# HG changeset patch
# User Eris Caffee <discordia@eldalin.com>
# Date 1311012284 18000
# Node ID 462ba4c70c6566d8e34ea245f43e70d2939ded83
# Parent  065d2beb69a574c54a2e3fc2d40a482f93a9d474
Eliminated global vars (undeclared variables suck).  Added check for no username available.  Cleanup up test code.

diff -r 065d2beb69a5 -r 462ba4c70c65 make-username.pl
--- a/make-username.pl	Mon Jul 18 10:15:15 2011 -0500
+++ b/make-username.pl	Mon Jul 18 13:04:44 2011 -0500
@@ -28,6 +28,8 @@
 use English;
 use File::Basename;
 
+# main is a block.  NO GLOBALS!
+{
 my $base ="";
 my $user;
 my $debug = 0;
@@ -56,99 +58,78 @@
 }
 
 if (! $test) {
-    $user = make_username($base);
-    defined $user and printf("%s\n", $user);
+    $user = make_username($base, $maxlen);
+    if (defined $user) {
+	printf("%s\n", $user);
+    } else {
+	printf(STDERR "No username available\n");
+    }
     exit 0;
 } else {
     my $pwdfile = "passwd";
-    $base = "";
-    my $t1 = time;
-    $user = make_username($base, $pwdfile);
-    my $t2 = time;
-    defined $user and printf("%30s %-".$maxlen."s in %ds\n", $base, $user, $t2 - $t1);
+    my ($base, $t1, $t2); 
+    my @bases = ("", # should use default "user" as base.  user and user1 taken
+		 "eightchr",
+		 "short",
+		 "this *&% is not allowed &^$%&^m",
+		 "123digits",
+		 "this-is-a-domain.com",
+		 '&$%#&$*&$%*&',
+		 "testqwer", # testqwer taken
+		 "testabc", # all testabc? taken
+		 "testzx", # all testzx?? taken
+		 "test", # all test??? taken
+		 "t"	# all z????? taken though 10435
+		 );
+ 
+    foreach $base (@bases) {
+	$t1 = time;
+	$user = make_username($base, $maxlen, $pwdfile);
+	$t2 = time;
+	if (defined $user) {
+	    printf("%30s %-".$maxlen."s in %ds\n", $base, $user, $t2 - $t1);
+	} else {
+	    printf("%30s No username available\n", $base, $t2 - $t1);
+	}
+    }
     
-    $base = "eightchr";
+    $maxlen = 2;
+    $base = "z"; # all z? taken.  Should return no username.
     $t1 = time;
-    $user = make_username($base, $pwdfile);
+    $user = make_username($base, $maxlen, $pwdfile);
     $t2 = time;
-    defined $user and printf("%30s %-".$maxlen."s in %ds\n", $base, $user, $t2 - $t1);
+    if (defined $user) {
+	printf("%30s %-".$maxlen."s in %ds\n", $base, $user, $t2 - $t1);
+    } else {
+	printf("%30s No username available\n", $base, $t2 - $t1);
+    }
     
-    $base = "short";
-    $t1 = time;
-    $user = make_username($base, $pwdfile);
-    $t2 = time;
-    defined $user and printf("%30s %-".$maxlen."s in %ds\n", $base, $user, $t2 - $t1);
-    
-    $base = "this *&% is not allowed &^$%&^m";
-    $t1 = time;
-    $user = make_username($base, $pwdfile);
-    $t2 = time;
-    defined $user and printf("%30s %-".$maxlen."s in %ds\n", $base, $user, $t2 - $t1);
+}
 
