feat: add loongarch64-it.bash

Not going to need this for long, thankfully.

Author: MingcongBai

loong64-it/loongarch64-it.bash

@@ -0,0 +1,106 @@
+#!/bin/bash
+# A simple loong64 => loongarch64 .deb converter to help traverse the worlds.
+#
+# Mingcong Bai <[email protected]>, 2024
+
+_display_usage() {
+	printf "\
+Usage:
+
+	loong64-it [PACKAGE1] [PACKAGE2] ...
+
+        - PACKAGE{1..N}: Path to the new-world .deb package to convert.
+
+"
+}
+
+# Autobuild-like echo functions.
+abwarn() { echo -e "[\e[33mWARN\e[0m]:  \e[1m$*\e[0m"; }
+aberr()  { echo -e "[\e[31mERROR\e[0m]: \e[1m$*\e[0m"; exit 1; }
+abinfo() { echo -e "[\e[96mINFO\e[0m]:  \e[1m$*\e[0m"; }
+abdbg()  { echo -e "[\e[32mDEBUG\e[0m]: \e[1m$*\e[0m"; }
+
+_convert_loong64() {
+	abinfo "Examining package information: $1 ..."
+	dpkg -I "$SRCDIR"/$1 || \
+		aberr "Invalid dpkg package: control (metadata) archive not found: $?"
+	CONTROL_EXT="$(ar t "$SRCDIR"/$1 | grep control.tar* | cut -f3 -d'.')"
+	case "${CONTROL_EXT}" in
+		gz)
+			TAR_COMP_FLAG="z"
+			;;
+		xz)
+			TAR_COMP_FLAG="J"
+			;;
+		bz2)
+			TAR_COMP_FLAG="j"
+			;;
+		"")
+			TAR_COMP_FLAG=""
+			;;
+		*)
+			aberr "Invalid control archive extension ${CONTROL_EXT}!"
+			;;
+	esac
+
+	abinfo "Unpacking: $1 ..."
+	cd $(mktemp -d) || \
+		aberr "Failed to create temporary directory to unpack $1: $?."
+	DEBDIR="$(pwd)"
+	ar xv "$SRCDIR"/$1 || \
+		aberr "Failed to unpack $1: $?."
+
+	abinfo "Unpacking metadata archive: $1 ..."
+	mkdir "$DEBDIR"/metadata || \
+		aberr "Failed to create temporary directory for extracting the metdata archive from $1: $?."
+	tar -C "$DEBDIR"/metadata -xvf control.tar."${CONTROL_EXT}" || \
+		aberr "Failed to unpack metadata archive from $1: $?."
+
+	abinfo "Converting dpkg Architecture key: $1 ..."
+	if ! egrep '^Architecture: loong64$' "$DEBDIR"/metadata/control; then
+		aberr "Failed to detect a \"loong64\" architecture signature in control file - this is not a valid new-world LoongArch package!"
+	fi
+	sed -e 's|^Architecture: loong64$|Architecture: loongarch64|g' \
+	    -i "$DEBDIR"/metadata/control
+
+	abinfo "Building metadata archive (control.tar.${CONTROL_EXT}): $1 ..."
+	cd "$DEBDIR"/metadata
+	tar cvf${TAR_COMP_FLAG} "$DEBDIR"/control.tar."${CONTROL_EXT}" * || \
+		aberr "Failed to build metadata archive (control.tar.${CONTROL_EXT}) for $1: $?."
+	cd "$DEBDIR"
+
+	abinfo "Rebuilding dpkg package $1: loongarch64 ..."
+	ar rv "$SRCDIR"/$1 control.tar.${CONTROL_EXT} || \
+		aberr "Failed to rebuild dpkg package $1: $?."
+
+        #abinfo "Cleaning up: $1 ..."
+        #rm -r "$DEBDIR"
+
+	abinfo """Your requested package:
+
+    $1
+
+Has been successfully converted as a loongarch64 package!
+"""
+}
+
+# Display usage info if `-h' or `--help' is specified.
+if [[ "$1" == "-h" || "$1" == "--help" ]]; then
+	_display_usage
+	exit 0
+fi
+
+# Display usage info with directions if no option is specified.
+if [ -z "$1" ]; then
+	abwarn "Please specify package(s) to convert.\n"
+	_display_usage
+	exit 1
+fi
+
+# Record working directory.
+SRCDIR="$(pwd)"
+
+# Rebuilding all requested packages.
+for i in "$@"; do
+	_convert_loong64 $i
+done