#!/bin/sh

# The MIT License (MIT)
#
# Copyright © 2020-2025 pacman64
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the “Software”), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.


# processes [options...]
#
# Show all current processes as a table of tab-separated values (TSV), whose
# first line has the column names.
#
# All data come from running the `ps` command: when not given any options,
# the default is to run `ps aux --sort=pid`.
#
# Besides the usual `ps`-specific options, this script offers easier-to-use
# options
#
#   --c      reverse-sort entries by latest sampled CPU use
#   --cpu    reverse-sort entries by latest sampled CPU use
#
#   --h      show this help message
#   --help   show this help message
#
#   --m      reverse-sort entries by latest sampled RSS (memory) use
#   --mem    reverse-sort entries by latest sampled RSS (memory) use
#   --rss    reverse-sort entries by latest sampled RSS (memory) use
#
#   --u      sort/group entries by user
#   --user   sort/group entries by user



case "$1" in
    -h|--h|-help|--help)
        awk '/^# +processes /, /^$/ { gsub(/^# ?/, ""); print }' "$0"
        exit 0
    ;;
esac

for arg in "$@"; do
    case "${arg}" in
        --) break;;
        # a|u|x|au|ax|ua|ux|xa|xu) select="${select}${arg}";;
        # aux|axu|uax|uxa|xau|xua) select="${select}${arg}";;
        --c|--cpu) sort="--sort=-%cpu,-rss";;
        --i|--id|--p|--pid) sort="--sort=pid";;
        --m|--mem|--rss) sort="--sort=-rss,-%cpu";;
        --u|--user) sort="--sort=user,-%cpu,-rss";;
        # --u|--user) sort="--sort=user,-rss,-%cpu";;
        --sort=*) sort="${arg}";;
        *) select="${select}${arg}";;
    esac
done

res="$(ps ${select:-aux} ${sort:---sort=pid})"

echo "${res}" | awk '
    NR == 1 { cut = match($0, /(CMD|COMMAND)$/) ? RSTART : 0 }
    cut == 0 { print; next }
    {
        lead = substr($0, 1, cut - 1)
        gsub(/^ +| +$/, "", lead)
        gsub(/ +/, "\t", lead)
        printf "%s\t%s\n", lead, substr($0, cut)
    }
'