[LON-CAPA-cvs] cvs: loncom / lonsql

matthew lon-capa-cvs@mail.lon-capa.org
Tue, 06 Aug 2002 13:48:47 -0000


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matthew		Tue Aug  6 09:48:47 2002 EDT

  Modified files:              
    /loncom	lonsql 
  Log:
  Many, many changes.
  THIS CODE SHOULD NOT BE USED AT THIS TIME.  It does not run. 
  
  Added POD comments everywhere.
  Now use File::Find instead of requiring find.pl, which I could never find.
  Now use strict.
  Rearranged most of the code.
  Added &do_sql_query.
  &userlog and &courselog were not modified but were moved.
  
  
--matthew1028641727
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Index: loncom/lonsql
diff -u loncom/lonsql:1.50 loncom/lonsql:1.51
--- loncom/lonsql:1.50	Fri Jul  5 11:07:59 2002
+++ loncom/lonsql	Tue Aug  6 09:48:47 2002
@@ -3,7 +3,7 @@
 # The LearningOnline Network
 # lonsql - LON TCP-MySQL-Server Daemon for handling database requests.
 #
-# $Id: lonsql,v 1.50 2002/07/05 15:07:59 matthew Exp $
+# $Id: lonsql,v 1.51 2002/08/06 13:48:47 matthew Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -27,32 +27,30 @@
 #
 # http://www.lon-capa.org/
 #
-# YEAR=2000
-# lonsql-based on the preforker:harsha jagasia:date:5/10/00
-# 7/25 Gerd Kortemeyer
-# many different dates Scott Harrison
-# YEAR=2001
-# many different dates Scott Harrison
-# 03/22/2001 Scott Harrison
-# 8/30 Gerd Kortemeyer
-# 10/17,11/28,11/29,12/20 Scott Harrison
-# YEAR=2001
-# 5/11 Scott Harrison
-#
-###
-
-###############################################################################
-##                                                                           ##
-## ORGANIZATION OF THIS PERL SCRIPT                                          ##
-## 1. Modules used                                                           ##
-## 2. Enable find subroutine                                                 ##
-## 3. Read httpd config files and get variables                              ##
-## 4. Make sure that database can be accessed                                ##
-## 5. Make sure this process is running from user=www                        ##
-## 6. Check if other instance is running                                     ##
-## 7. POD (plain old documentation, CPAN style)                              ##
-##                                                                           ##
-###############################################################################
+
+=pod
+
+=head1 NAME
+
+lonsql - LON TCP-MySQL-Server Daemon for handling database requests.
+
+=head1 SYNOPSIS
+
+This script should be run as user=www.  
+Note that a lonsql.pid file contains the pid of the parent process.
+
+=head1 DESCRIPTION
+
+lonsql is many things to many people.  To me, it is a source file in need
+of documentation.
+
+=head1 Internals
+
+=over 4
+
+=cut
+
+use strict;
 
 use lib '/home/httpd/lib/perl/';
 use LONCAPA::Configuration;
@@ -66,90 +64,90 @@
 use Fcntl;
 use Tie::RefHash;
 use DBI;
+use File::Find;
 
-my @metalist;
-# ----------------- Code to enable 'find' subroutine listing of the .meta files
-require "find.pl";
-sub wanted {
-    (($dev,$ino,$mode,$nlink,$uid,$gid) = lstat($_)) &&
-    -f _ &&
-    /^.*\.meta$/ && !/^.+\.\d+\.[^\.]+\.meta$/ &&
-    push(@metalist,"$dir/$_");
-}
+########################################################
+########################################################
 
-$childmaxattempts=10;
-$run =0;#running counter to generate the query-id
+=pod
 
-# -------------------------------- Read loncapa_apache.conf and loncapa.conf
-my $perlvarref=LONCAPA::Configuration::read_conf('loncapa_apache.conf',
-                                                 'loncapa.conf');
-my %perlvar=%{$perlvarref};
+=item Global Variables
 
-# ------------------------------------- Make sure that database can be accessed
-{
-    my $dbh;
-    unless (
-	    $dbh = DBI->connect("DBI:mysql:loncapa","www",$perlvar{'lonSqlAccess'},{ RaiseError =>0,PrintError=>0})
-	    ) { 
-	print "Cannot connect to database!\n";
-	$emailto="$perlvar{'lonAdmEMail'},$perlvar{'lonSysEMail'}";
-	$subj="LON: $perlvar{'lonHostID'} Cannot connect to database!";
-	system("echo 'Cannot connect to MySQL database!' |\
- mailto $emailto -s '$subj' > /dev/null");
-	exit 1;
-    }
-    else {
-	$dbh->disconnect;
-    }
-}
+=over 4
 
-# --------------------------------------------- Check if other instance running
+=item dbh
 
-my $pidfile="$perlvar{'lonDaemons'}/logs/lonsql.pid";
+=back
 
-if (-e $pidfile) {
-   my $lfh=IO::File->new("$pidfile");
-   my $pide=<$lfh>;
-   chomp($pide);
-   if (kill 0 => $pide) { die "already running"; }
-}
+=cut
 
