Check for bad result from pg_id. A bad result can come from shared library

trouble, and the name of the shared library has been changed recently.
 Had to rerun ldconfig on my machine to get it working again.
Give an error message with a helpful hint if so...

src/bin/initdb/initdb.sh

@@ -26,7 +26,7 @@
 #
 #
 # IDENTIFICATION
-#    $Header: /cvsroot/pgsql/src/bin/initdb/Attic/initdb.sh,v 1.45 1998/08/01 22:57:41 momjian Exp $
+#    $Header: /cvsroot/pgsql/src/bin/initdb/Attic/initdb.sh,v 1.46 1998/08/14 16:05:51 thomas Exp $
 #
 #-------------------------------------------------------------------------
 
@@ -240,6 +240,14 @@ fi
 
 POSTGRES_SUPERUID=`pg_id $POSTGRES_SUPERUSERNAME`
 
+if [ ${POSTGRES_SUPERUID:=-1} -eq -1 ]; then
+    echo "Unable to determine a valid username.  If you are running"
+    echo "initdb without an explicit username specified, then there"
+    echo "may be a problem with finding the Postgres shared library"
+    echo "and/or the pg_id utility."
+    exit 10
+fi
+
 if [ $POSTGRES_SUPERUID = NOUSER ]; then
     echo "Valid username not given.  You must specify the username for "
     echo "the Postgres superuser for the database system you are "
@@ -274,7 +282,7 @@ if [ -f "$PGDATA/PG_VERSION" ]; then
         echo "database system already exists."
         echo 
         echo "If you want to create a new database system, either remove "
-        echo "the $PGDATA directory or run initdb with a --pgdata option "
+        echo "the directory $PGDATA or run initdb with a --pgdata option "
         echo "other than $PGDATA."
         exit 1
     fi