Implementation of working alternatives on pacman

build-package.sh

@@ -30,6 +30,9 @@ source "$TERMUX_SCRIPTDIR/scripts/utils/docker/docker.sh"; docker__create_docker
 # Source the `termux_package` library.
 source "$TERMUX_SCRIPTDIR/scripts/utils/termux/package/termux_package.sh"
 
+# Source the `termux_alternatives` library.
+source "$TERMUX_SCRIPTDIR/scripts/utils/termux/alternatives/termux_alternatives.sh"
+
 export SOURCE_DATE_EPOCH=${SOURCE_DATE_EPOCH:-$(git -c log.showSignature=false log -1 --pretty=%ct 2>/dev/null || date "+%s")}
 
 if [ "$(uname -o)" = "Android" ] || [ -e "/system/bin/app_process" ]; then
@@ -331,6 +334,10 @@ termux_step_post_make_install() {
 # shellcheck source=scripts/build/termux_step_install_pacman_hooks.sh
 source "$TERMUX_SCRIPTDIR/scripts/build/termux_step_install_pacman_hooks.sh"
 
+# Install switcher files that will provide alternatives for pacman package
+# shellcheck source=scripts/build/termux_step_install_switcher_files.sh
+source "$TERMUX_SCRIPTDIR/scripts/build/termux_step_install_switcher_files.sh"
+
 # Add service scripts from array TERMUX_PKG_SERVICE_SCRIPT, if it is set
 # shellcheck source=scripts/build/termux_step_install_service_scripts.sh
 source "$TERMUX_SCRIPTDIR/scripts/build/termux_step_install_service_scripts.sh"
@@ -751,7 +758,10 @@ for ((i=0; i<${#PACKAGE_LIST[@]}; i++)); do
 		termux_run_base_and_multilib_build_step termux_step_make_install
 		cd "$TERMUX_PKG_BUILDDIR"
 		termux_step_post_make_install
-		termux_step_install_pacman_hooks
+		if [ "$TERMUX_PACKAGE_FORMAT" = "pacman" ]; then
+			termux_step_install_pacman_hooks
+			termux_step_install_switcher_files
+		fi
 		termux_step_install_service_scripts
 		termux_step_install_license
 		cd "$TERMUX_PKG_MASSAGEDIR"

packages/pacman/build.sh

@@ -3,9 +3,11 @@ TERMUX_PKG_DESCRIPTION="A library-based package manager with dependency support"
 TERMUX_PKG_LICENSE="GPL-2.0"
 TERMUX_PKG_MAINTAINER="@Maxython <[email protected]>"
 TERMUX_PKG_VERSION=7.0.0
-TERMUX_PKG_REVISION=4
-TERMUX_PKG_SRCURL=https://gitlab.archlinux.org/pacman/pacman/-/releases/v${TERMUX_PKG_VERSION}/downloads/pacman-${TERMUX_PKG_VERSION}.tar.xz
-TERMUX_PKG_SHA256=61cbd445d1381b4b184bc7c4e2791f07a79f0f2807b7c600399d0d08e8cd28cf
+TERMUX_PKG_REVISION=5
+TERMUX_PKG_SRCURL=(https://gitlab.archlinux.org/pacman/pacman/-/releases/v${TERMUX_PKG_VERSION}/downloads/pacman-${TERMUX_PKG_VERSION}.tar.xz
+		https://github.com/termux-pacman/pacman-switch/archive/refs/heads/main.zip)
+TERMUX_PKG_SHA256=(61cbd445d1381b4b184bc7c4e2791f07a79f0f2807b7c600399d0d08e8cd28cf
+		786056cd99fb2517c30e13db1834e7d16ed4650bfeb428e39b7acfd85d4abce9)
 TERMUX_PKG_DEPENDS="bash, curl, gpgme, libandroid-glob, libarchive, libcurl, openssl, termux-licenses, termux-keyring"
 TERMUX_PKG_BUILD_DEPENDS="doxygen, asciidoc, nettle"
 TERMUX_PKG_GROUPS="base-devel"
@@ -25,6 +27,7 @@ termux_step_pre_configure() {
 	rm -f ./scripts/libmakepkg/executable/fakeroot.sh.in
 
 	sed -i "s/@TERMUX_ARCH@/${TERMUX_ARCH}/" ./etc/{pacman,makepkg}.conf.in
+	sed -i "s|_ps_prefix=.*|_ps_prefix=\"${TERMUX_PREFIX}\"|" ./pacman-switch-main/pacman-switch.sh
 }
 
 termux_step_post_configure() {
@@ -34,12 +37,11 @@ termux_step_post_configure() {
 termux_step_post_make_install() {
 	mkdir -p $TERMUX_PREFIX/etc/pacman.d
 	install -m644 $TERMUX_PKG_BUILDER_DIR/serverlist $TERMUX_PREFIX/etc/pacman.d/serverlist
-}
+	install -m755 $TERMUX_PKG_SRCDIR/pacman-switch-main/pacman-switch.sh $TERMUX_PREFIX/bin/pacman-switch
 