-# ------------------------------------------------------------- Read hosts file
-$PREFORK=4; # number of children to maintain, at least four spare
+########################################################
+########################################################
+my $dbh;
 
-open (CONFIG,"$perlvar{'lonTabDir'}/hosts.tab") || die "Can't read host file";
+########################################################
+########################################################
 
-while ($configline=<CONFIG>) {
-    my ($id,$domain,$role,$name,$ip)=split(/:/,$configline);
-    chomp($ip);
+=pod 
 
-    $hostip{$ip}=$id;
-    if ($id eq $perlvar{'lonHostID'}) { $thisserver=$name; }
+=item Variables required for forking
 
-    $PREFORK++;
-}
-close(CONFIG);
+=over 4
 
-$PREFORK=int($PREFORK/4);
+=item $MAX_CLIENTS_PER_CHILD
 
-$unixsock = "mysqlsock";
-my $localfile="$perlvar{'lonSockDir'}/$unixsock";
-my $server;
-unlink ($localfile);
-unless ($server=IO::Socket::UNIX->new(Local    =>"$localfile",
-				  Type    => SOCK_STREAM,
-				  Listen => 10))
-{
-    print "in socket error:$@\n";
-}
+The number of clients each child should process.
+
+=item %children 
+
+The keys to %children  are the current child process IDs
+
+=item $children
+
+The current number of children
+
+=back
+
+=cut 
 
-# -------------------------------------------------------- Routines for forking
-# global variables
-$MAX_CLIENTS_PER_CHILD  = 5;        # number of clients each child should process
-%children               = ();       # keys are current child process IDs
-$children               = 0;        # current number of children
+########################################################
+########################################################
+my $MAX_CLIENTS_PER_CHILD  = 5;   # number of clients each child should process
+my %children               = ();  # keys are current child process IDs
+my $children               = 0;   # current number of children
+                               
+########################################################
+########################################################
 
-sub REAPER {                        # takes care of dead children
+=pod
+
+=item Functions required for forking
+
+=over 4
+
+=item REAPER
+
+REAPER takes care of dead children.
+
+=item HUNTSMAN
+
+Signal handler for SIGINT.
+
+=item HUPSMAN
+
+Signal handler for SIGHUP
+
+=item DISCONNECT
+
+Disconnects from database.
+
+=back
+
+=cut
+
+########################################################
+########################################################
+sub REAPER {                   # takes care of dead children
     $SIG{CHLD} = \&REAPER;
     my $pid = wait;
     $children --;
@@ -165,7 +163,7 @@
     &logthis("<font color=red>CRITICAL: Shutting down</font>");
     $unixsock = "mysqlsock";
     my $port="$perlvar{'lonSockDir'}/$unixsock";
-    unlink(port);
+    unlink($port);
     exit;                           # clean up with dignity
 }
 
@@ -177,157 +175,174 @@
     my $execdir=$perlvar{'lonDaemons'};
     $unixsock = "mysqlsock";
     my $port="$perlvar{'lonSockDir'}/$unixsock";
-    unlink(port);
+    unlink($port);
     exec("$execdir/lonsql");         # here we go again
 }
 
-sub logthis {
-    my $message=shift;
-    my $execdir=$perlvar{'lonDaemons'};
-    my $fh=IO::File->new(">>$execdir/logs/lonsqlfinal.log");
-    my $now=time;
-    my $local=localtime($now);
-    print $fh "$local ($$): $message\n";
+sub DISCONNECT {
+    $dbh->disconnect or 
+    &logthis("<font color=blue>WARNING: Couldn't disconnect from database ".
+             " $DBI::errstr : $@</font>");
+    exit;
 }
 
-# ------------------------------------------------------------------ Course log
+###################################################################
+###################################################################
 
-sub courselog {
-    my ($path,$command)=@_;
-    my %filters=();
-    foreach (split(/\:/,&unescape($command))) {
-	my ($name,$value)=split(/\=/,$_);
-        $filters{$name}=$value;
-    }
-    my @results=();
-    open(IN,$path.'/activity.log') or return ('file_error');
-    while ($line=<IN>) {
-        chomp($line);
-        my ($timestamp,$host,$log)=split(/\:/,$line);
-#
-# $log has the actual log entries; currently still escaped, and
-# %26(timestamp)%3a(url)%3a(user)%3a(domain)
-# then additionally
-# %3aPOST%3a(name)%3d(value)%3a(name)%3d(value)
-# or
-# %3aCSTORE%3a(name)%3d(value)%26(name)%3d(value)
-#
-# get delimiter between timestamped entries to be &&&
-        $log=~s/\%26(\d+)\%3a/\&\&\&$1\%3a/g;
-# now go over all log entries 
-        foreach (split(/\&\&\&/,&unescape($log))) {
-	    my ($time,$res,$uname,$udom,$action,@values)=split(/\:/,$_);
-            my $values=&unescape(join(':',@values));
-            $values=~s/\&/\:/g;
-            $res=&unescape($res);
-            my $include=1;
-            if (($filters{'username'}) && ($uname ne $filters{'username'})) 
-                                                               { $include=0; }
-            if (($filters{'domain'}) && ($udom ne $filters{'domain'})) 
-                                                               { $include=0; }
-            if (($filters{'url'}) && ($res!~/$filters{'url'}/)) 
-                                                               { $include=0; }
-            if (($filters{'start'}) && ($time<$filters{'start'})) 
-                                                               { $include=0; }
-            if (($filters{'end'}) && ($time>$filters{'end'})) 
-                                                               { $include=0; }
-            if (($filters{'action'} eq 'view') && ($action)) 
-                                                               { $include=0; }
-            if (($filters{'action'} eq 'submit') && ($action ne 'POST')) 
-                                                               { $include=0; }
-            if (($filters{'action'} eq 'grade') && ($action ne 'CSTORE')) 
-                                                               { $include=0; }
-            if ($include) {
-	       push(@results,($time<1000000000?'0':'').$time.':'.$res.':'.
-                                            $uname.':'.$udom.':'.
-                                            $action.':'.$values);
-            }
-       }
-    }
-    close IN;
-    return join('&',sort(@results));
-}
+=pod
 
