--- loncom/thesaurus/build_thesaurus_db.pl	2002/07/11 20:48:31	1.1
+++ loncom/thesaurus/build_thesaurus_db.pl	2003/08/05 15:51:37	1.2
@@ -1,6 +1,6 @@
 #!/usr/bin/perl -w
 #
-# $Id: build_thesaurus_db.pl,v 1.1 2002/07/11 20:48:31 matthew Exp $
+# $Id: build_thesaurus_db.pl,v 1.2 2003/08/05 15:51:37 matthew Exp $
 #
 #
 # build_thesaurus_db.pl creates the LON-CAPA thesaurus database.
@@ -124,13 +124,15 @@ build_thesaurus_db.pl --badwordfile ./un
 ##
 ## Get command line parameters
 ##
-my ($badwordfile,$outputdbfile,$keywordfile,$help,$test);
+my ($badwordfile,$outputdbfile,$keywordfile,$help,$checkdates,$test);
 GetOptions( "badwordfile=s" => \$badwordfile,   # --badwordfile
             "outputdb=s"    => \$outputdbfile,  # --outputdb
             "keywordfile=s" => \$keywordfile,   # --keywordfile
             "help"          => \$help,          # --help
+            "checkdates"    => \$checkdates,    # --checkdates
             "test"          => \$test);         # --test
 
+
 ##
 ## Help! Help!
 ##
@@ -143,6 +145,9 @@ Command line arguements
                                 put in the thesaurus.  Each word must appear
                                 on its own line and currently comments are not
                                 supported.
+   --checkdates                 Check the creation dates on the files involved
+                                and only run if the outputdb file was created
+                                prior to one of the badword or keyword files.
    --keywordfile <filename>     File containing the raw word data for the
                                 thesaurus.  Each line must be comma seperated
                                 list of related keywords.
@@ -171,6 +176,25 @@ foreach my $file ($badwordfile,$keywordf
     die "$file does not exist." if (! -e $file);
 }
 
+#
+# Check the dates on the input files to be sure we need to run
+if ($checkdates && -s $outputdbfile) {
+    my @Results = stat($badwordfile);
+    my $highest_dependency_ctime = $Results[10];
+    foreach ($keywordfile) {
+        if ($Results[10] > $highest_dependency_ctime) {
+            $highest_dependency_ctime = $Results[10];
+        }
+    }
+    #
+    # if the outputdbfile was made AFTER the last version of one of the
+    # dependencies, exit quietly.
+    @Results = stat($outputdbfile);
+    if ($highest_dependency_ctime < $Results[10]) { 
+        exit;
+    }
+}
+
 ##
 ## Global hashes.
 ##