Index: /server/common/oursrc/accountadm/signup-scripts-backend.in
===================================================================
--- /server/common/oursrc/accountadm/signup-scripts-backend.in	(revision 487)
+++ /server/common/oursrc/accountadm/signup-scripts-backend.in	(revision 488)
@@ -28,5 +28,12 @@
 complain("bad username") unless($username =~ /^[\w._-]+$/);
 
-complain("banned username") if(`@grep_path@ '$username' /afs/athena.mit.edu/contrib/scripts/admin/users.banned` != "");
+open(BANNEDUSERS,
+        "</afs/athena.mit.edu/contrib/scripts/admin/users.banned");
+while (<BANNEDUSERS>) {
+    chomp;
+    if ($_ eq $username)
+        complain("banned username");
+}
+close(BANNEDUSERS);
 
 my $homedir;