-# -------------------------------------------------------------------- User log
+=item Main body of code.
 
-sub userlog {
-    my ($path,$command)=@_;
-    my %filters=();
-    foreach (split(/\:/,&unescape($command))) {
-	my ($name,$value)=split(/\=/,$_);
-        $filters{$name}=$value;
-    }
-    my @results=();
-    open(IN,$path.'/activity.log') or return ('file_error');
-    while ($line=<IN>) {
-        chomp($line);
-        my ($timestamp,$host,$log)=split(/\:/,$line);
-        $log=&unescape($log);
-        my $include=1;
-        if (($filters{'start'}) && ($timestamp<$filters{'start'})) 
-                                                             { $include=0; }
-        if (($filters{'end'}) && ($timestamp>$filters{'end'})) 
-                                                             { $include=0; }
-        if (($filters{'action'} eq 'log') && ($log!~/^Log/)) { $include=0; }
-        if (($filters{'action'} eq 'check') && ($log!~/^Check/)) 
-                                                             { $include=0; }
-        if ($include) {
-	   push(@results,$timestamp.':'.$log);
-        }
-    }
-    close IN;
-    return join('&',sort(@results));
-}
+=over 4
 
+=item Read data from loncapa_apache.conf and loncapa.conf.
 
-# ---------------------------------------------------- Fork once and dissociate
-$fpid=fork;
-exit if $fpid;
-die "Couldn't fork: $!" unless defined ($fpid);
+=item Ensure we can access the database.
 
-POSIX::setsid() or die "Can't start new session: $!";
+=item Determine if there are other instances of lonsql running.
+
+=item Read the hosts file.
+
+=item Create a socket for lonsql.
 
-# ------------------------------------------------------- Write our PID on disk
+=item Fork once and dissociate from parent.
 
-$execdir=$perlvar{'lonDaemons'};
+=item Write PID to disk.
+
+=item Prefork children and maintain the population of children.
+
+=back
+
+=cut
+
+###################################################################
+###################################################################
+my $childmaxattempts=10;
+my $run =0;              # running counter to generate the query-id
+#
+# Read loncapa_apache.conf and loncapa.conf
+#
+my $perlvarref=LONCAPA::Configuration::read_conf('loncapa_apache.conf',
+                                                 'loncapa.conf');
+my %perlvar=%{$perlvarref};
+#
+# Make sure that database can be accessed
+#
+my $dbh;
+unless ($dbh = DBI->connect("DBI:mysql:loncapa","www",
+                            $perlvar{'lonSqlAccess'},
+                            { RaiseError =>0,PrintError=>0})) { 
+    print "Cannot connect to database!\n";
+    my $emailto="$perlvar{'lonAdmEMail'},$perlvar{'lonSysEMail'}";
+    my $subj="LON: $perlvar{'lonHostID'} Cannot connect to database!";
+    system("echo 'Cannot connect to MySQL database!' |".
+           " mailto $emailto -s '$subj' > /dev/null");
+    exit 1;
+} else {
+    $dbh->disconnect;
+}
+#
+# Check if other instance running
+#
+my $pidfile="$perlvar{'lonDaemons'}/logs/lonsql.pid";
+if (-e $pidfile) {
+   my $lfh=IO::File->new("$pidfile");
+   my $pide=<$lfh>;
+   chomp($pide);
+   if (kill 0 => $pide) { die "already running"; }
+}
+#
+# Read hosts file
+#
+my %hostip;
+my $thisserver;
+my $PREFORK=4; # number of children to maintain, at least four spare
+open (CONFIG,"$perlvar{'lonTabDir'}/hosts.tab") || die "Can't read host file";
+while (my $configline=<CONFIG>) {
+    my ($id,$domain,$role,$name,$ip)=split(/:/,$configline);
+    chomp($ip);
+    $hostip{$ip}=$id;
+    $thisserver=$name if ($id eq $perlvar{'lonHostID'});
+    $PREFORK++;
+}
+close(CONFIG);
+#
+$PREFORK=int($PREFORK/4);
+#
+# Create a socket to talk to lond
+#
+my $unixsock = "mysqlsock";
+my $localfile="$perlvar{'lonSockDir'}/$unixsock";
+my $server;
+unlink ($localfile);
+unless ($server=IO::Socket::UNIX->new(Local    =>"$localfile",
+                                      Type    => SOCK_STREAM,
+                                      Listen => 10)) {
+    print "in socket error:$@\n";
+}
+########################################################
+########################################################
+#
+# Fork once and dissociate
+my $fpid=fork;
+exit if $fpid;
+die "Couldn't fork: $!" unless defined ($fpid);
+POSIX::setsid() or die "Can't start new session: $!";
+#
+# Write our PID on disk
+my $execdir=$perlvar{'lonDaemons'};
 open (PIDSAVE,">$execdir/logs/lonsql.pid");
 print PIDSAVE "$$\n";
 close(PIDSAVE);
 &logthis("<font color=red>CRITICAL: ---------- Starting ----------</font>");
-
-# ----------------------------- Ignore signals generated during initial startup
+#
+# Ignore signals generated during initial startup
 $SIG{HUP}=$SIG{USR1}='IGNORE';
-# ------------------------------------------------------- Now we are on our own    
-# Fork off our children.
+# Now we are on our own    
+#    Fork off our children.
 for (1 .. $PREFORK) {
     make_new_child();
 }
-
+#
 # Install signal handlers.
 $SIG{CHLD} = \&REAPER;
 $SIG{INT}  = $SIG{TERM} = \&HUNTSMAN;
 $SIG{HUP}  = \&HUPSMAN;
-
+#
 # And maintain the population.
 while (1) {
     sleep;                          # wait for a signal (i.e., child's death)
-    for ($i = $children; $i < $PREFORK; $i++) {
+    for (my $i = $children; $i < $PREFORK; $i++) {
         make_new_child();           # top up the child pool
     }
 }
 
