scripts/src/eprefix-activate

#!/usr/bin/env bash


# This file is part of scripts.

# scripts is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, version 3.

# scripts is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.

# You should have received a copy of the GNU General Public License
# along with scripts.  If not, see <https://www.gnu.org/licenses/>.

# Original author: Maciej Barć <xgqt@riseup.net>
# Copyright (c) 2020, src_prepare group
# Licensed under the GNU GPL v3 License

# Source this to enter the Eprefix environment
# Like this for example:
# $ source $HOME/gentoo/eprefix-activate


# >>> Set eprefix

EPREFIX=${EPREFIX:-${HOME}/gentoo}
export EPREFIX


# >>> Funcion definitions

command_exists() {
    if command -v "${1}" >/dev/null
    then
        return 0
    else
        return 1
    fi
}

if command_exists tput
then
    eprefix_good="$(tput bold)$(tput setaf 2)*$(tput sgr0)"
    eprefix_bad="$(tput bold)$(tput setaf 1)*$(tput sgr0)"
    eprefix_warn="$(tput bold)$(tput setaf 3)*$(tput sgr0)"
else
    eprefix_good="*"
    eprefix_bad="*"
    eprefix_warn="*"
fi

eprefix_addpath() {
    if [ -d "${1}" ]
    then
        PATH=${1}:${PATH}
        export PATH
    else
        printf "%s\n" "${eprefix_warn} ${1} not found" >> /dev/stderr
    fi
}

eprefix_addman() {
    if [ -d "${1}" ]
    then
        MANPATH=${1}:${MANPATH}
        export MANPATH
    else
        printf "%s\n" "${eprefix_warn} ${1} not found" >> /dev/stderr
    fi
}

eprefix_packages() {
    if [ -d "${EPREFIX}/var/db/pkg" ]
    then
        find "${EPREFIX}"/var/db/pkg/*/* -type d | wc -l
    fi
}

eprefix_world() {
    if [ -f "${EPREFIX}/var/lib/portage/world" ]
    then
        wc -l < "${EPREFIX}/var/lib/portage/world"
    fi
}


# >>> Checks

# Exit if script is not sourced
case ${-} in
    *i* )
        :
        ;;
    * )
        printf "%s\n" \
            "${eprefix_bad} Error: not a login shell" \
            "${eprefix_bad} Run: source ${0}" \
            ">>> Exiting the shell" >> /dev/stderr
        exit 1
        ;;
esac

# Exit if eprefix does not exist
if [ ! -d "${EPREFIX}" ]
then
    printf "%s\n" \
        "${eprefix_bad} No ${EPREFIX} found!" \
        ">>> Exiting the shell" >> /dev/stderr
    sleep 3
    exit 1
fi


# >>> PATH setup

# Add directories to PATH
eprefix_addpath "${EPREFIX}/bin"
eprefix_addpath "${EPREFIX}/opt/bin"
eprefix_addpath "${EPREFIX}/sbin"
eprefix_addpath "${EPREFIX}/tmp/bin"
eprefix_addpath "${EPREFIX}/tmp/usr/bin"
eprefix_addpath "${EPREFIX}/usr/bin"
eprefix_addpath "${EPREFIX}/usr/local/bin"
eprefix_addpath "${EPREFIX}/usr/local/sbin"
eprefix_addpath "${EPREFIX}/usr/sbin"

# Add manpages
eprefix_addman "${EPREFIX}/usr/local/share/man"
eprefix_addman "${EPREFIX}/usr/share/binutils-data/x86_64-pc-linux-gnu/2.34/man"
eprefix_addman "${EPREFIX}/usr/share/man"


# >>> General env setup

# Process .sh files
for sh in "${EPREFIX}"/etc/profile.d/*.sh
do
    # shellcheck disable=SC1090 disable=SC1091
    [ -r "${sh}" ] && source "${sh}"
done
unset sh

# Set Portage shell
CONFIG_SHELL="${EPREFIX}/bin/bash"
export CONFIG_SHELL

# Misc env vars
CONFIG_PROTECT_MASK="${CONFIG_PROTECT_MASK} ${EPREFIX}/etc/ca-certificates.conf"
CONFIG_PROTECT_MASK="${CONFIG_PROTECT_MASK} ${EPREFIX}/etc/gentoo-release"
CONFIG_PROTECT_MASK="${CONFIG_PROTECT_MASK} ${EPREFIX}/etc/sandbox.d"
CONFIG_PROTECT_MASK="${CONFIG_PROTECT_MASK} ${EPREFIX}/etc/terminfo"
GCC_SPECS=""
LANG="en_US.utf8"
export CONFIG_PROTECT_MASK
export GCC_SPECS
export LANG

# Set umask
umask 022


# >>> Use Eprefix's tools

# We just use "which" because we put Eprefix's PATHs first
# before the system ones
EDITOR="$(command -v nano)"
PAGER="$(command -v less)"
export EDITOR
export PAGER


# >>> Emerge options

# Sandbox does not work well on Prefix
# Bug: 490246
FEATURES="${FEATURES} -usersandbox -sandbox"
export FEATURES

# Check if we are on a prefix profile
printf "\n"
if command_exists eselect
then
    eprofile="$(eselect profile show)"

    if [[ "${eprofile}" == *prefix* ]]
    then
        printf "%s\n" "${eprefix_good} ${eprofile}"
    else
        printf "%s\n" "${eprefix_bad} You are not on a prefix profile" >> /dev/stderr
    fi

    unset eprofile
else
    printf "%s\n" "${eprefix_bad} Could not determine running profile" >> /dev/stderr
fi


# >>> Finish

printf "\n%s\n" \
    ">>> Sourced the eprefix script\n" \
    "${eprefix_good} Prefix:    ${EPREFIX}" \
    "${eprefix_good} Packages:  $(eprefix_packages)" \
    "${eprefix_good} In World:  $(eprefix_world)" \
    "${eprefix_good} Have fun!  ;-)"


if command_exists emerge
then
    printf "\n%s\n" ">>> Environment ready"
else
    printf "\n%s\n" \
        "${eprefix_bad} Could not locate emerge" \
        "${eprefix_bad} Environment may be broken" \
        ">>> Continuing anyway..." >> /dev/stderr
fi


# >>> Cleanup
unset eprefix_good
unset eprefix_bad
unset eprefix_warn