-termux_step_create_debscripts() {
-	echo "#!$TERMUX_PREFIX/bin/bash" > postinst
-	echo "mkdir -p $TERMUX_PREFIX/var/lib/pacman/sync" >> postinst
-	echo "mkdir -p $TERMUX_PREFIX/var/lib/pacman/local" >> postinst
-	echo "mkdir -p $TERMUX_PREFIX/var/cache/pacman/pkg" >> postinst
-	chmod 755 postinst
+	for dir in var/lib/pacman/{sync,local,switch} var/cache/pacman/pkg share/pacman-switch; do
+		dir="${TERMUX_PREFIX}/${dir}"
+		mkdir -p ${dir}
+		touch ${dir}/.placeholder
+	done
 }

packages/pacman/pacman-switch-disable.alpm.hook

@@ -0,0 +1,10 @@
+[Trigger]
+Type = Path
+Operation = Remove
+Target = @TERMUX_PREFIX_TARGET@/share/pacman-switch/*.sw
+
+[Action]
+Description = Automatic disabling switchers...
+When = PreTransaction
+Exec = @TERMUX_PREFIX@/share/libalpm/scripts/run-pacman-switch disable
+NeedsTargets

packages/pacman/pacman-switch-enable.alpm.hook

@@ -0,0 +1,10 @@
+[Trigger]
+Type = Path
+Operation = Install
+Target = @TERMUX_PREFIX_TARGET@/share/pacman-switch/*.sw
+
+[Action]
+Description = Automatic enabling switchers...
+When = PostTransaction
+Exec = @TERMUX_PREFIX@/share/libalpm/scripts/run-pacman-switch enable
+NeedsTargets

packages/pacman/pacman-switch-update.alpm.hook

@@ -0,0 +1,10 @@
+[Trigger]
+Type = Path
+Operation = Upgrade
+Target = @TERMUX_PREFIX_TARGET@/share/pacman-switch/*.sw
+
+[Action]
+Description = Automatic updating switchers...
+When = PostTransaction
+Exec = @TERMUX_PREFIX@/share/libalpm/scripts/run-pacman-switch update
+NeedsTargets

packages/pacman/run-pacman-switch.alpm.script

@@ -0,0 +1,27 @@
+#!@TERMUX_PREFIX@/bin/bash
+
+set -e
+
+sws=()
+export _PS_RUN_IN_ALPM_HOOKS=true
+
+while read -r i; do
+	sw="$(basename "${i//.sw/}")"
+	if [[ -n "${sw}" && "${sw}" != "*" ]]; then
+		sws+=("${sw}")
+	fi
+done
+
+if [[ -n "${sws}" && ("${1}" = "update" || "${1}" = "disable") ]]; then
+	sws=($(pacman-switch -Qs ${sws[@]}))
+fi
+
+if [ -z "${sws}" ]; then
+	exit 0
+fi
+
+case "${1}" in
+	"enable") pacman-switch -Ea ${sws[@]};;
+	"update") pacman-switch -Su ${sws[@]};;
+	"disable") pacman-switch -Da ${sws[@]};;
+esac

scripts/build/termux_step_create_pacman_package.sh

@@ -122,9 +122,6 @@ termux_step_create_pacman_package() {
 
 	# Write installation hooks.
 	termux_step_create_debscripts
-	# Process `update-alternatives` entries from `.alternatives` files
-	# These need to be merged into the `.postinst` and `.prerm` files, so after those are created.
-	termux_step_update_alternatives
 	termux_step_create_pacman_install_hook
 
 	# ensure all elements of the package have the same mtime

scripts/build/termux_step_install_pacman_hooks.sh

@@ -1,7 +1,5 @@
 termux_step_install_pacman_hooks() {
-	[[ "$TERMUX_PACKAGE_FORMAT" != "pacman" ]] && return
-
-	local sed="sed -e s|@TERMUX_PREFIX@|${TERMUX_PREFIX}|g -e s|@TERMUX_PREFIX_TARGET@|${TERMUX_PREFIX:1}|g -e s|@TERMUX_ARCH@|${TERMUX_ARCH}|g"
+	local sed="sed -e s|@TERMUX_PREFIX@|${TERMUX_PREFIX_CLASSICAL}|g -e s|@TERMUX_PREFIX_TARGET@|${TERMUX_PREFIX_CLASSICAL:1}|g -e s|@TERMUX_ARCH@|${TERMUX_ARCH}|g"
 