+########################################################
+########################################################
+
+=pod
+
+=item &make_new_child
+
+Inputs: None
+
+Returns: None
+
+=cut
 
+########################################################
+########################################################
 sub make_new_child {
     my $pid;
     my $sigset;
-    
+    #
     # block signal for fork
     $sigset = POSIX::SigSet->new(SIGINT);
     sigprocmask(SIG_BLOCK, $sigset)
         or die "Can't block SIGINT for fork: $!\n";
-    
+    #
     die "fork: $!" unless defined ($pid = fork);
-    
+    #
     if ($pid) {
         # Parent records the child's birth and returns.
         sigprocmask(SIG_UNBLOCK, $sigset)
@@ -338,178 +353,85 @@
     } else {
         # Child can *not* return from this subroutine.
         $SIG{INT} = 'DEFAULT';      # make SIGINT kill us as it did before
-    
         # unblock signals
         sigprocmask(SIG_UNBLOCK, $sigset)
             or die "Can't unblock SIGINT for fork: $!\n";
-	
-	
         #open database handle
 	# making dbh global to avoid garbage collector
-	unless (
-		$dbh = DBI->connect("DBI:mysql:loncapa","www",$perlvar{'lonSqlAccess'},{ RaiseError =>0,PrintError=>0})
-		) { 
-  	            sleep(10+int(rand(20)));
-		    &logthis("<font color=blue>WARNING: Couldn't connect to database  ($st secs): $@</font>");
-		    print "database handle error\n";
-		    exit;
-
-	  };
-	# make sure that a database disconnection occurs with ending kill signals
+	unless ($dbh = DBI->connect("DBI:mysql:loncapa","www",
+                                    $perlvar{'lonSqlAccess'},
+                                    { RaiseError =>0,PrintError=>0})) { 
+            sleep(10+int(rand(20)));
+            &logthis("<font color=blue>WARNING: Couldn't connect to database".
+                     ": $@</font>");
+                     #  "($st secs): $@</font>");
+            print "database handle error\n";
+            exit;
+        }
+	# make sure that a database disconnection occurs with 
+        # ending kill signals
 	$SIG{TERM}=$SIG{INT}=$SIG{QUIT}=$SIG{__DIE__}=\&DISCONNECT;
-
         # handle connections until we've reached $MAX_CLIENTS_PER_CHILD
-        for ($i=0; $i < $MAX_CLIENTS_PER_CHILD; $i++) {
-            $client = $server->accept()     or last;
-            
+        for (my $i=0; $i < $MAX_CLIENTS_PER_CHILD; $i++) {
+            my $client = $server->accept() or last;
             # do something with the connection
 	    $run = $run+1;
 	    my $userinput = <$client>;
 	    chomp($userinput);
-	    	    
+            #
 	    my ($conserver,$query,
 		$arg1,$arg2,$arg3)=split(/&/,$userinput);
 	    my $query=unescape($query);
-
+            #
             #send query id which is pid_unixdatetime_runningcounter
-	    $queryid = $thisserver;
+	    my $queryid = $thisserver;
 	    $queryid .="_".($$)."_";
 	    $queryid .= time."_";
 	    $queryid .= $run;
 	    print $client "$queryid\n";
-	    
+	    #
 	    &logthis("QUERY: $query - $arg1 - $arg2 - $arg3");
 	    sleep 1;
-
+            #
             my $result='';
-
-# ---------- At this point, query is received, query-ID assigned and sent back 
-# $query eq 'logquery' will mean that this is a query against log-files
-
-
-	   if (($query eq 'userlog') || ($query eq 'courselog')) {
-# ----------------------------------------------------- beginning of log query
-#
-# this goes against a user's log file
-#
-	       my $udom=&unescape($arg1);
-	       my $uname=&unescape($arg2);
-               my $command=&unescape($arg3);
-               my $path=&propath($udom,$uname);
-               if (-e "$path/activity.log") {
-		   if ($query eq 'userlog') {
-                       $result=&userlog($path,$command);
-                   } else {
-                       $result=&courselog($path,$command);
-                   }
-               } else {
-		   &logthis('Unable to do log query: '.$uname.'@'.$udom);
-	           $result='no_such_file';
-	       }
-# ------------------------------------------------------------ end of log query
-          } else {
-# -------------------------------------------------------- This is an sql query
-	    my $custom=unescape($arg1);
-	    my $customshow=unescape($arg2);
-            #prepare and execute the query
-	    my $sth = $dbh->prepare($query);
-
-	    my @files;
-	    my $subsetflag=0;
-	    if ($query) {
-		unless ($sth->execute())
-		{
-		    &logthis("<font color=blue>WARNING: Could not retrieve from database: $@</font>");