-    $base = "123digits";
-    $t1 = time;
-    $user = make_username($base, $pwdfile);
-    $t2 = time;
-    defined $user and printf("%30s %-".$maxlen."s in %ds\n", $base, $user, $t2 - $t1);
-
-    $base = "this-is-a-domain.com";
-    $t1 = time;
-    $user = make_username($base, $pwdfile);
-    $t2 = time;
-    defined $user and printf("%30s %-".$maxlen."s in %ds\n", $base, $user, $t2 - $t1);
-
-    $base = '&$%#&$*&$%*&';
-    $t1 = time;
-    $user = make_username($base, $pwdfile);
-    $t2 = time;
-    defined $user and printf("%30s %-".$maxlen."s in %ds\n", $base, $user, $t2 - $t1);
-
-    $base = "testqwer";
-    $t1 = time;
-    $user = make_username($base, $pwdfile);
-    $t2 = time;
-    defined $user and printf("%30s %-".$maxlen."s in %ds\n", $base, $user, $t2 - $t1);
-
-    $base = "testabc";
-    $t1 = time;
-    $user = make_username($base, $pwdfile);
-    $t2 = time;
-    defined $user and printf("%30s %-".$maxlen."s in %ds\n", $base, $user, $t2 - $t1);
-
-    $base = "testzx";
-    $t1 = time;
-    $user = make_username($base, $pwdfile);
-    $t2 = time;
-    defined $user and printf("%30s %-".$maxlen."s in %ds\n", $base, $user, $t2 - $t1);
-
-    $base = "test";
-    $t1 = time;
-    $user = make_username($base, $pwdfile);
-    $t2 = time;
-    defined $user and printf("%30s %-".$maxlen."s in %ds\n", $base, $user, $t2 - $t1);
-
-    $base = "t";
-    $t1 = time;
-    $user = make_username($base, $pwdfile);
-    $t2 = time;
-    defined $user and printf("%30s %-".$maxlen."s in %ds\n", $base, $user, $t2 - $t1);
 }
+exit 0;
 
 ################################################################################
 sub make_username {
     # Arguments:
-    # The string to use as the basis of the new username.
-    # Can be any string (such as an existing username or a domain name)
-    # But at most 8 characters will be used.  Invalid characters will
-    # be removed.
-    # If the first character would be a number, an 'a' is prepended to the name.
-    # If blank, the string "user" will be used.
+    # $base The string to use as the basis of the new username.
+    #       Can be any string (such as an existing username or a domain name)
+    #       But at most $maxlen characters will be used.  Invalid characters will
+    #       be removed.
+    #       If the first character would be a number, an 'a' is prepended to the name.
+    #       If blank, the string "user" will be used.
+    # $maxlen The maximum length of the username to create.  If not specified, 
+    #       it defaults to 8. It must be 2 or more. (If it was 1 then there 
+    #       would be no way to prepend a number to it without having a digit as 
+    #       the first character of the new name.) 
+    # $pwdfile The name of the passwd file to use for checking for new users.
+    #       /etc/passwd by default.  This is really a debugging option.
     #
     # Returns:
     # A string containing the new username or undef if no username 
     # could be generated  (unlikely)
 
-    my ($base, $pwdfile) = @_;
+    my ($base, $maxlen, $pwdfile) = @_;
 
     if ($base eq "") {
 	$base = "user";
@@ -156,6 +137,15 @@
 
     ! defined $pwdfile and $pwdfile = "/etc/passwd";
 
+    if (! defined $maxlen) {
+	$maxlen = 8;
+    } else {
+	if ($maxlen !~ /^\d+$/) {
+	    printf(STDERR "Error: non-numeric username length specified.\n");
+	    return undef;
+	}
+    }
+
     if (! -e $pwdfile) {
 	printf(STDERR "Error: non-existant passwd file specified: $pwdfile\n");
 	return undef;
@@ -169,27 +159,27 @@
     }
 
     # Use the specified parameter as the base of the new username.
-    # Print it into a string of exactly 8 characters.
+    # Print it into a string of exactly $maxlen characters.
     # Print the number into the last portion of the new username.
     # Delete spaces (in case the passed username candidate was short).
     # Churn until we find an unused name.
-    my $tries=0;
     my $i=1;
     my $numstr;
     my $newuser = sprintf("%.".$maxlen."s", $base);
-
-    while ( (user_exists($newuser, $pwdfile)) && ($i < 10000000) ) { 
-	$tries = 1;
+   # print "maxlen $maxlen\n";
+    #print "newuser +$newuser+\n";
+    while ( (user_exists($newuser, $pwdfile)) && ($i < 10**($maxlen-1)) ) { 
 	$numstr = sprintf("%d", $i);
 	$newuser = sprintf("%-".$maxlen."s", $base);
+#    print "1 newuser $newuser\n";
 	substr($newuser, -length($numstr), length($numstr), $numstr);
+ #   print "2 newuser $newuser\n";
 	$newuser =~ s/ //g;
+  #  print "3 newuser $newuser\n";
         $i++;
-	$debug and printf(STDERR "Checking for $newuser\n");
     }
 
-    $i == 10000000 and return undef;
-    $debug and print "final is $newuser in $tries attempts\n";
+    $i >= 10**($maxlen-1) and return undef;
     return $newuser;
 }
 
diff -r 065d2beb69a5 -r 462ba4c70c65 passwd-huge.gz
Binary file passwd-huge.gz has changed