provide a bogus shell for the disabled accounts

src/etc/master.passwd

@@ -1,10 +1,9 @@
 root::0:0::0:0:Charlie &:/root:/bin/csh
-toor:*:0:0::0:0:Bourne-again Superuser:/root:
-daemon:*:1:31::0:0:The devil himself:/root:
-operator:*:2:20::0:0:System &:/usr/guest/operator:/bin/csh
+toor:*:0:0::0:0:Bourne-again Superuser:/root:/dev/null
+daemon:*:1:31::0:0:The devil himself:/root:/dev/null
+operator:*:2:20::0:0:System &:/usr/guest/operator:/dev/null
 bin:*:3:7::0:0:Binaries Commands and Source,,,:/:/dev/null
-games:*:7:13::0:0:Games pseudo-user:/usr/games:
+games:*:7:13::0:0:Games pseudo-user:/usr/games:/dev/null
 uucp:*:66:1::0:0:UNIX-to-UNIX Copy:/var/spool/uucppublic:/usr/libexec/uucp/uucico
 nobody:*:32767:9999::0:0:Unprivileged user:/nonexistent:/dev/null
-ingres:*:267:74::0:0:& Group:/usr/ingres:/bin/csh
-falken:*:32766:31::0:0:Prof. Stephen &:/usr/games:/usr/games/wargames
+ingres:*:267:74::0:0:& Group:/usr/ingres:/dev/null