-		    $result="";
-		}
-		else {
-		    my $r1=$sth->fetchall_arrayref;
-		    my @r2;
-		    foreach (@$r1) {my $a=$_; 
-			 my @b=map {escape($_)} @$a;
-			 push @files,@{$a}[3];
-			 push @r2,join(",", @b)
-			 }
-		    $result=join("&",@r2);
-		}
-	    }
-	    # do custom metadata searching here and build into result
-	    if ($custom or $customshow) {
-		&logthis("am going to do custom query for $custom");
-		if ($query) {
-		    @metalist=map {$perlvar{'lonDocRoot'}.$_.'.meta'} @files;
-		}
-		else {
-		    @metalist=(); pop @metalist;
-		    opendir(RESOURCES,"$perlvar{'lonDocRoot'}/res/$perlvar{'lonDefDomain'}");
-		    my @homeusers=grep
-		          {&ishome("$perlvar{'lonDocRoot'}/res/$perlvar{'lonDefDomain'}/$_")}
-		          grep {!/^\.\.?$/} readdir(RESOURCES);
-		    closedir RESOURCES;
-		    foreach my $user (@homeusers) {
-			&find("$perlvar{'lonDocRoot'}/res/$perlvar{'lonDefDomain'}/$user");
-		    }
-		}
-#		&logthis("FILELIST:" . join(":::",@metalist));
-		# if file is indicated in sql database and
-		# not part of sql-relevant query, do not pattern match.
-		# if file is not in sql database, output error.
-		# if file is indicated in sql database and is
-		# part of query result list, then do the pattern match.
-		my $customresult='';
-		my @r2;
-		foreach my $m (@metalist) {
-		    my $fh=IO::File->new($m);
-		    my @lines=<$fh>;
-		    my $stuff=join('',@lines);
-		    if ($stuff=~/$custom/s) {
-			foreach my $f ('abstract','author','copyright',
-				       'creationdate','keywords','language',
-				       'lastrevisiondate','mime','notes',
-				       'owner','subject','title') {
-			    $stuff=~s/\n?\<$f[^\>]*\>.*?<\/$f[^\>]*\>\n?//s;
-			}
-			my $m2=$m; my $docroot=$perlvar{'lonDocRoot'};
-			$m2=~s/^$docroot//;
-			$m2=~s/\.meta$//;
-			unless ($query) {
-			    my $q2="select * from metadata where url like binary '$m2'";
-			    my $sth = $dbh->prepare($q2);
-			    $sth->execute();
-			    my $r1=$sth->fetchall_arrayref;
-			    foreach (@$r1) {my $a=$_; 
-				 my @b=map {escape($_)} @$a;
-				 push @files,@{$a}[3];
-				 push @r2,join(",", @b)
-				 }
-			}
-#			&logthis("found: $stuff");
-			$customresult.='&custom='.escape($m2).','.escape($stuff);
-		    }
-		}
-		$result=join("&",@r2) unless $query;
-		$result.=$customresult;
-	    }
-# ------------------------------------------------------------ end of sql query
-	   }
-
+            #
+            # At this point, query is received, query-ID assigned and sent 
+            # back, $query eq 'logquery' will mean that this is a query 
+            # against log-files
+            if (($query eq 'userlog') || ($query eq 'courselog')) {
+                # beginning of log query
+                my $udom    = &unescape($arg1);
+                my $uname   = &unescape($arg2);
+                my $command = &unescape($arg3);
+                my $path    = &propath($udom,$uname);
+                if (-e "$path/activity.log") {
+                    if ($query eq 'userlog') {
+                        $result=&userlog($path,$command);
+                    } else {
+                        $result=&courselog($path,$command);
+                    }
+                } else {
+                    &logthis('Unable to do log query: '.$uname.'@'.$udom);
+                    $result='no_such_file';
+                }
+                # end of log query
+            } else {
+                # Do an sql query
+                $result = &do_sql_query($query,$arg1,$arg2);
+            }
             # result does not need to be escaped because it has already been
             # escaped.
             #$result=&escape($result);
-
-	    # reply with result, append \n unless already there
-
+            # reply with result, append \n unless already there
 	    $result.="\n" unless ($result=~/\n$/);
             &reply("queryreply:$queryid:$result",$conserver);
-
         }
-    
         # tidy up gracefully and finish
-	
-        #close the database handle
+        #
+        # close the database handle
 	$dbh->disconnect
-	   or &logthis("<font color=blue>WARNING: Couldn't disconnect from database  $DBI::errstr ($st secs): $@</font>");
-    
+            or &logthis("<font color=blue>WARNING: Couldn't disconnect".
+                        " from database  $DBI::errstr : $@</font>");
         # this exit is VERY important, otherwise the child will become
         # a producer of more and more children, forking yourself into
         # process death.
@@ -517,14 +439,178 @@
     }
 }
 
