--- loncom/lcuserdel	2000/10/29 22:07:20	1.7
+++ loncom/lcuserdel	2000/10/30 03:37:51	1.12
@@ -15,7 +15,6 @@ use strict;
 # /etc/passwd, /etc/groups, and /etc/smbpasswd.
 # It also disables user directory access by making the directory
 # to be owned by user=www (as opposed to the former "username").
-# It also removes group membership from www (via the groupdel command).
 # This command only returns an error if it is
 # invoked incorrectly (by passing bad command-line arguments, etc).
 
@@ -26,6 +25,11 @@ use strict;
 # Standard input usage
 # First line is USERNAME
 
+# Valid user names must consist of ascii
+# characters that are alphabetical characters
+# (A-Z,a-z), numeric (0-9), or the underscore
+# mark (_). (Essentially, the perl regex \w).
+
 # Command-line arguments [USERNAME]
 # Yes, but be very careful here (don't pass shell commands)
 # and this is only supported to allow perl-system calls.
@@ -36,6 +40,12 @@ use strict;
 # print "uh-oh" if $exitcode;
 
 # These are the exit codes.
+# ( (0,"ok"),
+#   (1,"User ID mismatch.  This program must be run as user 'www'"),
+#   (2,"Error. This program needs just 1 command-line argument (username).") )
+#   (3,"Error. Only one line should be entered into standard input."),
+#   (4,"Error. Too many other simultaneous password change requests being made."),
+#   (5,"Error. The user name specified has invalid characters.") )
 
 # Security
 $ENV{'PATH'}=""; # Nullify path information.
@@ -76,12 +86,14 @@ if (@ARGV==1) {
 }
 elsif (@ARGV) {
     print("Error. This program needs just 1 command-line argument (username).\n") unless $noprint;
+    unlink('/tmp/lock_lcpasswd');
     exit 2;
 }
 else {
     @input=<>;
     if (@input!=1) {
 	print("Error. Only one line should be entered into standard input.\n") unless $noprint;
+	unlink('/tmp/lock_lcpasswd');
 	exit 3;
     }
     map {chop} @input;
@@ -90,14 +102,21 @@ else {
 my ($username)=@input;
 $username=~/^(\w+)$/;
 my $safeusername=$1;
+if ($username ne $safeusername) {
+    print "Error. The user name specified has invalid characters.\n";
+    unlink('/tmp/lock_lcpasswd');
+    exit 5;
+}
 
 &enable_root_capability;
 
 # By using the system userdel command:
 # Remove entry from /etc/passwd if it exists
 # Remove entry from /etc/groups if it exists
-system('/usr/sbin/groupdel 2>/dev/null',$safeusername); # ignore error message
-system('/usr/sbin/userdel 2>/dev/null',$safeusername); # ignore error message
+# I surround with groupdel command to make absolutely sure the group definition disappears.
+system('/usr/sbin/groupdel',$safeusername); # ignore error message
+system('/usr/sbin/userdel',$safeusername); # ignore error message
+system('/usr/sbin/groupdel',$safeusername); # ignore error message
 
 # Remove entry from /etc/smbpasswd if it exists
 my $oldsmbpasswd=`/bin/cat /etc/smbpasswd`;