pmaports/main/postmarketos-android-recovery-installer/update-binary

#!/sbin/ash
# shellcheck shell=dash

# Copyright 2017 Attila Szöllősi
#
# This file is part of postmarketos-android-recovery-installer.
#
# postmarketos-android-recovery-installer 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, either version 3 of the License, or
# (at your option) any later version.
#
# postmarketos-android-recovery-installer 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 postmarketos-android-recovery-installer.  If not, see <http://www.gnu.org/licenses/>.

# Print fail information
OUTFD=$2
fail_info() {
	FAIL_MSG="Failed. Check /tmp/postmarketos/pmos.log for more info!"
	echo -n -e "ui_print $FAIL_MSG\n" > /proc/self/fd/"$OUTFD"
	echo -n -e "ui_print\n" > /proc/self/fd/"$OUTFD"
}
# Create working directory
mkdir /tmp/postmarketos/
# Extract and start the installer script
busybox unzip "$3" "bin/pmos_install" "bin/pmos_install_functions" "install_options" -d /tmp/postmarketos/
/tmp/postmarketos/bin/pmos_install "$2" "$3" || { fail_info ; exit 1 ; }