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    1: #!/usr/bin/perl
    2: 
    3: =pod
    4: 
    5: =head1 NAME
    6: 
    7: make_domain_coordinator.pl - Make a domain coordinator on a LON-CAPA system
    8: 
    9: =cut
   10: 
   11: # The LearningOnline Network
   12: # make_domain_coordinator.pl - Make a domain coordinator on a system
   13: #
   14: # $Id: make_domain_coordinator.pl,v 1.28 2021/01/08 00:38:07 raeburn Exp $
   15: #
   16: # This file is part of the LearningOnline Network with CAPA (LON-CAPA).
   17: #
   18: # LON-CAPA is free software; you can redistribute it and/or modify
   19: # it under the terms of the GNU General Public License as published by
   20: # the Free Software Foundation; either version 2 of the License, or
   21: # (at your option) any later version.
   22: #
   23: # LON-CAPA is distributed in the hope that it will be useful,
   24: # but WITHOUT ANY WARRANTY; without even the implied warranty of
   25: # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   26: # GNU General Public License for more details.
   27: #
   28: # You should have received a copy of the GNU General Public License
   29: # along with LON-CAPA; if not, write to the Free Software
   30: # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
   31: #
   32: # /home/httpd/html/adm/gpl.txt
   33: #
   34: # http://www.lon-capa.org/
   35: #
   36: ###
   37: 
   38: =pod
   39: 
   40: =head1 DESCRIPTION
   41: 
   42: Automates the steps for domain coordinator creation.  This
   43: program also describes a manual procedure (see below).
   44: 
   45: These are the steps that are executed on the linux operating system:
   46: 
   47: =over 4
   48: 
   49: =item * 
   50: 
   51: Tests to see if user already exists for linux system or for
   52: LON-CAPA, if so aborts.  A message is output that recommends following
   53: a manual procedure enabling this user if so desired.
   54: 
   55: =item *
   56: 
   57: Creates a linux system user
   58: 
   59: =item *
   60: 
   61: Sets password
   62: 
   63: =item *
   64: 
   65: Creates a LON-CAPA lonUsers directory for user
   66: 
   67: =item *
   68: 
   69: Sets LON-CAPA password mechanism to be "unix"
   70: 
   71: =item *
   72: 
   73: Set roles.hist and roles.db
   74: 
   75: =back
   76: 
   77: =cut
   78: 
   79: # NOTE: I am interspersing the manual procedure with the automation.
   80: # To see the manual procedure, do perldoc ./make_domain_coordinator.pl
   81: 
   82: # This is a standalone script.  It *could* alternatively use the
   83: # lcuseradd script, however lcuseradd relies on certain system
   84: # dependencies.  In order to have a focused performance, I am trying
   85: # to avoid system dependencies until the LON-CAPA code base becomes
   86: # more robust and well-boundaried.  make_domain_coordinator.pl should be able
   87: # to run freely as possible, irrespective of the status of a LON-CAPA
   88: # installation.
   89: 
   90: # ---------------------------------------------------- Configure general values
   91: 
   92: use lib '/home/httpd/lib/perl/';
   93: use LONCAPA;
   94: use LONCAPA::lonmetadata;
   95: use Term::ReadKey;
   96: use Apache::lonnet;
   97: use Apache::lonlocal;
   98: use DBI;
   99: use Storable qw(nfreeze);
  100: use Sys::Hostname::FQDN();
  101: use strict;
  102: 
  103: =pod
  104: 
  105: =head1 OPTIONS
  106: 
  107: There are no flags to this script.
  108: 
  109: usage: make_domain_coordinator.pl [USERNAME] [DOMAIN] 
  110: 
  111: The password is accepted through standard input
  112: and should only consist of printable ASCII
  113: characters and be a string of length greater than 5 characters.
  114: 
  115: The first argument
  116: specifies the user name of the domain coordinator and
  117: should consist of only alphanumeric characters.
  118: It is recommended that the USERNAME should be institution-specific
  119: as opposed to something like "Sammy" or "Jo".
  120: For example, "dcmsu" or "dcumich" would be good domain coordinator
  121: USERNAMEs for places like Mich State Univ, etc.
  122: 
  123: The second argument specifies the domain of the computer
  124: coordinator.
  125: 
  126: =cut
  127: 
  128: my $lang = &Apache::lonlocal::choose_language();
  129: &Apache::lonlocal::get_language_handle(undef,$lang);
  130: print"\n";
  131: 
  132: # ----------------------------------------------- So, are we invoked correctly?