 	# Installing hooks
 	local hooks
@@ -10,7 +8,7 @@ termux_step_install_pacman_hooks() {
 		mkdir -p ${TERMUX_PREFIX}/share/libalpm/hooks
 		local hook
 		for hook in ${hooks}; do
-			${sed} "${hook}" > "${TERMUX_PREFIX}/share/libalpm/hooks/$(sed 's|.alpm.hook$|.hook|' <<< "${hook##*/}")"
+			${sed} "${hook}" > "${TERMUX_PREFIX_CLASSICAL}/share/libalpm/hooks/$(sed 's|.alpm.hook$|.hook|' <<< "${hook##*/}")"
 		done
 	fi
 
@@ -21,7 +19,7 @@ termux_step_install_pacman_hooks() {
 		mkdir -p ${TERMUX_PREFIX}/share/libalpm/scripts
 		local script script_alpm
 		for script in ${scripts}; do
-			script_alpm="${TERMUX_PREFIX}/share/libalpm/scripts/$(sed 's|.alpm.script$||' <<< "${script##*/}")"
+			script_alpm="${TERMUX_PREFIX_CLASSICAL}/share/libalpm/scripts/$(sed 's|.alpm.script$||' <<< "${script##*/}")"
 			${sed} "${script}" > "${script_alpm}"
 			chmod +x "${script_alpm}"
 		done

scripts/build/termux_step_install_switcher_files.sh

@@ -0,0 +1,20 @@
+termux_step_install_switcher_files() {
+	local i
+	for i in "${TERMUX_PKG_BUILDER_DIR}"/*.alternatives; do
+		[[ -f "${i}" ]] || continue
+		local -a NAME=()
+		local -A DEPENDENTS=() LINK=() ALTERNATIVE=() PRIORITY=()
+		termux_alternatives__parse_alternatives_file "${i}"
+
+		mkdir -p "${TERMUX_PREFIX_CLASSICAL}/share/pacman-switch"
+		{
+			local name
+			for name in "${NAME[@]}"; do
+				echo "switcher_group_${name}() {"
+				echo "  priority=${PRIORITY[$name]}"
+				echo "  associations=(${LINK[$name]}:${ALTERNATIVE[$name]}${DEPENDENTS[$name]})"
+				echo "}"
+			done
+		} > "${TERMUX_PREFIX_CLASSICAL}/share/pacman-switch/$(basename "${i//.alternatives/.sw}")"
+	done
+}

scripts/build/termux_step_update_alternatives.sh

@@ -1,57 +1,24 @@
 # shellcheck shell=bash
 
-# The Debian `.alternatives` format is a simple ad-hoc plain text format
-# to declaratively define groups for `update-alternatives`.
-# This function parses files of this format and returns their contents
-# in the associative arrays: ${LINK[@]} ${[ALTERNATIVE@]} ${DEPENDENTS[@]} ${PRIORITY[@]}
-termux_parse_alternatives() {
-	local line key value
-	local dependents=0
-	while IFS=$'\n' read -r line; do
-
-		key="${line%%:*}" # Part before the first ':'
-		value="${line#*:[[:blank:]]*}" # Part after the first `:`, leading whitespace stripped
-
-		case "$key" in
-			'Name') NAME+=("$value") dependents=0 ;;
-			'Link')               LINK[${NAME[-1]}]="$value" dependents=0 ;;
-			'Alternative') ALTERNATIVE[${NAME[-1]}]="$value" dependents=0 ;;
-			'Priority')       PRIORITY[${NAME[-1]}]="$value" dependents=0 ;;
-			'Dependents') dependents=1; continue;;
-		esac
-
-		if (( dependents )); then
-			read -r dep_link dep_name dep_alternative <<< "$line"
-			DEPENDENTS[${NAME[-1]}]+="      --slave \"${TERMUX_PREFIX}/${dep_link}\" \"${dep_name}\" \"${TERMUX_PREFIX}/${dep_alternative}\""$' \\\n'
-		fi
-
-	done < <(sed -e 's|\s*#.*$||g' "$1") # Strip out any comments
-}
-
 termux_step_update_alternatives() {
 	printf '%s\n' "INFO: Processing 'update-alternatives' entries:" 1>&2
 	for alternatives_file in "${TERMUX_PKG_BUILDER_DIR}"/*.alternatives; do
 		[[ -f "$alternatives_file" ]] || continue
 		local -a NAME=()
 		local -A DEPENDENTS=() LINK=() ALTERNATIVE=() PRIORITY=()
-		termux_parse_alternatives "$alternatives_file"
+		termux_alternatives__parse_alternatives_file "$alternatives_file"
 
