#!/bin/bash
# ------------------------------------------------------------------------------
# Copyright (c) 2013-2022 Geoffray Levasseur <fatalerrors@geoffray-levasseur.org>
# Protected by the BSD3 license. Please read bellow for details.
#
# * Redistribution and use in source and binary forms,
# * with or without modification, are permitted provided
# * that the following conditions are met:
# *
# *   Redistributions of source code must retain the above
# *   copyright notice, this list of conditions and the
# *   following disclaimer.
# *
# *   Redistributions in binary form must reproduce the above
# *   copyright notice, this list of conditions and the following
# *   disclaimer in the documentation and/or other materials
# *   provided with the distribution.
# *
# *   Neither the name of the copyright holder nor the names
# *   of any other contributors may be used to endorse or
# *   promote products derived from this software without
# *   specific prior written permission.
# *
# * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
# * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
# * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
# * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
# * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
# * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
# * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
# * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
# * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
# * OF SUCH DAMAGE.
# ------------------------------------------------------------------------------

# ------------------------------------------------------------------------------
# Search processes matching the given string
# Usage: ppg <string>
ppg()
{
    if [[ "$1" == "-h" || "$1" == "--help" ]]; then
        printf "ppg: Search processes matching the given string.\n\n"
        printf "Usage: ppg <string>\n\n"
        printf "Options:\n"
        printf "\t-h, --help\t\tDisplay this help screen\n"
        return 0
    fi
    if [[ -z "$1" ]]; then
        disp E "Usage: ppg <string>"
        return 1
    fi
    ps -edf | grep "$@" | grep -v "grep $@"
}
export -f ppg
# ------------------------------------------------------------------------------


# ------------------------------------------------------------------------------
# List processes owned by a specific user
# Usage: ppu <username>
ppu()
{
    if [[ "$1" == "-h" || "$1" == "--help" ]]; then
        printf "ppu: List processes owned by a specific user.\n\n"
        printf "Usage: ppu <username>\n\n"
        printf "Options:\n"
        printf "\t-h, --help\t\tDisplay this help screen\n"
        return 0
    fi
    if [[ -z "$1" ]]; then
        disp E "Usage: ppu <username>"
        return 1
    fi

    # -u lists processes for a specific user
    # -o provides a clean, standard output format
    ps -u "$1" -o pid,user,%cpu,%mem,start,time,command
}
export -f ppu
# ------------------------------------------------------------------------------


# ------------------------------------------------------------------------------
# List processes by exact command name (no path/parameters)
# Usage: ppn <command_name>
ppn()
{
    if [[ "$1" == "-h" || "$1" == "--help" ]]; then
        printf "ppn: List processes by exact command name (no path/parameters).\n\n"
        printf "Usage: ppn <command_name>\n\n"
        printf "Options:\n"
        printf "\t-h, --help\t\tDisplay this help screen\n"
        return 0
    fi
    if [[ -z "$1" ]]; then
        disp E "Usage: ppn <command_name>"
        return 1
    fi

    # -e: select all processes
    # -o: specify custom output columns (PID and Command name)
    # grep -w: ensures exact word matching so 'bash' doesn't match 'dbash'
    ps -eo pid,comm | grep -w "$1"
}
export -f ppn
# ------------------------------------------------------------------------------


# ------------------------------------------------------------------------------
# Get PID list of the given process name
# Usage: ppid <process_name [process_name2 ...]>
gpid()
{
    if [[ "$1" == "-h" || "$1" == "--help" ]]; then
        printf "gpid: Get PID list of the given process name.\n\n"
        printf "Usage: gpid <process_name [process_name2 ...]>\n\n"
        printf "Options:\n"
        printf "\t-h, --help\t\tDisplay this help screen\n"
        return 0
    fi
    if [[ -z "$1" ]]; then
        disp E "Usage: gpid <process_name [process_name2 ...]>"
        return 1
    fi
    [[ $UID -eq 0 ]] && local psopt="-A"
    [[ $# -eq 1 ]] && local single=1
    for pid in $@; do
        local result=$(ps $psopt | grep $pid | awk '{print $1}' | sed "s/\n/ /")
        if [[ $single ]]; then
            [[ $result ]] && echo "${result//$'\n'/ }"
        else
            [[ $result ]] && echo "$pid: ${result//$'\n'/ }"
        fi
    done
    [[ $result ]] || return 1
}
export -f gpid
# ------------------------------------------------------------------------------


# ------------------------------------------------------------------------------
# Kill all processes owned by the given users (kill user)
# Usage: ku <username1 [username2 ...]>
ku()
{
    if [[ "$1" == "-h" || "$1" == "--help" ]]; then
        printf "ku: Kill all processes owned by the given users.\n\n"
        printf "Usage: ku <username1 [username2 ...]>\n\n"
        printf "Options:\n"
        printf "\t-h, --help\t\tDisplay this help screen\n"
        return 0
    fi
    if [[ -z "$1" ]]; then
        disp E "Usage: ku <username1 [username2 ...]>"
        return 1
    fi
    for u in $@; do
        killall -u "$u"
    done
}
export -f ku
# ------------------------------------------------------------------------------


# ------------------------------------------------------------------------------
# Kill all children of a process then the process (kill tree)
# Usage: kt <pid> [kill_options]
kt()
{
    if [[ "$1" == "-h" || "$1" == "--help" ]]; then
        printf "kt: Kill all children of a process then the process (kill tree).\n\n"
        printf "Usage: kt <pid> [kill_options]\n\n"
        printf "Options:\n"
        printf "\t-h, --help\t\tDisplay this help screen\n"
        return 0
    fi
    if [[ -z "$1" ]]; then
        disp E "Usage: ppg <string>"
        return 1
    fi

    local parent_pid="$1"
    shift
    if [[ "$parent_pid" == "0" || "$parent_pid" == "1" ]]; then
        disp E "Safety abort: Refusing to kill PID $parent_pid (system critical)."
        return 1
    fi

    children_pids=$(pgrep -P "$parent_pid")

    for pid in $children_pids; do
        kt "$pid" "$@" || break
    done
    kill "$@" "$parent_pid"
}
# ------------------------------------------------------------------------------


# EOF