exec.sh

#!/usr/bin/env bash
#
# Copyright 2021-2024 Gaël PORTAY
#
# SPDX-License-Identifier: LGPL-2.1-or-later
#

unset LD_PRELOAD
unset LD_LIBRARY_PATH

log() {
	level="$1"
	shift

	if [ ! -t 2 ] || [ "${NO_COLOR:-0}" -ne 0 ]
	then
		echo "$level:" "$@" >&2
		return
	fi

	echo -e "\e[31;1m$level:\e[0m" "$@" >&2
}

error() {
	log "Error" "$@"
}

warn() {
	log "Warning" "$@"
}

fixme() {
	log "FIXME" "$@"
}

notice() {
	if [ "${IAMROOT_DEBUG:-0}" -le 1 ]
	then
		return
	fi

	log "Notice" "$@"
}

info() {
	if [ "${IAMROOT_DEBUG:-0}" -le 2 ]
	then
		return
	fi

	log "Info" "$@"
}

path_resolution() {
	if [ "${1:0:1}" != / ]
	then
		echo "$PWD/${1#/*}"
		return
	fi

	echo "$IAMROOT_ROOT/${1#/*}"
}

if [ $# -eq 0 ]
then
	echo "Usage: $0 COMMAND [ARGUMENTS...]" >&2
	error "Too few arguments!"
	exit 1
fi

path="$1"
inchroot_path="$(path_resolution "$path")"
argv0="${_argv0:-$path}"
shift

case "${path##*/}" in
mount|umount)
	notice "not-running" "$argv0" "$@"
	exit 0
	;;
mountpoint)
	args=()
	for i in "$@"
	do
		if [ "${i:0:1}" = "-" ]
		then
			args+=("$i")
		else
			args+=("$IAMROOT_ROOT$i")
		fi
	done
	set -- "${args[@]}"
	unset args

	notice "running" "$inchroot_path" "$@"
	exec "$inchroot_path" "$@"
	;;
build-locale-archive|chfn|chkstat|*.postinst)
	fixme "not-running" "$argv0" "$@"
	exit 0
	;;
busybox)
	info "running" "$inchroot_path" "$@"
	exec "$inchroot_path" "$@"
	;;
# /sbin/ldconfig: Can't create temporary cache file /etc/ld.so.cache~: Permission denied
# /usr/sbin/glibc_post_upgrade: While trying to execute /sbin/ldconfig child exited with exit code 1
glibc_post_upgrade.*)
	if [ -r "$IAMROOT_ROOT/etc/ld.so.conf" ] &&
	   ! grep -q "^include /etc/ld.so.conf.d/*.conf$" "$IAMROOT_ROOT/etc/ld.so.conf"
	then
		echo "include /etc/ld.so.conf.d/*.conf" >"$IAMROOT_ROOT/etc/ld.so.conf"
	fi

	if [ "${IAMROOT_ROOT:-/}" != / ]
	then
		exec "$IAMROOT_ROOT/sbin/ldconfig" -r "$IAMROOT_ROOT"
	fi

	exec "/sbin/ldconfig"
	;;
ldconfig|ldconfig.real)
	if [ "${IAMROOT_ROOT:-/}" != / ]
	then
		args=()
		r=
		f=
		prev=
		for cur in "$@"
		do
			if [ "$prev" = "-r" ]
			then
				args+=("$(path_resolution "$cur")")
				r="${args[-1]}"
			elif [ "$prev" = "-f" ]
			then
				args+=("$(path_resolution "$cur")")
				f="${args[-1]}"
			elif [ "${cur:0:1}" != "-" ]
			then
				args+=("$(path_resolution "$cur")")
			else
				args+=("$cur")
			fi
			prev="$cur"
		done
		unset prev
		unset cur

		if [ ! "$r" ]
		then
			args+=(-r "$IAMROOT_ROOT")
		fi
		unset r

		if [ ! "$f" ]
		then
			f="$IAMROOT_ROOT/etc/ld.so.conf"
		fi

		# Fixes: $IAMROOT_ROOT/usr/sbin/ldconfig: need absolute file name for configuration file when using -r
		if [ -r "$f" ]
		then
			sed -e 's,include ld.so.conf.d/\*.conf,include /etc/ld.so.conf.d/*.conf,' \
			    -i "$f"
		fi
		unset f

		set -- "${args[@]}"
		unset args
	fi

	notice "running" "$inchroot_path" "$@"
	exec "$inchroot_path" "$@"
	;;
gpasswd|passwd|su)
	error "not-running" "$argv0" "$@"
	exit 1
	;;
bbsuid)
	for i in /bin/mount /bin/umount /bin/su /usr/bin/crontab /usr/bin/passwd /usr/bin/traceroute /usr/bin/traceroute6 /usr/bin/vlock
	do
		ln -sf /bin/bbsuid "$IAMROOT_ROOT$i"
	done
	exit 0
	;;
ldd)
	args=()
	for i in "$@"
	do
		if [ "${i:0:1}" = "-" ]
		then
			args+=("$i")
		else
			args+=("$IAMROOT_ROOT$i")
		fi
	done
	set -- "${args[@]}"
	unset args

	# Do not pollute stderr with a warning trace!
	#warn "running" "$inchroot_path" "$@"
	# FIXME: reuse implementation within the library.
	LD_LIBRARY_PATH="$IAMROOT_ROOT/lib:$IAMROOT_ROOT/usr/lib" \
	exec "$inchroot_path" "$@" | sed "s,$IAMROOT_ROOT,,g"
	;;
ld*.so*)
	# Do not pollute stderr with a warning trace!
	# warn "running" "$inchroot_path" "$@"
	exec "$inchroot_path" "$@"
	;;
*)
	warn "running" "$inchroot_path" "$@"
	exec "$inchroot_path" "$@"
	;;
esac