-sub DISCONNECT {
-    $dbh->disconnect or 
-    &logthis("<font color=blue>WARNING: Couldn't disconnect from database  $DBI::errstr ($st secs): $@</font>");
-    exit;
+########################################################
+########################################################
+
+=pod
+
+=item &do_sql_query
+
+Runs an sql metadata table query.
+
+Inputs: $query, $custom, $customshow
+
+Returns: A string containing escaped results.
+
+=cut
+
+########################################################
+########################################################
+{
+    my @metalist;
+
+sub process_file {
+    if ( -e $_ &&  # file exists
+         -f $_ &&  # and is a normal file
+         /\.meta$/ &&  # ends in meta
+         ! /^.+\.\d+\.[^\.]+\.meta$/  # is not a previous version
+         ) {
+        push(@metalist,$File::Find::name);
+    }
+}
+
+sub do_sql_query {
+    my ($query,$custom,$customshow) = @_;
+    $custom     = &unescape($custom);
+    $customshow = &unescape($customshow);
+    #
+    @metalist = ();
+    #
+    my $result = '';
+    my @results = ();
+    my @files;
+    my $subsetflag=0;
+    #
+    if ($query) {
+        #prepare and execute the query
+        my $sth = $dbh->prepare($query);
+        unless ($sth->execute()) {
+            &logthis("<font color=blue>WARNING: ".
+                     "Could not retrieve from database: $@</font>");
+        } else {
+            my $aref=$sth->fetchall_arrayref;
+            foreach my $row (@$aref) {
+                push @files,@{$row}[3] if ($custom or $customshow);
+                my @b=map { &escape($_); } @$row;
+                push @results,join(",", @b);
+                # Build up the @files array with the LON-CAPA urls 
+                # of the resources.
+            }
+        }
+    }
+    # do custom metadata searching here and build into result
+    return join("&",@results) if (! ($custom or $customshow));
+    # Only get here if there is a custom query or custom show request
+    &logthis("Doing custom query for $custom");
+    if ($query) {
+        @metalist=map {
+            $perlvar{'lonDocRoot'}.$_.'.meta';
+        } @files;
+    } else {
+        my $dir = "$perlvar{'lonDocRoot'}/res/$perlvar{'lonDefDomain'}";
+        @metalist=(); 
+        opendir(RESOURCES,$dir);
+        my @homeusers=grep {
+            &ishome($dir.'/'.$_);
+        } grep {!/^\.\.?$/} readdir(RESOURCES);
+        closedir RESOURCES;
+        # Define the
+        foreach my $user (@homeusers) {
+            find (\&process_file,$dir.'/'.$user);
+        }
+    } 
+    # if file is indicated in sql database and
+    #     not part of sql-relevant query, do not pattern match.
+    #
+    # if file is not in sql database, output error.
+    #
+    # if file is indicated in sql database and is
+    #     part of query result list, then do the pattern match.
+    my $customresult='';
+    my @results;
+    foreach my $metafile (@metalist) {
+        my $fh=IO::File->new($metafile);
+        my @lines=<$fh>;
+        my $stuff=join('',@lines);
+        if ($stuff=~/$custom/s) {
+            foreach my $f ('abstract','author','copyright',
+                           'creationdate','keywords','language',
+                           'lastrevisiondate','mime','notes',
+                           'owner','subject','title') {
+                $stuff=~s/\n?\<$f[^\>]*\>.*?<\/$f[^\>]*\>\n?//s;
+            }
+            my $mfile=$metafile; 
+            my $docroot=$perlvar{'lonDocRoot'};
+            $mfile=~s/^$docroot//;
+            $mfile=~s/\.meta$//;
+            unless ($query) {
+                my $q2="SELECT * FROM metadata WHERE url ".
+                    " LIKE BINARY '?'";
+                my $sth = $dbh->prepare($q2);
+                $sth->execute($mfile);
+                my $aref=$sth->fetchall_arrayref;
+                foreach my $a (@$aref) {
+                    my @b=map { &escape($_)} @$a;
+                    push @results,join(",", @b);
+                }
+            }
+            # &logthis("found: $stuff");
+            $customresult.='&custom='.&escape($mfile).','.
+                escape($stuff);
+        }
+    }
+    $result=join("&",@results) unless $query;
+    $result.=$customresult;
+    #
+    return $result;
+} # End of &do_sql_query
+
+} # End of scoping curly braces for &process_file and &do_sql_query
+########################################################
+########################################################
+
+=pod
+
+=item &logthis
+
+Inputs: $message, the message to log
+
+Returns: nothing
+
+Writes $message to the logfile.
+
+=cut
+
+########################################################
+########################################################
+sub logthis {
+    my $message=shift;
+    my $execdir=$perlvar{'lonDaemons'};
+    my $fh=IO::File->new(">>$execdir/logs/lonsqlfinal.log");
+    my $now=time;
+    my $local=localtime($now);
+    print $fh "$local ($$): $message\n";
 }
 
