3 # Copyright 2000-2002 Katipo Communications
5 # This file is part of Koha.
7 # Koha is free software; you can redistribute it and/or modify it under the
8 # terms of the GNU General Public License as published by the Free Software
9 # Foundation; either version 2 of the License, or (at your option) any later
12 # Koha is distributed in the hope that it will be useful, but WITHOUT ANY
13 # WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
14 # A PARTICULAR PURPOSE. See the GNU General Public License for more details.
16 # You should have received a copy of the GNU General Public License along with
17 # Koha; if not, write to the Free Software Foundation, Inc., 59 Temple Place,
18 # Suite 330, Boston, MA 02111-1307 USA
26 use vars qw($VERSION @ISA @EXPORT $debug $cgi_debug);
27 # use vars qw(@EXPORT_OK %EXPORT_TAGS);
30 $VERSION = 1.00; # set the version for version checking
32 @EXPORT = qw($debug $cgi_debug);
34 # %EXPORT_TAGS = ( all=>[qw($debug $cgi_debug)], );
38 # this stuff needs a begin block too, since dependencies might alter their compilations
39 # for example, adding DataDumper
40 my $query = CGI->new();
41 $debug = $ENV{KOHA_DEBUG} || $ENV{DEBUG} || 0;
42 $cgi_debug = $ENV{KOHA_CGI_DEBUG} || $query->param('debug') || 0;
43 unless (0 <= $debug and $debug <= 9) {
44 warn "Invalid \$debug value attempted: $debug";
47 unless (0 <= $cgi_debug and $cgi_debug <= 9) {
49 warn "Invalid \$cgi_debug value attempted: $cgi_debug";
55 # print STDERR __PACKAGE__ . " (Debug) import @_\n";
56 # C4::Debug->export_to_level(1, @_);
64 C4::Debug - Standardized, centralized, exported debug switches.
72 The purpose of this module is to centralize some of the "switches" that turn debugging
73 off and on in Koha. Most often, this functionality will be provided via C4::Context.
74 C4::Debug is separate to preserve the relatively stable state of Context, and
75 because other code will use C4::Debug without invoking Context.
77 Although centralization is our intention,
78 for logical and security reasons, several approaches to debugging need to be
79 kept separate. Information useful to developers in one area will not necessarily
80 be useful or even available to developers in another area.
82 For example, the designer of template-influenced javascript my want to be able to
83 trigger javascript's alert function to display certain variable values, to verify
84 the template selection is being performed correctly. For this purpose the presence
85 of a javascript "debug" variable might be a good switch.
87 Meanwhile, where security coders (say, for LDAP Auth) will appreciate low level feedback about
88 Authentication transactions, an environmental system variable might be a good switch.
89 However, clearly we would not want to expose that same information (e.g., entire LDAP records)
90 to the web interface based on a javascript variable (even if it were possible)!
92 All that is a long way of saying THERE ARE SECURITY IMPLICATIONS to turning on
93 debugging in various parts of the system, so don't treat them all the same or confuse them.
95 =head1 VARIABLES / AREAS
97 =head2 $debug - System, general
98 The general purpose debug switch.
100 =head3 How to Set $debug:
104 =item environmental variable DEBUG or KOHA_DEBUG. In bash, you might do:
109 =item Keep in mind that your webserver will not be running in the same environment as your shell.
110 However, for development purposes, the same effect can be had by using Apache's SET_ENV
111 command with ERROR_LOG enabled for your VirtualHost. Not intended for production systems.
113 =item You can force the value from perl directly, like:
117 BEGIN { $C4::Debug::debug = 1; }
118 # now any other dependencies that also use C4::Debug will have debugging ON.
122 =head2 $cgi_debug (CGI params) The web-based debug switch.
124 =head3 How to Set $cgi_debug:
128 =item From a web browser, for example by supplying a non-zero debug parameter:
130 http://www.mylibrary.org/cgi-bin/koha/opac-search.pl?q=history&debug=1
132 =item Or in HTML, add a similar input parameter:
134 <input type="hidden" name="debug" value="1" />
136 =item Or from shell (or Apache), set KOHA_CGI_DEBUG.
140 The former methods mean $cgi_debug is exposed. Do NOT use it to trigger any actions that you would
141 not allow a (potentially anonymous) end user to perform.
143 =head1 OTHER SOURCES of Debug Switches
145 =head2 System Preferences
147 =head2 Database Debug
149 Debugging at the database level might be useful. Koha does not currently integrate any such
154 Debug values range from 0 to 9. At zero (the default), debugging is off.
159 atz AT liblime DOT com