  133: # Two arguments or abort
  134: if (@ARGV!=2) {
  135:     print(&mt('usage: [_1]','make_domain_coordinator.pl [USERNAME] [DOMAIN]')."\n\n".
  136:         &mt('It is recommended that the USERNAME should be institution-specific.').
  137: 	"\n".&mt('It should not be something like "Sammy" or "Jo".')."\n".
  138: 	&mt('For example, [_1] or [_2] would be good domain coordinator USERNAMEs for places like Michigan State University, etc.','"domcoordmsu"','"dcmichstate"')."\n");
  139:     exit;
  140: }
  141: my ($username,$domain)=(@ARGV);
  142: if ($username=~/$LONCAPA::not_username_re/) {
  143:     print(&mt('**** ERROR **** Username [_1] must consist only of - . and alphanumeric characters.',$username)."\n");
  144:     exit;
  145: }
  146: if ($domain=~/$LONCAPA::not_domain_re/) {
  147:     print(&mt('**** ERROR **** Domain [_1] must consist only of - . and alphanumeric characters.',$domain)."\n");
  148:     exit;
  149: }
  150: 
  151: # Does user already exist
  152: my ($is_user,$has_lc_account);
  153: 
  154: my $udpath=&propath($domain,$username);
  155: if (-d $udpath) {
  156:     $has_lc_account = 1;
  157: }
  158: 
  159: if ($has_lc_account) {
  160:     print(&mt('**** ERROR **** [_1] is already defined as a LON-CAPA user.',
  161:               $username)."\n\n".
  162:           &mt('To assign a domain coordinator role to an existing user, use: [_1]',
  163:               "\n".'perl add_domain_coordinator_privilege.pl')."\n\n");
  164:     exit;
  165: }
  166: 
  167: if (-d "/home/$username") {
  168:     $is_user = 1;
  169: }
  170: 
  171: if ($is_user) {
  172:     print(&mt('**** ERROR **** [_1] is already a linux operating system user.',
  173:               $username)."\n\n".
  174:           &mt('This script will only automatically generate new users.')."\n".
  175:           &mt('To assign a domain coordinator role to an existing user:')."\n\n".
  176:           &mt('If you want to make "[_1]" a domain coordinator, you should do so manually by customizing the MANUAL PROCEDURE described in the documentation.',$username)."\n\n".
  177:           &mt('To view the documentation for this script, type: [_1].',
  178:               "\n".'perldoc ./make_domain_coordinator.pl')."\n\n");
  179:     exit;
  180: }
  181: 
  182: # Output a warning message.
  183: print(&mt('**** NOTE **** Generating a domain coordinator is "serious business".')."\n".
  184:      &mt('You must choose a password that is difficult to guess.')."\n");
  185: 
  186: print(&mt('Continue? ~[Y/n~] '));
  187: my $go_on = <STDIN>;
  188: chomp($go_on);
  189: $go_on =~ s/(^\s+|\s+$)//g;
  190: my $yes = &mt('y');
  191: unless (($go_on eq '') || ($go_on =~ /^\Q$yes\E/i)) {
  192:     exit;
  193: }
  194: print "\n";
  195: 
  196: my ($got_passwd,$firstpass,$secondpass,$passwd);
  197: my $maxtries = 10;
  198: my $trial = 0;
  199: while ((!$got_passwd) && ($trial < $maxtries)) {
  200:     $firstpass = &get_password(&mt('Enter password'));
  201:     if (length($firstpass) < 6) {
  202:         print(&mt('Password too short.')."\n".
  203:               &mt('Please choose a password with at least six characters.')."\n".
  204:               &mt('Please try again.')."\n");
  205:     } elsif (length($firstpass) > 30) {
  206:         print(&mt('Password too long.')."\n".
  207:               &mt('Please choose a password with no more than thirty characters.')."\n".
  208:               &mt('Please try again.')."\n");
  209:     } else {
  210:         my $pbad=0;
  211:         foreach (split(//,$firstpass)) {if ((ord($_)<32)||(ord($_)>126)){$pbad=1;}}
  212:         if ($pbad) {
  213:             print(&mt('Password contains invalid characters.')."\n".
  214:                   &mt('Password must consist of standard ASCII characters.')."\n".