 # -------------------------------------------------- Non-critical communication
 
+########################################################
+########################################################
+
+=pod
+
+=item &subreply
+
+Sends a command to a server.  Called only by &reply.
+
+Inputs: $cmd,$server
+
+Returns: The results of the message or 'con_lost' on error.
+
+=cut
+
+########################################################
+########################################################
 sub subreply {
     my ($cmd,$server)=@_;
     my $peerfile="$perlvar{'lonSockDir'}/$server";
@@ -535,10 +621,27 @@
     print $sclient "$cmd\n";
     my $answer=<$sclient>;
     chomp($answer);
-    if (!$answer) { $answer="con_lost"; }
+    $answer="con_lost" if (!$answer);
     return $answer;
 }
 
+########################################################
+########################################################
+
+=pod
+
+=item &reply
+
+Sends a command to a server.
+
+Inputs: $cmd,$server
+
+Returns: The results of the message or 'con_lost' on error.
+
+=cut
+
+########################################################
+########################################################
 sub reply {
   my ($cmd,$server)=@_;
   my $answer;
@@ -555,24 +658,70 @@
   return $answer;
 }
 
-# -------------------------------------------------------- Escape Special Chars
+########################################################
+########################################################
+
+=pod
+
+=item &escape
+
+Escape special characters in a string.
 
+Inputs: string to escape
+
+Returns: The input string with special characters escaped.
+
+=cut
+
+########################################################
+########################################################
 sub escape {
     my $str=shift;
     $str =~ s/(\W)/"%".unpack('H2',$1)/eg;
     return $str;
 }
 
-# ----------------------------------------------------- Un-Escape Special Chars
+########################################################
+########################################################
+
+=pod
+
+=item &unescape
+
+Unescape special characters in a string.
 
+Inputs: string to unescape
+
+Returns: The input string with special characters unescaped.
+
+=cut
+
+########################################################
+########################################################
 sub unescape {
     my $str=shift;
     $str =~ s/%([a-fA-F0-9][a-fA-F0-9])/pack("C",hex($1))/eg;
     return $str;
 }
 
-# --------------------------------------- Is this the home server of an author?
-# (copied from lond, modification of the return value)
+########################################################
+########################################################
+
+=pod
+
+=item &ishome
+
+Determine if the current machine is the home server for a user.
+The determination is made by checking the filesystem for the users information.
+
+Inputs: $author
+
+Returns: 0 - this is not the authors home server, 1 - this is.
+
+=cut
+
+########################################################
+########################################################
 sub ishome {
     my $author=shift;
     $author=~s/\/home\/httpd\/html\/res\/([^\/]*)\/([^\/]*).*/$1\/$2/;
@@ -585,8 +734,21 @@
     }
 }
 
-# -------------------------------------------- Return path to profile directory
-# (copied from lond)
+########################################################
+########################################################
+
+=pod
+
+=item &propath
+
+Inputs: user name, user domain
+
+Returns: The full path to the users directory.
+
+=cut
+
+########################################################
+########################################################
 sub propath {
     my ($udom,$uname)=@_;
     $udom=~s/\W//g;
@@ -597,74 +759,135 @@
     return $proname;
 } 
 
-# ----------------------------------- POD (plain old documentation, CPAN style)
+########################################################
+########################################################
 
-=head1 NAME
+=pod
 
-lonsql - LON TCP-MySQL-Server Daemon for handling database requests.
+=item &courselog
 
-=head1 SYNOPSIS
+Inputs: $path, $command
 
-This script should be run as user=www.  The following is an example invocation
-from the loncron script.  Note that a lonsql.pid file contains the pid of
-the parent process.
-
-    if (-e $lonsqlfile) {
-	my $lfh=IO::File->new("$lonsqlfile");
-	my $lonsqlpid=<$lfh>;
-	chomp($lonsqlpid);
-	if (kill 0 => $lonsqlpid) {
-	    print $fh "<h3>lonsql at pid $lonsqlpid responding</h3>";
-	    $restartflag=0;
-	} else {
-	    $errors++; $errors++;
-	    print $fh "<h3>lonsql at pid $lonsqlpid not responding</h3>";
-		$restartflag=1;
-	print $fh 
-	    "<h3>Decided to clean up stale .pid file and restart lonsql</h3>";
-	}
-    }
-    if ($restartflag==1) {
-	$errors++;
-	         print $fh '<br><font color="red">Killall lonsql: '.
-                    system('killall lonsql').' - ';
-                    sleep 60;
-                    print $fh unlink($lonsqlfile).' - '.
-                              system('killall -9 lonsql').
-                    '</font><br>';
-	print $fh "<h3>lonsql not running, trying to start</h3>";
-	system(
- "$perlvar{'lonDaemons'}/lonsql 2>>$perlvar{'lonDaemons'}/logs/lonsql_errors");
-	sleep 10;
+Returns: unescaped string of values.
 
