system/cabextract: miscellaneous cleanups

Signed-off-by: Robby Workman <rworkman@slackbuilds.org>

system/cabextract/cabextract.SlackBuild

@@ -24,28 +24,37 @@
 
 PRGNAM=cabextract
 VERSION=1.2
-ARCH=${ARCH:-i486}
 BUILD=${BUILD:-1}
 TAG=${TAG:-_SBo}
 
+# Automatically determine the architecture we're building on:
+if [ -z "$ARCH" ]; then
+  case "$( uname -m )" in
+    i?86) ARCH=i486 ;;
+    arm*) ARCH=arm ;;
+    # Unless $ARCH is already set, use uname -m for all other archs:
+       *) ARCH=$( uname -m ) ;;
+  esac
+fi
+
 CWD=$(pwd)
 TMP=${TMP:-/tmp/SBo}
 PKG=$TMP/package-$PRGNAM
 OUTPUT=${OUTPUT:-/tmp}
 
-case "$ARCH" in
-  i486)      SLKCFLAGS="-O2 -march=i486 -mtune=i686"
-             ;;
-  i686)      SLKCFLAGS="-O2 -march=i686 -mtune=i686"
-             ;;
-  s390)      SLKCFLAGS="-O2"
-             ;;
-  powerpc)   SLKCFLAGS="-O2"
-             ;;
-  x86_64)    SLKCFLAGS="-O2 -fPIC"
-             SLKLDFLAGS="-L/usr/lib64"; LIBDIRSUFFIX="64"
-             ;;
-esac
+if [ "$ARCH" = "i486" ]; then
+  SLKCFLAGS="-O2 -march=i486 -mtune=i686"
+  LIBDIRSUFFIX=""
+elif [ "$ARCH" = "i686" ]; then
+  SLKCFLAGS="-O2 -march=i686 -mtune=i686"
+  LIBDIRSUFFIX=""
+elif [ "$ARCH" = "x86_64" ]; then
+  SLKCFLAGS="-O2 -fPIC"
+  LIBDIRSUFFIX="64"
+else
+  SLKCFLAGS="-O2"
+  LIBDIRSUFFIX=""
+fi
 
 set -e