pac.sh

#!/bin/sh
#
# Author: Indrek Haav
# Source: https://github.com/IndrekHaav/pac

set -eu

RESET="\033[0m"
RED="\033[1;31m"

__usage() {
    cat <<EOF
Usage: $(basename "$0") command

Available commands:
    search <string>         Searches for packages matching <string>
    show <package>          Returns information about <package>
    list --installed        Lists all installed packages
         --manual           Lists all manually installed packages
         --upgradable       Lists all upgradable packages
         --all              Lists all available packages
    depends <package>       Shows a list of dependencies for <package>
    rdepends <package>      Shows a list of packages that depend on <package>
    install <package>       Installs <package>
    download <package>      Downloads <package> to current directory
    cache <package>         Downloads <package> to pacman cache
    remove <package>        Removes <package>
    autoremove <package>    Removes <package> and all its unneeded dependencies
    autoremove              Removes all unneeded dependencies
    clean                   Removes unneeded cached packages and sync database
    upgrade, dist-upgrade   Performs a full system upgrade
EOF
    exit
}

__error() {
    printf "${RED}error:${RESET} %s\n" "$1"
}

__fatal() {
    __error "$1"
    exit 1
}

__require() {
    command -v "$1" >/dev/null || __fatal "install ${2:-$1} to use this functionality"
}

[ "$#" -gt 0 ] || __usage

case "$1" in
    search)
        shift
        [ "$#" -eq 1 ] || __fatal "enter a search term"
        pacman -Ss "$*"
        ;;
    show)
        shift
        [ "$#" -gt 0 ] || __fatal "enter a package name"
        for package in "$@"; do
            pacman -Qi "$package" 2>/dev/null || pacman -Si "$package" 2>/dev/null || __error "package '$package' was not found"
        done
        ;;
    list)
        shift
        case "${1-}" in
            --installed) pacman -Q ;;
            --manual) pacman -Qm ;;
            --upgradable) pacman -Qu ;;
            --all) pacman -Sl ;;
            *) __usage ;;
        esac
        ;;
    depends)
        shift
        __require pactree pacman-contrib
        [ "$#" -gt 0 ] || __fatal "enter a package name"
        pactree -s -d1 -o1 "$@"
        ;;
    rdepends)
        shift
        __require pactree pacman-contrib
        [ "$#" -gt 0 ] || __fatal "enter a package name"
        pactree -r -s -d1 -o1 "$@"
        ;;
    install)
        shift
        [ "$#" -gt 0 ] || __fatal "enter a package name"
        if [ -f "$*" ]; then pacman -U "$*"; else pacman -S "$@"; fi
        ;;
    download)
        shift
        __require curl
        [ "$#" -eq 1 ] || __fatal "enter a package name"
        curl -O "$(pacman -Sp "$*")"
        ;;
    cache)
        shift
        [ "$#" -eq 1 ] || __fatal "enter a package name"
        pacman -Sw "$*"
        ;;
    remove)
        shift
        [ "$#" -gt 0 ] || __fatal "enter a package name"
        pacman -R "$@"
        ;;
    autoremove)
        shift
        pkgs=${*:-$(pacman -Qdtq)}
        # shellcheck disable=SC2086
        [ -n "$pkgs" ] && pacman -Rns $pkgs
        ;;
    update)
        shift
        if [ "$#" -eq 0 ]; then
            __fatal "this command would execute 'pacman -Sy', but partial upgrades are not supported"
        else
            __fatal "this command would execute 'pacman -S $*', but partial upgrades are not supported"
        fi
        ;;
    upgrade|dist-upgrade|full-upgrade)
        pacman -Syu
        ;;
    clean)
        pacman -Sc
        ;;
    *)
        __usage
        ;;
esac