--- loncom/LONCAPA.pm	2006/06/19 09:35:08	1.6
+++ loncom/LONCAPA.pm	2006/06/26 21:19:36	1.8
@@ -1,7 +1,7 @@
 # The LearningOnline Network
 # Base routines
 #
-# $Id: LONCAPA.pm,v 1.6 2006/06/19 09:35:08 www Exp $
+# $Id: LONCAPA.pm,v 1.8 2006/06/26 21:19:36 foxr Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -40,9 +40,19 @@ my $loncapa_max_wait_time = 13;
 
 require Exporter;
 our @ISA = qw (Exporter);
-our @EXPORT = qw(&add_get_param &escape &unescape &tie_domain_hash &untie_domain_hash &tie_user_hash &untie_user_hash &propath);
+our @EXPORT = qw(&escape_LaTeX &add_get_param &escape &unescape &tie_domain_hash &untie_domain_hash &tie_user_hash &untie_user_hash &propath);
 my %perlvar;
 
+# Escape a LaTeX string of special characters that according to LaTeX line by line
+# pg 9 are: # $ % & \ ^ _ { } ~  These are escaped by prepending a \
+#
+sub escape_LaTeX {
+    my ($string) = @_;
+    $string =~ s/[\#\$\%\&\\^_{}]/\\$&/g;
+    return $string;
+}
+
+
 # Inputs are a url, and a hash ref of
 # form name => value pairs
 # takes care of properly adding the form name elements and values to the 
@@ -173,7 +183,7 @@ sub untie_user_hash {
 sub locking_hash_tie {
     my ($filename,$how)=@_;
     my ($file_prefix,$namespace)=&db_filename_parts($filename);
-    unless ($namespace) { return undef; }
+    if ($namespace eq '') { return undef; }
     return &_locking_hash_tie($file_prefix,$namespace,$how);
 }
 
@@ -184,7 +194,7 @@ sub locking_hash_untie {
 sub db_filename_parts {
     my ($filename)=@_;
     my ($file_path,$namespace)=($filename=~/^(.*)\/([^\/]+)\.db$/);
-    unless ($namespace) { return undef; }
+    if ($namespace eq '') { return undef; }
     return ($file_path.'/'.$namespace,$namespace);
 }