From d456d570f035ee206503da8a98ee3fd7d3ec3f02 Mon Sep 17 00:00:00 2001
From: Martin Matous <m@matous.dev>
Date: Wed, 30 Mar 2022 22:18:25 +0200
Subject: [PATCH] initial commit

Signed-off-by: Martin Matous <m@matous.dev>
---
 ld.eselect | 108 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 108 insertions(+)
 create mode 100644 ld.eselect

diff --git a/ld.eselect b/ld.eselect
new file mode 100644
index 0000000..1f4fefb
--- /dev/null
+++ b/ld.eselect
@@ -0,0 +1,108 @@
+# Copyright (C) 2022 Martin Matouš
+
+# This program 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.
+
+# This program 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 this program. If not, see <http://www.gnu.org/licenses/>.
+
+DESCRIPTION="Manage linker symlink"
+MAINTAINER="Martin Matouš <m@matous.dev>"
+VERSION="1.0.0"
+
+BIN_DIR="${EROOT%/}/usr/bin"
+
+find_targets() {
+	local linker
+	# get all ld.* files
+	for linker in "${BIN_DIR}/"ld.*; do
+		[[ -f ${linker} ]] && basename "${linker}"
+	done
+}
+
+remove_symlink() {
+	[[ ! -e "${BIN_DIR}/ld" ]] && return
+	[[ -L "${BIN_DIR}/ld" ]] || die -q "${BIN_DIR}/ld is not a symlink!"
+	rm -f "${BIN_DIR}/ld"
+}
+
+set_symlink() {
+	local target="$1"
+	if is_number "${target}"; then
+		local -r targets=( $(find_targets) )
+		[[ ${target} -ge 1 && ${target} -le ${#targets[@]} ]] \
+			|| die -q "Number out of range: $1"
+		target=${targets[target-1]}
+	elif [[ ! "$target" == "ld."* ]]; then
+		target="ld.$target"
+	fi
+
+	if [[ ! -L "${BIN_DIR}/${target}" ]]; then
+		die -q "Target \"${1}\" (${BIN_DIR}/${target}) doesn't appear to be valid!"
+	fi
+
+	remove_symlink || die -q "Couldn't remove existing symlink"
+	ln -s "${target}" "${BIN_DIR}/ld"
+}
+
+### show action ###
+
+describe_show() {
+	echo "Show the current linker symlink"
+}
+
+do_show() {
+	write_list_start "Current linker symlink:"
+	if [[ -L "${BIN_DIR}/ld" ]]; then
+		# "dereference" only 1 layer od symlinking, unlike readlink/canonicalize
+		local -r linker=$(find "${BIN_DIR}/ld" -printf %l)
+		write_kv_list_entry "${linker}" ""
+	else
+		write_kv_list_entry "(unset)" ""
+	fi
+}
+
+### list action ###
+
+describe_list() {
+	echo "List available linkers"
+}
+
+do_list() {
+	local i
+	local targets=( $(find_targets) )
+
+	write_list_start "Available linker symlink targets:"
+	for (( i = 0; i < ${#targets[@]}; i++ )); do
+		[[ ${targets[i]} = $(find "${BIN_DIR}/ld" -printf %l) ]] \
+			&& targets[i]=$(highlight_marker "${targets[i]}")
+	done
+	write_numbered_list -m "(none found)" "${targets[@]}"
+}
+
+### set action ###
+
+describe_set() {
+	echo "Set a new linker symlink target"
+}
+
+describe_set_parameters() {
+	echo "<target>"
+}
+
+describe_set_options() {
+	echo "target : Target name or number (from 'list' action)"
+}
+
+do_set() {
+	local -r linker="$1"
+	[[ -z "$linker" ]] && die -q "You didn't tell me what to set the symlink to"
+	[[ $# -gt 1 ]] && die -q "Too many parameters"
+	set_symlink "$linker" || die -q "Couldn't set a new symlink"
+}