  215:                   &mt('Please try again.')."\n");
  216:         } else {
  217:             $secondpass = &get_password(&mt('Enter password a second time'));
  218:             if ($firstpass eq $secondpass) {
  219:                 $got_passwd = 1;
  220:                 $passwd = $firstpass;
  221:             } else {
  222:                 print(&mt('Passwords did not match.')."\n". 
  223:                       &mt('Please try again.')."\n");
  224:             }
  225:         }
  226:         $trial ++;
  227:     }
  228: }
  229: if (!$got_passwd) {
  230:     exit;
  231: }
  232: print "\n";
  233: 
  234: =pod
  235: 
  236: =head1 MANUAL PROCEDURE
  237: 
  238: There are 10 steps to manually recreating what this script performs
  239: automatically.
  240: 
  241: You need to decide on three pieces of information
  242: to create a domain coordinator.
  243: 
  244:  * USERNAME (kermit, albert, joe, etc)
  245:  * DOMAIN (should be the same as lonDefDomain in /etc/httpd/conf/loncapa.conf)
  246:  * PASSWORD (don't tell me)
  247: 
  248: The examples in these instructions will be based
  249: on three example pieces of information:
  250: 
  251:  * USERNAME=dc103
  252:  * DOMAIN=103
  253:  * PASSWORD=sesame
  254: 
  255: You will also need to know your "root" password
  256: and your "www" password.
  257: 
  258: =over 4
  259: 
  260: =item 1.
  261: 
  262: login as root on your Linux system
  263:  [prompt %] su
  264: 
  265: =cut
  266: 
  267: # ------------------------------------------------------------ So, are we root?
  268: 
  269: if ($< != 0) { # Am I root?
  270:    print(&mt('You must be root in order to generate a domain coordinator.').
  271:          "\n");
  272: }
  273: 
  274: =pod
  275: 
  276: =item 2 (as root). add the user
  277: 
  278:  Command: [prompt %] /usr/sbin/useradd USERNAME
  279:  Example: [prompt %] /usr/sbin/useradd dc103
  280: 
  281: =cut
  282: 
  283: # ----------------------------------------------------------- /usr/sbin/groupadd
  284: # -- Add group
  285: $username=~s/\W//g; # an extra filter, just to be sure
  286: 
  287: print(&mt('adding group: [_1]',$username)."\n");
  288: my $status = system('/usr/sbin/groupadd', $username);
  289: if ($status) {
  290:     print(&mt('Error.').' '.
  291:           &mt('Something went wrong with the addition of group "[_1]".',
  292:               $username)."\n");
  293:     exit;
  294: }
  295: my $gid = getgrnam($username);
  296: 
  297: # ----------------------------------------------------------- /usr/sbin/useradd
  298: # -- Add user
  299: 
  300: print(&mt('adding user: [_1]',$username)."\n");
  301: my $status = system('/usr/sbin/useradd','-c','LON-CAPA user','-g',$gid,$username);
  302: if ($status) {
  303:     system("/usr/sbin/groupdel $username");
  304:     print(&mt('Error.').' '.
  305:           &mt('Something went wrong with the addition of user "[_1]".',
  306:               $username)."\n");
  307:     exit;
  308: }
  309: 
  310: print(&mt('Done adding user.')."\n");
  311: # Make www a member of that user group.
  312: my $groups=`/usr/bin/groups www`;
  313: # untaint
  314: my ($safegroups)=($groups=~/:\s*([\s\w]+)/);
  315: $groups=$safegroups;
  316: chomp $groups; $groups=~s/^\S+\s+\:\s+//;
  317: my @grouplist=split(/\s+/,$groups);
  318: my @ugrouplist=grep {!/www|$username/} @grouplist;
  319: my $gl=join(',',(@ugrouplist,$username));
  320: print(&mt("Putting www in user's group.")."\n");
  321: if (system('/usr/sbin/usermod','-G',$gl,'www')) {
  322:     print(&mt('Error.').' '.&mt('Could not make www a member of the group "[_1]".',
  323:               $username)."\n");
  324:     exit;
  325: }
  326: 
  327: # Check if home directory exists for user
  328: # If not, create one.
