automagically choose correct preload library on biarch systems

Uses "file" to check whether called program is a 32bit or 64bit ELF
file. If that cannot be determined it checks the uname.

Signed-off-by: Ludwig Nussel <ludwig.nussel@suse.de>

Index: mumble-1.1.3/scripts/mumble-overlay
===================================================================
--- mumble-1.1.3.orig/scripts/mumble-overlay
+++ mumble-1.1.3/scripts/mumble-overlay
@@ -1,9 +1,47 @@
-#! /bin/sh
+#!/bin/bash
 
-if [ -d /usr/lib/mumble ]; then
-  MUMBLE_OVERLAY_PATH=/usr/lib/mumble
+libdir=/usr/lib
+if [ -z "$1" -o "$1" = '--help' ]; then
+	echo "USAGE: $0 <program> [args...]"
+	exit 1
+fi
+
+# biarch system?
+if [ -d /usr/lib64 ]; then
+	binary="$1"
+        # no slashes? search in $PATH
+	if [ "${binary/\/}" = "$binary" ]; then
+		found=
+		for i in ${PATH//:/ }; do
+			if [ -x "$i/$binary" ]; then
+				found="$i/$binary"
+				break
+			fi
+		done
+		binary="$found"
+	fi
+	if [ -z "$binary" ]; then
+		echo "$1 not found" >&2
+		exit 1
+	fi
+	case `file "$binary"` in
+		*64-bit*) libdir=/usr/lib64 ;;
+		*32-bit*) ;;
+		*)
+			# target is no ELF binary, fall back to machine
+			# architecture. User has to use e.g. linux32 or
+			# setarch to change to 32bit on 64bit archs then
+			case "`uname -m`" in
+				x86_64|s390x|ppc64) libdir=/usr/lib64 ;;
+			esac
+			;;
+	esac
+fi
+
+if [ -d $libdir/mumble ]; then
+  MUMBLE_OVERLAY_PATH=$libdir/mumble
 else
-  MUMBLE_OVERLAY_PATH=/usr/lib
+  MUMBLE_OVERLAY_PATH=$libdir
 fi
 
 if [ -f /etc/sysconfig/mumble ]; then