 		# Handle postinst script
 		[[ -f postinst ]] && mv postinst{,.orig}
 
 		local name
-		for name in "${NAME[@]}"; do
-			# Not every entry will have dependents in its group
-			# but we need to initialize the keys regardless
-			: "${DEPENDENTS[$name]:=}"
-		done
 
 		{ # Splice in the alternatives
 		# Use the original shebang if there's a 'postinst.orig'
 		[[ -f postinst.orig ]] && head -n1 postinst.orig || echo "#!${TERMUX_PREFIX}/bin/sh"
 		# Boilerplate header comment and checks
 		echo "# Automatically added by termux_step_update_alternatives"
-		echo "if [ \"\$1\" = 'configure' ] || [ \"\$1\" = 'abort-upgrade' ] || [ \"\$1\" = 'abort-deconfigure' ] || [ \"\$1\" = 'abort-remove' ] || [ \"${TERMUX_PACKAGE_FORMAT}\" = 'pacman' ]; then"
+		echo "if [ \"\$1\" = 'configure' ] || [ \"\$1\" = 'abort-upgrade' ] || [ \"\$1\" = 'abort-deconfigure' ] || [ \"\$1\" = 'abort-remove' ]; then"
 		echo "  if [ -x \"${TERMUX_PREFIX}/bin/update-alternatives\" ]; then"
 		# 'update-alternatives' command for each group
 		for name in "${NAME[@]}"; do
@@ -86,7 +53,7 @@ termux_step_update_alternatives() {
 		[[ -f prerm.orig ]] && head -n1 prerm.orig || echo "#!${TERMUX_PREFIX}/bin/sh"
 		# Boilerplate header comment and checks
 		echo "# Automatically added by termux_step_update_alternatives"
-		echo "if [ \"\$1\" = 'remove' ] || [ \"\$1\" != 'upgrade' ] || [ \"${TERMUX_PACKAGE_FORMAT}\" = 'pacman' ]; then"
+		echo "if [ \"\$1\" = 'remove' ] || [ \"\$1\" != 'upgrade' ]; then"
 		echo "  if [ -x \"${TERMUX_PREFIX}/bin/update-alternatives\" ]; then"
 		# Remove each group
 		for name in "${NAME[@]}"; do

scripts/utils/termux/alternatives/termux_alternatives.sh

@@ -0,0 +1,56 @@
+# shellcheck shell=bash
+
+# Title:          termux_alternatives
+# Description:    A library for working with Termux package Alternatives.
+
+
+
+##
+# Parse datas from the alternatives file and put the datas into the variables.
+# .
+# .
+# **Parameters:**
+# `path_to_alternatives_file` - The path to the package's `.alternatives` file.
+# .
+# **Returns:**
+# returns their contents in the associative arrays:
+# ${LINK[@]} ${[ALTERNATIVE[@]} ${DEPENDENTS[@]} ${PRIORITY[@]}
+# .
+# .
+# termux_alternatives__parse_alternatives_file <path_to_alternatives_file>
+##
+termux_alternatives__parse_alternatives_file() {
+	local line key value
+	local dependents=0
+	while IFS=$'\n' read -r line; do
+
+		key="${line%%:*}" # Part before the first ':'
+		value="${line#*:[[:blank:]]*}" # Part after the first `:`, leading whitespace stripped
+
+		case "$key" in
+			'Name') NAME+=("$value") dependents=0 ;;
+			'Link')               LINK[${NAME[-1]}]="$value" dependents=0 ;;
+			'Alternative') ALTERNATIVE[${NAME[-1]}]="$value" dependents=0 ;;
+			'Priority')       PRIORITY[${NAME[-1]}]="$value" dependents=0 ;;
+			'Dependents') dependents=1; continue;;
+		esac
+
+		if (( dependents )); then
+			read -r dep_link dep_name dep_alternative <<< "$line"
+			if [ "${TERMUX_PACKAGE_FORMAT}" = "pacman" ]; then
+				# Data format for pacman-switch
+				DEPENDENTS[${NAME[-1]}]+=" ${dep_link}:${dep_alternative}"
+			else
+				# Data format for update-alternatives
+				DEPENDENTS[${NAME[-1]}]+="      --slave \"${TERMUX_PREFIX_CLASSICAL}/${dep_link}\" \"${dep_name}\" \"${TERMUX_PREFIX_CLASSICAL}/${dep_alternative}\""$' \\\n'
+			fi
+		fi
+
+	done < <(sed -e 's|\s*#.*$||g' "$1") # Strip out any comments
+
+	for key in "${NAME[@]}"; do
+		# Not every entry will have dependents in its group
+		# but we need to initialize the keys regardless
+		: "${DEPENDENTS[$key]:=}"
+	done
+}