  329: if (!-e "/home/$username") {
  330:     if (!mkdir("/home/$username",0710)) {
  331:         print(&mt('Error.').' '.&mt('Could not add home directory for "[_1]".',
  332:                   $username)."\n");
  333:         exit;
  334:     }
  335: }
  336: 
  337: if (-d "/home/$username") {
  338:     system('/bin/chown',"$username:$username","/home/$username");
  339:     system('/bin/chmod','-R','0660',"/home/$username");
  340:     system('/bin/chmod','0710',"/home/$username");
  341: }
  342: =pod
  343: 
  344: =item 3 (as root). enter in a password
  345: 
  346:  Command: [prompt %] passwd USERNAME
  347:           New UNIX password: PASSWORD
  348:           Retype new UNIX passwd: PASSWORD
  349:  Example: [prompt %] passwd dc103
  350:           New UNIX password: sesame
  351:           Retype new UNIX passwd: sesame
  352: 
  353: =cut
  354: 
  355: # Process password (taint-check, then pass to the UNIX passwd command).
  356: $username =~ s/\W//g; # an extra filter, just to be sure
  357: my $pbad = 0;
  358: foreach (split(//,$passwd)) {if ((ord($_)<32)||(ord($_)>126)){$pbad=1;}}
  359: if ($pbad) {
  360:     print(&mt('Password must consist of standard ASCII characters.').
  361:           "\n");
  362: }
  363:  
  364: my ($distro,$nostdin);
  365: if (open(PIPE,"perl distprobe|")) {
  366:     $distro = <PIPE>;
  367:     close(PIPE);
  368: }
  369: if ($distro =~ /^ubuntu|debian/) {
  370:     $nostdin = 1;
  371: } elsif ($distro =~ /^suse([\d.]+)$/) {
  372:     if ($1 > 12.2) {
  373:         $nostdin = 1;
  374:     }
  375: } elsif ($distro =~ /^sles(\d+)$/) {
  376:     if ($1 > 11) {
  377:         $nostdin = 1;
  378:     }
  379: }
  380: if ($nostdin) {
  381:     open(OUT,"|usermod -p `mkpasswd $passwd` $username");
  382:     close(OUT);
  383: } else {
  384:     open(OUT,"|passwd --stdin $username");
  385:     print(OUT $passwd."\n");
  386:     close(OUT);
  387: }
  388: 
  389: =pod
  390: 
  391: =cut
  392: 
  393: =pod
  394: 
  395: =item 4. login as user=www
  396: 
  397:  Command: [prompt %] su www
  398:  Password: WWWPASSWORD
  399: 
  400: =item 5. (as www). cd /home/httpd/lonUsers
  401: 
  402: =item 6. (as www) Create user directory for your new user.
  403: 
  404:  Let U equal first letter of USERNAME
  405:  Let S equal second letter of USERNAME
  406:  Let E equal third letter of USERNAME
  407:  Command: [prompt %] install -d DOMAIN/U/S/E/USERNAME
  408: 
  409:  Here are three examples of the commands that would be needed
  410:  for different domain coordinator names (dc103, morphy, or ng):
  411: 
  412:  Example #1 (dc103):  [prompt %] install -d 103/d/c/1/dc103
  413:  Example #2 (morphy): [prompt %] install -d 103/m/o/r/morphy
  414:  Example #3 (ng):     [prompt %] install -d 103/n/g/_/ng
  415: 
  416: =cut
  417: 
  418: # Generate the user directory.
  419: `install -o www -g www -d $udpath`; # Must be writeable by httpd process.
  420: 
  421: =pod
  422: 
  423: =item 7. (as www) Enter the newly created user directory.
  424: 
  425:  Command: [prompt %] cd DOMAIN/U/S/E/USERNAME
  426:  Example: [prompt %] cd 103/d/c/1/dc103
  427: 
  428: =item 8. (as www). Set your password mechanism to 'unix' 
  429: 
  430:  Command: [prompt %] echo "unix:" > passwd
  431: 
  432: =cut
  433: 
  434: # UNIX (/etc/passwd) style authentication is asserted for domain coordinators.
  435: open(OUT, ">$udpath/passwd");
  436: print(OUT 'unix:'."\n");
  437: close(OUT);
  438: 
  439: # Get permissions correct on udpath
  440: 
  441:  print(&mt('Setting permissions on user data directories.').' '.
  442:        &mt('This may take a moment, please be patient ...')."\n");
  443: `chown -R www:www /home/httpd/lonUsers/$domain` ; # Must be writeable by httpd process.