-=head1 DESCRIPTION
+=cut
+
+########################################################
+########################################################
+sub courselog {
+    my ($path,$command)=@_;
+    my %filters=();
+    foreach (split(/\:/,&unescape($command))) {
+	my ($name,$value)=split(/\=/,$_);
+        $filters{$name}=$value;
+    }
+    my @results=();
+    open(IN,$path.'/activity.log') or return ('file_error');
+    while (my $line=<IN>) {
+        chomp($line);
+        my ($timestamp,$host,$log)=split(/\:/,$line);
+#
+# $log has the actual log entries; currently still escaped, and
+# %26(timestamp)%3a(url)%3a(user)%3a(domain)
+# then additionally
+# %3aPOST%3a(name)%3d(value)%3a(name)%3d(value)
+# or
+# %3aCSTORE%3a(name)%3d(value)%26(name)%3d(value)
+#
+# get delimiter between timestamped entries to be &&&
+        $log=~s/\%26(\d+)\%3a/\&\&\&$1\%3a/g;
+# now go over all log entries 
+        foreach (split(/\&\&\&/,&unescape($log))) {
+	    my ($time,$res,$uname,$udom,$action,@values)=split(/\:/,$_);
+            my $values=&unescape(join(':',@values));
+            $values=~s/\&/\:/g;
+            $res=&unescape($res);
+            my $include=1;
+            if (($filters{'username'}) && ($uname ne $filters{'username'})) 
+                                                               { $include=0; }
+            if (($filters{'domain'}) && ($udom ne $filters{'domain'})) 
+                                                               { $include=0; }
+            if (($filters{'url'}) && ($res!~/$filters{'url'}/)) 
+                                                               { $include=0; }
+            if (($filters{'start'}) && ($time<$filters{'start'})) 
+                                                               { $include=0; }
+            if (($filters{'end'}) && ($time>$filters{'end'})) 
+                                                               { $include=0; }
+            if (($filters{'action'} eq 'view') && ($action)) 
+                                                               { $include=0; }
+            if (($filters{'action'} eq 'submit') && ($action ne 'POST')) 
+                                                               { $include=0; }
+            if (($filters{'action'} eq 'grade') && ($action ne 'CSTORE')) 
+                                                               { $include=0; }
+            if ($include) {
+	       push(@results,($time<1000000000?'0':'').$time.':'.$res.':'.
+                                            $uname.':'.$udom.':'.
+                                            $action.':'.$values);
+            }
+       }
+    }
+    close IN;
+    return join('&',sort(@results));
+}
 
-Not yet written.
+########################################################
+########################################################
 
-=head1 README
+=pod
+
+=item &userlog
+
+Inputs: $path, $command
+
+Returns: unescaped string of values.
+
+=cut
+
+########################################################
+########################################################
+sub userlog {
+    my ($path,$command)=@_;
+    my %filters=();
+    foreach (split(/\:/,&unescape($command))) {
+	my ($name,$value)=split(/\=/,$_);
+        $filters{$name}=$value;
+    }
+    my @results=();
+    open(IN,$path.'/activity.log') or return ('file_error');
+    while (my $line=<IN>) {
+        chomp($line);
+        my ($timestamp,$host,$log)=split(/\:/,$line);
+        $log=&unescape($log);
+        my $include=1;
+        if (($filters{'start'}) && ($timestamp<$filters{'start'})) 
+                                                             { $include=0; }
+        if (($filters{'end'}) && ($timestamp>$filters{'end'})) 
+                                                             { $include=0; }
+        if (($filters{'action'} eq 'log') && ($log!~/^Log/)) { $include=0; }
+        if (($filters{'action'} eq 'check') && ($log!~/^Check/)) 
+                                                             { $include=0; }
+        if ($include) {
+	   push(@results,$timestamp.':'.$log);
+        }
+    }
+    close IN;
+    return join('&',sort(@results));
+}
 
-Not yet written.
 
-=head1 PREREQUISITES
 
-IO::Socket
-Symbol
-POSIX
-IO::Select
-IO::File
-Socket
-Fcntl
-Tie::RefHash
-DBI
 
-=head1 COREQUISITES
 
-=head1 OSNAMES
 
-linux
 
-=head1 SCRIPT CATEGORIES
 
-Server/Process
+
+
+
+# ----------------------------------- POD (plain old documentation, CPAN style)
+
+=pod
+
+=back
 
 =cut

--matthew1028641727--