eliminated old-style sed in favour of builtin regex matching;

--- a/lib/scripts/polyml-version	Mon Nov 15 17:14:43 2010 +0100
+++ b/lib/scripts/polyml-version	Mon Nov 15 17:39:23 2010 +0100
@@ -2,11 +2,17 @@
 #
 # polyml-version --- determine Poly/ML runtime system version
 
-echo -n polyml
-
 if [ -x "$ML_HOME/poly" ]; then
-  env LD_LIBRARY_PATH="$ML_HOME:$ML_HOME/../lib:$LD_LIBRARY_PATH" \
+  VERSION="$(env \
+    LD_LIBRARY_PATH="$ML_HOME:$ML_HOME/../lib:$LD_LIBRARY_PATH" \
     DYLD_LIBRARY_PATH="$ML_HOME:$ML_HOME/../lib:$DYLD_LIBRARY_PATH" \
-    "$ML_HOME/poly" -v -H 10 | \
-    sed -n 's,^Poly/ML.*RTS version: [^ ]*\(-[^ ]*\).*$,\1,p'
+    "$ML_HOME/poly" -v -H 10)"
+  REGEXP='^Poly/ML.*RTS version: [^ ]*(-[^ ]*).*$'
+  if [[ "$VERSION" =~ $REGEXP ]]; then
+    echo "polyml${BASH_REMATCH[1]}"
+  else
+    echo polyml-unknown
+  fi
+else
+  echo polyml-unknown
 fi