  444: 
  445: =pod
  446: 
  447: =item 9. (as www). Run CVS:loncapa/doc/rolesmanip.pl:
  448: 
  449:  Command: [prompt %] perl rolesmanip.pl DOMAIN USERNAME
  450:  Example: [prompt %] perl rolesmanip.pl 103 dc103
  451: 
  452: =cut
  453: 
  454: use GDBM_File; # A simplistic key-value pairing database.
  455: 
  456: my $rolesref=&LONCAPA::locking_hash_tie("$udpath/roles.db",&GDBM_WRCREAT());
  457: if (!$rolesref) {
  458:     print(&mt('Error').' '.
  459:           &mt('unable to tie roles db: [_1].',"$udpath/roles.db")."\n");
  460:     exit;
  461: }
  462: my $now = time;
  463: $rolesref->{'/'.$domain.'/_dc'}='dc_0_'.$now; # Set the domain coordinator role.
  464: open(OUT, ">$udpath/roles.hist"); # roles.hist is the synchronous plain text.
  465: foreach my $key (keys(%{$rolesref})) {
  466:     print(OUT $key.' : '.$rolesref->{$key}."\n");
  467: }
  468: close(OUT);
  469: &LONCAPA::locking_hash_untie($rolesref);
  470: 
  471: 
  472: `chown www:www $udpath/roles.hist`; # Must be writeable by httpd process.
  473: `chown www:www $udpath/roles.db`; # Must be writeable by httpd process.
  474: 
  475: my %perlvar = %{&LONCAPA::Configuration::read_conf('loncapa.conf')};
  476: my $dompath = $perlvar{'lonUsersDir'}.'/'.$domain;
  477: my $domrolesref = &LONCAPA::locking_hash_tie("$dompath/nohist_domainroles.db",&GDBM_WRCREAT());
  478: 
  479: if (!$domrolesref) {
  480:     print(&mt('Error').' '.&mt('unable to tie nohist_domainroles db: [_1].',
  481:                                "$dompath/nohist_domainroles.db")."\n");
  482: }
  483: 
  484: # Store in nohist_domainroles.db
  485: my $domkey=&LONCAPA::escape('dc:'.$username.':'.$domain.'::'.$domain.':');
  486: $domrolesref->{$domkey}= &LONCAPA::escape('0:'.$now);
  487: &LONCAPA::locking_hash_untie($domrolesref);
  488: 
  489:  system('/bin/chown',"www:www","$dompath/nohist_domainroles.db"); # Must be writeable by httpd process.
  490:  system('/bin/chown',"www:www","$dompath/nohist_domainroles.db.lock");
  491: 
  492: # Log with domainconfiguser in nohist_rolelog.db
  493: my $domconfiguser = $domain.'-domainconfig';
  494: my $subdir = $domconfiguser;
  495: $subdir =~ s/(.)(.)(.).*/$1\/$2\/$3/;
  496: $subdir .= "/$domconfiguser";
  497: 
  498: if (-d "$dompath/$subdir") {
  499:     my $rolelogref = &LONCAPA::locking_hash_tie("$dompath/$subdir/nohist_rolelog.db",&GDBM_WRCREAT());
  500:     my $domlogkey = &LONCAPA::escape($now.'00000'.$$.'000000'); 
  501:     my $storehash = {
  502:                        role    => 'dc',
  503:                        start   => $now,
  504:                        end     => 0,
  505:                        context => 'server',
  506:                     };
  507:     my $domlogvalue = {
  508:                         'exe_uname' => '',
  509:                         'exe_udom'  => $domain,
  510:                         'exe_time'  => $now,
  511:                         'exe_ip'    => '127.0.0.1',
  512:                         'delflag'   => '',
  513:                         'logentry'  => $storehash,
  514:                         'uname'     => $username,
  515:                         'udom'      => $domain,
  516:                      };
  517:     $rolelogref->{$domlogkey}=&freeze_escape($domlogvalue);
  518:     &LONCAPA::locking_hash_untie($rolelogref);
  519: 
  520:     system('/bin/chown',"www:www","$dompath/$subdir/nohist_rolelog.db"); # Must be writeable by httpd process.
  521:     system('/bin/chown',"www:www","$dompath/$subdir/nohist_rolelog.db.lock");
  522: } else {
  523:     print(&mt('Failed to log role creation as the path to the directory: "[_1]" does not exist.',"$dompath/$subdir/")."\n".
