[patch] Patch adding the lib

0001-Add-a-module-to-manage-symlinks-like-bin-sh-usr-bin-.patch (text/plain), 6.72 KB, created by Michał Górny on 2013-01-10 10:55:57 UTC

From ee063f40a30fd0564ab0aaed0767a40cc7f2e8ae Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Micha=C5=82=20G=C3=B3rny?= <[e-mail]>
Date: Thu, 10 Jan 2013 11:52:53 +0100
Subject: [PATCH 1/2] Add a module to manage symlinks like /bin/sh,
 /usr/bin/pinentry...

---
 libs/Makefile.am         |   2 +
 libs/bin-symlink.bash.in | 218 +++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 220 insertions(+)
 create mode 100644 libs/bin-symlink.bash.in

diff --git a/libs/Makefile.am b/libs/Makefile.am
index bab373e..eefbeff 100644
--- a/libs/Makefile.am
+++ b/libs/Makefile.am
@@ -1,6 +1,7 @@
 eselectlibsdir = $(datadir)/$(PACKAGE_NAME)/libs/
 
 eselectlibs_DATA = \
+	bin-symlink.bash \
 	config.bash \
 	core.bash \
 	default.eselect \
@@ -14,6 +15,7 @@ eselectlibs_DATA = \
 	tests.bash
 
 EXTRA_DIST = \
+	bin-symlink.bash.in \
 	config.bash.in \
 	core.bash.in \
 	default.eselect.in \
diff --git a/libs/bin-symlink.bash.in b/libs/bin-symlink.bash.in
new file mode 100644
index 0000000..9332ba8
--- /dev/null
+++ b/libs/bin-symlink.bash.in
@@ -0,0 +1,218 @@
+# -*-eselect-*-  vim: ft=eselect
+# Copyright (c) 2005-2013 Gentoo Foundation
+#
+# This file is part of the 'eselect' tools framework.
+#
+# eselect 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 2 of the License, or (at your option) any later
+# version.
+#
+# eselect 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
+# eselect.  If not, see <http://www.gnu.org/licenses/>.
+
+# This library is for managing a common binary symlink like /bin/sh
+# or /usr/bin/pinentry. To use it, you need to set the following
+# variables:
+#
+# SYMLINK_PATH is the name of symlink being created, e.g. "/bin/sh".
+# The path should be absolute, without EPREFIX (it will be added).
+#
+# SYMLINK_TARGETS is the list (bash array) of targets being available.
+# The paths should be relative to ${SYMLINK_PATH}. Only basenames
+# of the targets will be displayed to user. Best (preferred) targets
+# should go earlier on the list.
+#
+# SYMLINK_DESCRIPTION is the human-friendly name of the symlink, e.g.
+# "POSIX shell". It will be used in the context of "implementation"
+# or "symlink". Defaults to basename of ${SYMLINK_PATH}.
+#
+# SYMLINK_CRUCIAL should be set to a non-null value if existence of no
+# targets should trigger a fatal error rather than silent symlink
+# removal.
+
+# Maintainer: [e-mail]
+# Based on the work of:
+# - Erik Hahn; bug #214817
+# - Samuli Suominen <[e-mail]>; eselect-pinentry
+
+## Global variables ##
+
+if [[ ! ${SYMLINK_PATH} ]]; then
+	die "SYMLINK_PATH needs to be set by eselect module."
+fi
+
+if [[ ! ${SYMLINK_TARGETS[@]} ]]; then
+	die "SYMLINK_TARGETS need to be set by eselect module."
+fi
+
+: ${SYMLINK_DESCRIPTION:-${SYMLINK_PATH##*/}}
+
+## Functions ##
+
+# find a list of symlink targets, best first
+find_targets() {
+	local basedir=${SYMLINK_PATH%/*}
+	TARGETS=()
+
+	local t
+	for t in "${SYMLINK_TARGETS[@]}"; do
+		if [[ -x ${EROOT}${basedir}/${t} ]]; then
+			TARGETS+=( ${t} )
+		fi
+	done
+}
+
+# set the pinentry symlink
+set_symlinks() {
+	local target="${1}" targets
+	local basedir=${SYMLINK_PATH%/*}
+
+	[[ ! -L ${EROOT}${SYMLINK_PATH} && -e ${EROOT}${SYMLINK_PATH} ]] && \
+		die -q "${EROOT}${SYMLINK_PATH} is not a symlink!"
+
+	if is_number "${target}" && [[ ${target} -ge 1 ]]; then
+		local TARGETS
+
+		find_targets
+		target=${TARGETS[target-1]}
+	elif [[ ! -x ${EROOT}${basedir}/${target} ]]; then
+		# try basename matching
+		local TARGETS t
+		find_targets
+
+		for t in "${TARGETS[@]}"; do
+			if [[ ${t##*/} == ${target} ]]; then
+				target=${t}
+				break
+			fi
+		done
+	fi
+
+	if [[ -x ${EROOT}${basedir}/${target} ]]; then
+		local tmpf=${EROOT}${SYMLINK_PATH}.new
+		# we could use 'ln -f' to directly replace the symlink
+		# but 'mv' is an atomic operation so it should be more fault-proof
+
+		ln -s "${target}" "${tmpf}" || \
+			die -q "Unable to create temporary symlink"
+		if ! mv "${tmpf}" "${EROOT}${SYMLINK_PATH}"; then
+			rm -f "${tmpf}" # cleanup
+			die -q "Unable to replace ${EROOT}${SYMLINK_PATH} symlink with ${target}"
+		fi
+	else
+		die -q "Target '${target}' doesn't appear to be valid!"
+	fi
+}
+
+### show action ###
+
+describe_show() {
+	echo "Show the current ${SYMLINK_DESCRIPTION} implementation"
+}
+
+do_show() {
+	[[ ${@} ]] && die -q "Too many parameters"
+
+	write_list_start "Current ${SYMLINK_DESCRIPTION} implementation:"
+	if [[ -L ${EROOT}${SYMLINK_PATH} ]]; then
+		local t=$(readlink "${EROOT}${SYMLINK_PATH}")
+		write_kv_list_entry "${t##*/}" ""
+	elif [[ -e ${EROOT}${SYMLINK_PATH} ]]; then
+		write_kv_list_entry "(not a symlink)" ""
+	else
+		write_kv_list_entry "(unset)" ""
+	fi
+}
+
+### list action ###
+
+describe_list() {
+	echo "List available ${SYMLINK_DESCRIPTION} implementations"
+}
+
+do_list() {
+	[[ ${@} ]] && die -q "Too many parameters"
+
+	local i TARGETS
+	find_targets
+
+	write_list_start "Available ${SYMLINK_DESCRIPTION} implementations:"
+	if [[ ${TARGETS[@]} ]]; then
+		local curr=$(readlink "${EROOT}${SYMLINK_PATH}")
+
+		for (( i = 0; i < ${#TARGETS[@]}; i++ )) ; do
+			[[ ${TARGETS[${i}]##*/} == ${curr##*/} ]] && \
+				TARGETS[${i}]+=" $(highlight '*')"
+		done
+		write_numbered_list "${TARGETS[@]##*/}"
+	else
+		write_kv_list_entry "(none found)" ""
+	fi
+}
+
+### set action ###
+
+describe_set() {
+	echo "Set a new ${SYMLINK_DESCRIPTION} implementation"
+}
+
+describe_set_options() {
+	echo "target : Target name, number (from 'list' action) or path"
+}
+
+describe_set_parameters() {
+	echo "<target>"
+}
+
+do_set() {
+	if [[ ${#} != 1 ]]; then
+		die -q "set takes exactly one parameter"
+	else
+		set_symlinks "${1}"
+	fi
+}
+
+### update action ###
+
+describe_update() {
+	echo "Automatically update the ${SYMLINK_DESCRIPTION} implementation"
+}
+
+describe_update_options() {
+	echo "--if-unset : do not override existing implementation"
+}
+
+do_update() {
+	[[ ${1} == ifunset ]] && set -- --if-unset "${@:2}"
+
+	if [[ ( ${1} && ${1} != '--if-unset' ) || ${2} ]]
+	then
+		die -q "usage error"
+	fi
+
+	if [[ ${1} == '--if-unset' && -L ${EROOT}${SYMLINK_PATH} \
+			&& -x ${EROOT}${SYMLINK_PATH} ]]
+	then
+		return
+	fi
+
+	local TARGETS
+	find_targets
+
+	if [[ ! ${TARGETS[@]} ]]; then
+		if [[ ${SYMLINK_CRUCIAL} ]]; then
+			die "No targets for ${EROOT}${SYMLINK_PATH}, system likely broken."
+		else
+			rm -f "${EROOT}${SYMLINK_PATH}"
+		fi
+	fi
+
+	set_symlinks "${TARGETS[0]}"
+}
+
+# vim:ts=4:sts=4:sw=4
-- 
1.8.1