUN OPTIONS #######################################################

# MODTfetch directory path
SCRIPT_DIR=$(dirname "$(realpath "$0")")

Help()
{
    echo -e "\e[1;${c_txt_emphase}mMOTDfetch\e[1;${c_txt}m is a modular and dynamic MOTD replacement and a very"
    echo -e "nice command line information tool for Debian/Ubuntu systems.\e[0m"
    echo
    echo "Syntax:   bash $SCRIPT_DIR/00-motdfetch [-h] [-f] [-t ARG] [-l]"
    echo
    echo "options:  -h  Print this Help"
    echo "          -f  force execution under heavy load"
    echo "          -t  execute a standalone module with internal sample conf"
    echo "          -l  list available modules files names"    
}

unset option_force_load

# command options and arguments
while getopts "hft:l" option; do
    case $option in
        h) Help
             exit ;;
        f) option_force_load=1;;
        t) # standalone module option
             if [[ -f "$SCRIPT_DIR/motdfetch.d/$OPTARG" ]]; then
                 (. "$SCRIPT_DIR/motdfetch.d/$OPTARG")
                 exit 0
             else
                 echo -e "\e[1;${c_danger}mError\e[0m: Invalid module filename, check the -l option.\n"
                 Help
                 exit 1
             fi;;
        l) # List modules option
             for file in $SCRIPT_DIR/motdfetch.d/*
             do
                 echo -e "$(basename $file) $(head -3 $file|tail -1)"
             done | column -t -s '#'
             exit 0;;
        \?) # Invalid option
             echo -e "\e[1;${c_danger}mError\e[0m: Invalid option"
             Help
             exit 1;;
    esac
done

# CONFIG LOADING ###################################################

userconf="$HOME/.config/motdfetch/motdfetch.conf"
sysconf="/etc/motdfetch/motdfetch.conf"

if [[ -f "$userconf" ]];then
    . "$userconf"
elif [[ -f "$sysconf" ]];then
    . "$sysconf"
else
    echo -e "\e[1;${c_danger}mError\e[0m: no configuration available.\n"
    Help
    exit 1
fi

# EXECUTION #########################################################

## load check
cores=$(/usr/bin/grep -ioPc 'processor\t:' /proc/cpuinfo 2>/dev/null)
if [[ "$cores" -eq "0" ]]; then
    cores=1
fi
threshold="${cores:-1}.5"

echo -e "\n\e[${c_title} MOTDFETCH  \e[0m\n"
if [[ $(echo "`cut -f1 -d ' ' /proc/loadavg` < $threshold" | /usr/bin/bc) -eq 1 || $option_force_load -eq 1 ]]; then
    ### output modules
    for file in $SCRIPT_DIR/motdfetch.d/*
    do
        (. "$file")
    done
    echo
else
    ### too much load for modules, run only 00 & 99 + msg
    module_header_disable=0
    (. $SCRIPT_DIR/motdfetch.d/00-*)
    module_userslog_disable=0
    (. $SCRIPT_DIR/motdfetch.d/99-*)
    echo -e "\n\e[${c_title} WE SKIPPED SOME MODULES  \e[0m\n"
    echo -e "  MOTDfetch skipped some modules because of\n  this \e[1;${c_danger}msystem load\e[0m being higher than \e[1;${c_danger}m$threshold\e[0;${c_warning}m.\e[0m\n"
    echo -e "  \e[1;${c_txt}mBAD ADVICE\e[0m: you can force execution with the option [-f]:\n  # bash $SCRIPT_DIR/00-motdfetch -f\n"
fi