  524:           &mt('Please run UPDATE from the top level directory of the extracted LON-CAPA tarball, i.e., two levels up from this current directory (loncom/build).'));
  525: }
  526: 
  527: #Update allusers MySQL table
  528: 
  529: print(&mt('Adding new user to allusers table.')."\n");
  530: &allusers_update($username,$domain,\%perlvar);
  531: 
  532: =pod
  533: 
  534: =item 10.
  535: 
  536: You may further define the domain coordinator user (i.e. dc103)
  537: by going to http://MACHINENAME/adm/createuser.
  538: 
  539: =cut
  540: 
  541: # Output success message, and inform sysadmin about how to further proceed.
  542: print("\n".&mt('[_1] is now a domain coordinator',$username)."\n"); # Output success message.
  543: my $hostname = Sys::Hostname::FQDN::fqdn(); # Read in hostname.
  544: print("\n".
  545:       &mt('Once LON-CAPA is running, you should log-in and use: [_1] to further define this user.',
  546:           "\nhttp://$hostname/adm/createuser\n")."\n\n".
  547:       &mt('From the user management menu, click the link: "Add/Modify a User" to search for the user and to provide additional information (last name, first name etc.).')."\n"); 
  548: # Output a suggested URL.
  549: 
  550: sub allusers_update {
  551:     my ($username,$domain,$perlvar) = @_;
  552:     my %tablenames = (
  553:                        'allusers'   => 'allusers',
  554:                      );
  555:     my $dbh;
  556:     unless ($dbh = DBI->connect("DBI:mysql:loncapa","www",
  557:                             $perlvar->{'lonSqlAccess'},
  558:                             { RaiseError =>0,PrintError=>0})) {
  559:         print(&mt('Cannot connect to database!')."\n");
  560:         return;
  561:     }
  562:     my $tablechk = &allusers_table_exists($dbh);
  563:     if ($tablechk == 0) {
  564:         my $request =
  565:    &LONCAPA::lonmetadata::create_metadata_storage('allusers','allusers');
  566:         $dbh->do($request);
  567:         if ($dbh->err) {
  568:              print(&mt('Failed to create [_1] table.','allusers')."\n");
  569:              return;
  570:         }
  571:     }
  572:     my %userdata =  (
  573:                 username => $username,
  574:                 domain   => $domain,
  575:     );
  576:     my %loghash =
  577:         &LONCAPA::lonmetadata::process_allusers_data($dbh,undef,
  578:             \%tablenames,$username,$domain,\%userdata,'update');
  579:     foreach my $key (keys(%loghash)) {
  580:         print $loghash{$key}."\n";
  581:     }
  582:     return;
  583: }
  584: 
  585: sub allusers_table_exists {
  586:     my ($dbh) = @_;
  587:     my $sth=$dbh->prepare('SHOW TABLES');
  588:     $sth->execute();
  589:     my $aref = $sth->fetchall_arrayref;
  590:     $sth->finish();
  591:     if ($sth->err()) {
  592:         return undef;
  593:     }
  594:     my $result = 0;
  595:     foreach my $table (@{$aref}) {
  596:         if ($table->[0] eq 'allusers') {
  597:             $result = 1;
  598:             last;
  599:         }
  600:     }
  601:     return $result;
  602: }
  603: 
  604: sub get_password {
  605:     my ($prompt) = @_;
  606:     local $| = 1;
  607:     print $prompt.': ';
  608:     my $newpasswd = '';
  609:     ReadMode 'raw';
  610:     my $key;
  611:     while(ord($key = ReadKey(0)) != 10) {
  612:         if(ord($key) == 127 || ord($key) == 8) {
  613:             chop($newpasswd);
  614:             print "\b \b";
  615:         } elsif(!ord($key) < 32) {
  616:             $newpasswd .= $key;
  617:             print '*';
  618:         }
  619:     }
  620:     ReadMode 'normal';
  621:     print "\n";
  622:     return $newpasswd;
  623: }
  624: 
  625: sub freeze_escape {
  626:     my ($value)=@_;
  627:     if (ref($value)) {
  628:         $value=&nfreeze($value);
  629:         return '__FROZEN__'.&LONCAPA::escape($value);
  630:     }
  631:     return &LONCAPA::escape($value);
  632: }
  633: 
  634: =pod
  635: 
  636: =head1 AUTHOR
  637: 
  638: Written to help the LON-CAPA project.
  639: 
  640: =cut
  641: