lib/CGI/Carp.pm

package CGI::Carp;

=head1 NAME

B<CGI::Carp> - CGI routines for writing to the HTTPD (or other) error log

=head1 SYNOPSIS

    use CGI::Carp;

    croak "We're outta here!";
    confess "It was my fault: $!";
    carp "It was your fault!";   
    warn "I'm confused";
    die  "I'm dying.\n";

    use CGI::Carp qw(cluck);
    cluck "I wouldn't do that if I were you";

    use CGI::Carp qw(fatalsToBrowser);
    die "Fatal error messages are now sent to browser";

=head1 DESCRIPTION

CGI scripts have a nasty habit of leaving warning messages in the error
logs that are neither time stamped nor fully identified.  Tracking down
the script that caused the error is a pain.  This fixes that.  Replace
the usual

    use Carp;

with

    use CGI::Carp

And the standard warn(), die (), croak(), confess() and carp() calls
will automagically be replaced with functions that write out nicely
time-stamped messages to the HTTP server error log.

For example:

   [Fri Nov 17 21:40:43 1995] test.pl: I'm confused at test.pl line 3.
   [Fri Nov 17 21:40:43 1995] test.pl: Got an error message: Permission denied.
   [Fri Nov 17 21:40:43 1995] test.pl: I'm dying.

=head1 REDIRECTING ERROR MESSAGES

By default, error messages are sent to STDERR.  Most HTTPD servers
direct STDERR to the server's error log.  Some applications may wish
to keep private error logs, distinct from the server's error log, or
they may wish to direct error messages to STDOUT so that the browser
will receive them.

The C<carpout()> function is provided for this purpose.  Since
carpout() is not exported by default, you must import it explicitly by
saying

   use CGI::Carp qw(carpout);

The carpout() function requires one argument, which should be a
reference to an open filehandle for writing errors.  It should be
called in a C<BEGIN> block at the top of the CGI application so that
compiler errors will be caught.  Example:

   BEGIN {
     use CGI::Carp qw(carpout);
     open(LOG, ">>/usr/local/cgi-logs/mycgi-log") or
       die("Unable to open mycgi-log: $!\n");
     carpout(LOG);
   }

carpout() does not handle file locking on the log for you at this point.

The real STDERR is not closed -- it is moved to CGI::Carp::SAVEERR.  Some
servers, when dealing with CGI scripts, close their connection to the
browser when the script closes STDOUT and STDERR.  CGI::Carp::SAVEERR is there to
prevent this from happening prematurely.

You can pass filehandles to carpout() in a variety of ways.  The "correct"
way according to Tom Christiansen is to pass a reference to a filehandle 
GLOB:

    carpout(\*LOG);

This looks weird to mere mortals however, so the following syntaxes are
accepted as well:

    carpout(LOG);
    carpout(main::LOG);
    carpout(main'LOG);
    carpout(\LOG);
    carpout(\'main::LOG');

    ... and so on

FileHandle and other objects work as well.

Use of carpout() is not great for performance, so it is recommended
for debugging purposes or for moderate-use applications.  A future
version of this module may delay redirecting STDERR until one of the
CGI::Carp methods is called to prevent the performance hit.

=head1 MAKING PERL ERRORS APPEAR IN THE BROWSER WINDOW

If you want to send fatal (die, confess) errors to the browser, ask to 
import the special "fatalsToBrowser" subroutine:

    use CGI::Carp qw(fatalsToBrowser);
    die "Bad error here";

Fatal errors will now be echoed to the browser as well as to the log.  CGI::Carp
arranges to send a minimal HTTP header to the browser so that even errors that
occur in the early compile phase will be seen.
Nonfatal errors will still be directed to the log file only (unless redirected
with carpout).

=head2 Changing the default message

By default, the software error message is followed by a note to
contact the Webmaster by e-mail with the time and date of the error.
If this message is not to your liking, you can change it using the
set_message() routine.  This is not imported by default; you should
import it on the use() line:

    use CGI::Carp qw(fatalsToBrowser set_message);
    set_message("It's not a bug, it's a feature!");

You may also pass in a code reference in order to create a custom
error message.  At run time, your code will be called with the text
of the error message that caused the script to die.  Example:

    use CGI::Carp qw(fatalsToBrowser set_message);
    BEGIN {
       sub handle_errors {
          my $msg = shift;
          print "<h1>Oh gosh</h1>";
          print "<p>Got an error: $msg</p>";
      }
      set_message(\&handle_errors);
    }

In order to correctly intercept compile-time errors, you should call
set_message() from within a BEGIN{} block.

=head1 MAKING WARNINGS APPEAR AS HTML COMMENTS

It is now also possible to make non-fatal errors appear as HTML
comments embedded in the output of your program.  To enable this
feature, export the new "warningsToBrowser" subroutine.  Since sending
warnings to the browser before the HTTP headers have been sent would
cause an error, any warnings are stored in an internal buffer until
you call the warningsToBrowser() subroutine with a true argument:

    use CGI::Carp qw(fatalsToBrowser warningsToBrowser);
    use CGI qw(:standard);
    print header();
    warningsToBrowser(1);

You may also give a false argument to warningsToBrowser() to prevent
warnings from being sent to the browser while you are printing some
content where HTML comments are not allowed:

    warningsToBrowser(0);    # disable warnings
    print "<script type=\"text/javascript\"><!--\n";
    print_some_javascript_code();
    print "//--></script>\n";
    warningsToBrowser(1);    # re-enable warnings

Note: In this respect warningsToBrowser() differs fundamentally from
fatalsToBrowser(), which you should never call yourself!

=head1 OVERRIDING THE NAME OF THE PROGRAM

CGI::Carp includes the name of the program that generated the error or
warning in the messages written to the log and the browser window.
Sometimes, Perl can get confused about what the actual name of the
executed program was.  In these cases, you can override the program
name that CGI::Carp will use for all messages.

The quick way to do that is to tell CGI::Carp the name of the program
in its use statement.  You can do that by adding
"name=cgi_carp_log_name" to your "use" statement.  For example:

    use CGI::Carp qw(name=cgi_carp_log_name);

.  If you want to change the program name partway through the program,
you can use the C<set_progname()> function instead.  It is not
exported by default, you must import it explicitly by saying

    use CGI::Carp qw(set_progname);

Once you've done that, you can change the logged name of the program
at any time by calling

    set_progname(new_program_name);

You can set the program back to the default by calling

    set_progname(undef);

Note that this override doesn't happen until after the program has
compiled, so any compile-time errors will still show up with the
non-overridden program name
  
=head1 CHANGE LOG

1.05 carpout() added and minor corrections by Marc Hedlund
     <hedlund@best.com> on 11/26/95.

1.06 fatalsToBrowser() no longer aborts for fatal errors within
     eval() statements.

1.08 set_message() added and carpout() expanded to allow for FileHandle
     objects.

1.09 set_message() now allows users to pass a code REFERENCE for 
     really custom error messages.  croak and carp are now
     exported by default.  Thanks to Gunther Birznieks for the
     patches.

1.10 Patch from Chris Dean (ctdean@cogit.com) to allow 
     module to run correctly under mod_perl.

1.11 Changed order of &gt; and &lt; escapes.

1.12 Changed die() on line 217 to CORE::die to avoid B<-w> warning.

1.13 Added cluck() to make the module orthogonal with Carp.
     More mod_perl related fixes.

1.20 Patch from Ilmari Karonen (perl@itz.pp.sci.fi):  Added
     warningsToBrowser().  Replaced <CODE> tags with <PRE> in
     fatalsToBrowser() output.

1.23 ineval() now checks both $^S and inspects the message for the "eval" pattern
     (hack alert!) in order to accomodate various combinations of Perl and
     mod_perl.

1.24 Patch from Scott Gifford (sgifford@suspectclass.com): Add support
     for overriding program name.

1.26 Replaced CORE::GLOBAL::die with the evil $SIG{__DIE__} because the
     former isn't working in some people's hands.  There is no such thing
     as reliable exception handling in Perl.

=head1 AUTHORS

Copyright 1995-2002, Lincoln D. Stein.  All rights reserved.  

This library is free software; you can redistribute it and/or modify
it under the same terms as Perl itself.

Address bug reports and comments to: lstein@cshl.org

=head1 SEE ALSO

Carp, CGI::Base, CGI::BasePlus, CGI::Request, CGI::MiniSvr, CGI::Form,
CGI::Response
    if (defined($CGI::Carp::PROGNAME)) 
    {
      $file = $CGI::Carp::PROGNAME;
    }

=cut

require 5.000;
use Exporter;
#use Carp;
BEGIN { 
  require Carp; 
  *CORE::GLOBAL::die = \&CGI::Carp::die;
}

use File::Spec;

@ISA = qw(Exporter);
@EXPORT = qw(confess croak carp);
@EXPORT_OK = qw(carpout fatalsToBrowser warningsToBrowser wrap set_message set_progname cluck ^name= die);

$main::SIG{__WARN__}=\&CGI::Carp::warn;

$CGI::Carp::VERSION    = '1.26';
$CGI::Carp::CUSTOM_MSG = undef;


# fancy import routine detects and handles 'errorWrap' specially.
sub import {
    my $pkg = shift;
    my(%routines);
    my(@name);
  
    if (@name=grep(/^name=/,@_))
      {
        my($n) = (split(/=/,$name[0]))[1];
        set_progname($n);
        @_=grep(!/^name=/,@_);
      }

    grep($routines{$_}++,@_,@EXPORT);
    $WRAP++ if $routines{'fatalsToBrowser'} || $routines{'wrap'};
    $WARN++ if $routines{'warningsToBrowser'};
    my($oldlevel) = $Exporter::ExportLevel;
    $Exporter::ExportLevel = 1;
    Exporter::import($pkg,keys %routines);
    $Exporter::ExportLevel = $oldlevel;
    $main::SIG{__DIE__} =\&CGI::Carp::die if $routines{'fatalsToBrowser'};
#    $pkg->export('CORE::GLOBAL','die');
}

# These are the originals
sub realwarn { CORE::warn(@_); }
sub realdie { CORE::die(@_); }

sub id {
    my $level = shift;
    my($pack,$file,$line,$sub) = caller($level);
    my($dev,$dirs,$id) = File::Spec->splitpath($file);
    return ($file,$line,$id);
}

sub stamp {
    my $time = scalar(localtime);
    my $frame = 0;
    my ($id,$pack,$file,$dev,$dirs);
    if (defined($CGI::Carp::PROGNAME)) {
        $id = $CGI::Carp::PROGNAME;
    } else {
        do {
          $id = $file;
          ($pack,$file) = caller($frame++);
        } until !$file;
    }
    ($dev,$dirs,$id) = File::Spec->splitpath($id);
    return "[$time] $id: ";
}

sub set_progname {
    $CGI::Carp::PROGNAME = shift;
    return $CGI::Carp::PROGNAME;
}


sub warn {
    my $message = shift;
    my($file,$line,$id) = id(1);
    $message .= " at $file line $line.\n" unless $message=~/\n$/;
    _warn($message) if $WARN;
    my $stamp = stamp;
    $message=~s/^/$stamp/gm;
    realwarn $message;
}

sub _warn {
    my $msg = shift;
    if ($EMIT_WARNINGS) {
        # We need to mangle the message a bit to make it a valid HTML
        # comment.  This is done by substituting similar-looking ISO
        # 8859-1 characters for <, > and -.  This is a hack.
        $msg =~ tr/<>-/\253\273\255/;
        chomp $msg;
        print STDOUT "<!-- warning: $msg -->\n";
    } else {
        push @WARNINGS, $msg;
    }
}


# The mod_perl package Apache::Registry loads CGI programs by calling
# eval.  These evals don't count when looking at the stack backtrace.
sub _longmess {
    my $message = Carp::longmess();
    $message =~ s,eval[^\n]+(ModPerl|Apache)/Registry\w*\.pm.*,,s
        if exists $ENV{MOD_PERL};
    return $message;
}

sub ineval {
  (exists $ENV{MOD_PERL} ? 0 : $^S) || _longmess() =~ /eval [\{\']/m
}

sub die {
  my ($arg) = @_;
  realdie @_ if ineval;
  if (!ref($arg)) {
    $arg = join("", @_);
    my($file,$line,$id) = id(1);
    $arg .= " at $file line $line." unless $arg=~/\n$/;
    &fatalsToBrowser($arg) if $WRAP;
    if (($arg =~ /\n$/) || !exists($ENV{MOD_PERL})) {
      my $stamp = stamp;
      $arg=~s/^/$stamp/gm;
    }
    if ($arg !~ /\n$/) {
      $arg .= "\n";
    }
  }
  realdie $arg;
}

sub set_message {
    $CGI::Carp::CUSTOM_MSG = shift;
    return $CGI::Carp::CUSTOM_MSG;
}

sub confess { CGI::Carp::die Carp::longmess @_; }
sub croak   { CGI::Carp::die Carp::shortmess @_; }
sub carp    { CGI::Carp::warn Carp::shortmess @_; }
sub cluck   { CGI::Carp::warn Carp::longmess @_; }

# We have to be ready to accept a filehandle as a reference
# or a string.
sub carpout {
    my($in) = @_;
    my($no) = fileno(to_filehandle($in));
    realdie("Invalid filehandle $in\n") unless defined $no;
    
    open(SAVEERR, ">&STDERR");
    open(STDERR, ">&$no") or 
        ( print SAVEERR "Unable to redirect STDERR: $!\n" and exit(1) );
}

sub warningsToBrowser {
    $EMIT_WARNINGS = @_ ? shift : 1;
    _warn(shift @WARNINGS) while $EMIT_WARNINGS and @WARNINGS;
}

# headers
sub fatalsToBrowser {
  my($msg) = @_;
  $msg=~s/&/&amp;/g;
  $msg=~s/>/&gt;/g;
  $msg=~s/</&lt;/g;
  $msg=~s/\"/&quot;/g;
  my($wm) = $ENV{SERVER_ADMIN} ? 
    qq[the webmaster (<a href="mailto:$ENV{SERVER_ADMIN}">$ENV{SERVER_ADMIN}</a>)] :
      "this site's webmaster";
  my ($outer_message) = <<END;
For help, please send mail to $wm, giving this error message 
and the time and date of the error.
END
  ;
  my $mod_perl = exists $ENV{MOD_PERL};

  warningsToBrowser(1);    # emit warnings before dying

  if ($CUSTOM_MSG) {
    if (ref($CUSTOM_MSG) eq 'CODE') {
      print STDOUT "Content-type: text/html\n\n" 
        unless $mod_perl;
      &$CUSTOM_MSG($msg); # nicer to perl 5.003 users
      return;
    } else {
      $outer_message = $CUSTOM_MSG;
    }
  }

  my $mess = <<END;
<h1>Software error:</h1>
<pre>$msg</pre>
<p>
$outer_message
</p>
END
  ;

  if ($mod_perl) {
    require mod_perl;
    if ($mod_perl::VERSION >= 1.99) {
      $mod_perl = 2;
      require Apache::RequestRec;
      require Apache::RequestIO;
      require Apache::RequestUtil;
      require APR::Pool;
      require ModPerl::Util;
      require Apache::Response;
    }
    my $r = Apache->request;
    # If bytes have already been sent, then
    # we print the message out directly.
    # Otherwise we make a custom error
    # handler to produce the doc for us.
    if ($r->bytes_sent) {
      $r->print($mess);
      $mod_perl == 2 ? ModPerl::Util::exit(0) : $r->exit;
    } else {
      # MSIE won't display a custom 500 response unless it is >512 bytes!
      if ($ENV{HTTP_USER_AGENT} =~ /MSIE/) {
        $mess = "<!-- " . (' ' x 513) . " -->\n$mess";
      }
      $r->custom_response(500,$mess);
    }
  } else {
    if (eval{tell STDOUT}) {
        print STDOUT $mess;
    }
    else {
        print STDOUT "Content-type: text/html\n\n";
        print STDOUT $mess;
    }
  }
}

# Cut and paste from CGI.pm so that we don't have the overhead of
# always loading the entire CGI module.
sub to_filehandle {
    my $thingy = shift;
    return undef unless $thingy;
    return $thingy if UNIVERSAL::isa($thingy,'GLOB');
    return $thingy if UNIVERSAL::isa($thingy,'FileHandle');
    if (!ref($thingy)) {
        my $caller = 1;
        while (my $package = caller($caller++)) {
            my($tmp) = $thingy=~/[\':]/ ? $thingy : "$package\:\:$thingy"; 
            return $tmp if defined(fileno($tmp));
        }
    }
    return undef;
}

1;
1	package CGI::Carp;
2
3	=head1 NAME
4
5	B<CGI::Carp> - CGI routines for writing to the HTTPD (or other) error log
6
7	=head1 SYNOPSIS
8
9	use CGI::Carp;
10
11	croak "We're outta here!";
12	confess "It was my fault: $!";
13	carp "It was your fault!";
14	warn "I'm confused";
15	die "I'm dying.\n";
16
17	use CGI::Carp qw(cluck);
18	cluck "I wouldn't do that if I were you";
19
20	use CGI::Carp qw(fatalsToBrowser);
21	die "Fatal error messages are now sent to browser";
22
23	=head1 DESCRIPTION
24
25	CGI scripts have a nasty habit of leaving warning messages in the error
26	logs that are neither time stamped nor fully identified. Tracking down
27	the script that caused the error is a pain. This fixes that. Replace
28	the usual
29
30	use Carp;
31
32	with
33
34	use CGI::Carp
35
36	And the standard warn(), die (), croak(), confess() and carp() calls
37	will automagically be replaced with functions that write out nicely
38	time-stamped messages to the HTTP server error log.
39
40	For example:
41
42	[Fri Nov 17 21:40:43 1995] test.pl: I'm confused at test.pl line 3.
43	[Fri Nov 17 21:40:43 1995] test.pl: Got an error message: Permission denied.
44	[Fri Nov 17 21:40:43 1995] test.pl: I'm dying.
45
46	=head1 REDIRECTING ERROR MESSAGES
47
48	By default, error messages are sent to STDERR. Most HTTPD servers
49	direct STDERR to the server's error log. Some applications may wish
50	to keep private error logs, distinct from the server's error log, or
51	they may wish to direct error messages to STDOUT so that the browser
52	will receive them.
53
54	The C<carpout()> function is provided for this purpose. Since
55	carpout() is not exported by default, you must import it explicitly by
56	saying
57
58	use CGI::Carp qw(carpout);
59
60	The carpout() function requires one argument, which should be a
61	reference to an open filehandle for writing errors. It should be
62	called in a C<BEGIN> block at the top of the CGI application so that
63	compiler errors will be caught. Example:
64
65	BEGIN {
66	use CGI::Carp qw(carpout);
67	open(LOG, ">>/usr/local/cgi-logs/mycgi-log") or
68	die("Unable to open mycgi-log: $!\n");
69	carpout(LOG);
70	}
71
72	carpout() does not handle file locking on the log for you at this point.
73
74	The real STDERR is not closed -- it is moved to CGI::Carp::SAVEERR. Some
75	servers, when dealing with CGI scripts, close their connection to the
76	browser when the script closes STDOUT and STDERR. CGI::Carp::SAVEERR is there to
77	prevent this from happening prematurely.
78
79	You can pass filehandles to carpout() in a variety of ways. The "correct"
80	way according to Tom Christiansen is to pass a reference to a filehandle
81	GLOB:
82
83	carpout(\*LOG);
84
85	This looks weird to mere mortals however, so the following syntaxes are
86	accepted as well:
87
88	carpout(LOG);
89	carpout(main::LOG);
90	carpout(main'LOG);
91	carpout(\LOG);
92	carpout(\'main::LOG');
93
94	... and so on
95
96	FileHandle and other objects work as well.
97
98	Use of carpout() is not great for performance, so it is recommended
99	for debugging purposes or for moderate-use applications. A future
100	version of this module may delay redirecting STDERR until one of the
101	CGI::Carp methods is called to prevent the performance hit.
102
103	=head1 MAKING PERL ERRORS APPEAR IN THE BROWSER WINDOW
104
105	If you want to send fatal (die, confess) errors to the browser, ask to
106	import the special "fatalsToBrowser" subroutine:
107
108	use CGI::Carp qw(fatalsToBrowser);
109	die "Bad error here";
110
111	Fatal errors will now be echoed to the browser as well as to the log. CGI::Carp
112	arranges to send a minimal HTTP header to the browser so that even errors that
113	occur in the early compile phase will be seen.
114	Nonfatal errors will still be directed to the log file only (unless redirected
115	with carpout).
116
117	=head2 Changing the default message
118
119	By default, the software error message is followed by a note to
120	contact the Webmaster by e-mail with the time and date of the error.
121	If this message is not to your liking, you can change it using the
122	set_message() routine. This is not imported by default; you should
123	import it on the use() line:
124
125	use CGI::Carp qw(fatalsToBrowser set_message);
126	set_message("It's not a bug, it's a feature!");
127
128	You may also pass in a code reference in order to create a custom
129	error message. At run time, your code will be called with the text
130	of the error message that caused the script to die. Example:
131
132	use CGI::Carp qw(fatalsToBrowser set_message);
133	BEGIN {
134	sub handle_errors {
135	my $msg = shift;
136	print "<h1>Oh gosh</h1>";
137	print "<p>Got an error: $msg</p>";
138	}
139	set_message(\&handle_errors);
140	}
141
142	In order to correctly intercept compile-time errors, you should call
143	set_message() from within a BEGIN{} block.
144
145	=head1 MAKING WARNINGS APPEAR AS HTML COMMENTS
146
147	It is now also possible to make non-fatal errors appear as HTML
148	comments embedded in the output of your program. To enable this
149	feature, export the new "warningsToBrowser" subroutine. Since sending
150	warnings to the browser before the HTTP headers have been sent would
151	cause an error, any warnings are stored in an internal buffer until
152	you call the warningsToBrowser() subroutine with a true argument:
153
154	use CGI::Carp qw(fatalsToBrowser warningsToBrowser);
155	use CGI qw(:standard);
156	print header();
157	warningsToBrowser(1);
158
159	You may also give a false argument to warningsToBrowser() to prevent
160	warnings from being sent to the browser while you are printing some
161	content where HTML comments are not allowed:
162
163	warningsToBrowser(0); # disable warnings
164	print "<script type=\"text/javascript\"><!--\n";
165	print_some_javascript_code();
166	print "//--></script>\n";
167	warningsToBrowser(1); # re-enable warnings
168
169	Note: In this respect warningsToBrowser() differs fundamentally from
170	fatalsToBrowser(), which you should never call yourself!
171
172	=head1 OVERRIDING THE NAME OF THE PROGRAM
173
174	CGI::Carp includes the name of the program that generated the error or
175	warning in the messages written to the log and the browser window.
176	Sometimes, Perl can get confused about what the actual name of the
177	executed program was. In these cases, you can override the program
178	name that CGI::Carp will use for all messages.
179
180	The quick way to do that is to tell CGI::Carp the name of the program
181	in its use statement. You can do that by adding
182	"name=cgi_carp_log_name" to your "use" statement. For example:
183
184	use CGI::Carp qw(name=cgi_carp_log_name);
185
186	. If you want to change the program name partway through the program,
187	you can use the C<set_progname()> function instead. It is not
188	exported by default, you must import it explicitly by saying
189
190	use CGI::Carp qw(set_progname);
191
192	Once you've done that, you can change the logged name of the program
193	at any time by calling
194
195	set_progname(new_program_name);
196
197	You can set the program back to the default by calling
198
199	set_progname(undef);
200
201	Note that this override doesn't happen until after the program has
202	compiled, so any compile-time errors will still show up with the
203	non-overridden program name
204
205	=head1 CHANGE LOG
206
207	1.05 carpout() added and minor corrections by Marc Hedlund
208	<hedlund@best.com> on 11/26/95.
209
210	1.06 fatalsToBrowser() no longer aborts for fatal errors within
211	eval() statements.
212
213	1.08 set_message() added and carpout() expanded to allow for FileHandle
214	objects.
215
216	1.09 set_message() now allows users to pass a code REFERENCE for
217	really custom error messages. croak and carp are now
218	exported by default. Thanks to Gunther Birznieks for the
219	patches.
220
221	1.10 Patch from Chris Dean (ctdean@cogit.com) to allow
222	module to run correctly under mod_perl.
223
224	1.11 Changed order of > and < escapes.
225
226	1.12 Changed die() on line 217 to CORE::die to avoid B<-w> warning.
227
228	1.13 Added cluck() to make the module orthogonal with Carp.
229	More mod_perl related fixes.
230
231	1.20 Patch from Ilmari Karonen (perl@itz.pp.sci.fi): Added
232	warningsToBrowser(). Replaced <CODE> tags with <PRE> in
233	fatalsToBrowser() output.
234
235	1.23 ineval() now checks both $^S and inspects the message for the "eval" pattern
236	(hack alert!) in order to accomodate various combinations of Perl and
237	mod_perl.
238
239	1.24 Patch from Scott Gifford (sgifford@suspectclass.com): Add support
240	for overriding program name.
241
242	1.26 Replaced CORE::GLOBAL::die with the evil $SIG{__DIE__} because the
243	former isn't working in some people's hands. There is no such thing
244	as reliable exception handling in Perl.
245
246	=head1 AUTHORS
247
248	Copyright 1995-2002, Lincoln D. Stein. All rights reserved.
249
250	This library is free software; you can redistribute it and/or modify
251	it under the same terms as Perl itself.
252
253	Address bug reports and comments to: lstein@cshl.org
254
255	=head1 SEE ALSO
256
257	Carp, CGI::Base, CGI::BasePlus, CGI::Request, CGI::MiniSvr, CGI::Form,
258	CGI::Response
259	if (defined($CGI::Carp::PROGNAME))
260	{
261	$file = $CGI::Carp::PROGNAME;
262	}
263
264	=cut
265
266	require 5.000;
267	use Exporter;
268	#use Carp;
269	BEGIN {
270	require Carp;
271	*CORE::GLOBAL::die = \&CGI::Carp::die;
272	}
273
274	use File::Spec;
275
276	@ISA = qw(Exporter);
277	@EXPORT = qw(confess croak carp);
278	@EXPORT_OK = qw(carpout fatalsToBrowser warningsToBrowser wrap set_message set_progname cluck ^name= die);
279
280	$main::SIG{__WARN__}=\&CGI::Carp::warn;
281
282	$CGI::Carp::VERSION = '1.26';
283	$CGI::Carp::CUSTOM_MSG = undef;
284
285
286	# fancy import routine detects and handles 'errorWrap' specially.
287	sub import {
288	my $pkg = shift;
289	my(%routines);
290	my(@name);
291
292	if (@name=grep(/^name=/,@_))
293	{
294	my($n) = (split(/=/,$name[0]))[1];
295	set_progname($n);
296	@_=grep(!/^name=/,@_);
297	}
298
299	grep($routines{$_}++,@_,@EXPORT);
300	$WRAP++ if $routines{'fatalsToBrowser'} \|\| $routines{'wrap'};
301	$WARN++ if $routines{'warningsToBrowser'};
302	my($oldlevel) = $Exporter::ExportLevel;
303	$Exporter::ExportLevel = 1;
304	Exporter::import($pkg,keys %routines);
305	$Exporter::ExportLevel = $oldlevel;
306	$main::SIG{__DIE__} =\&CGI::Carp::die if $routines{'fatalsToBrowser'};
307	# $pkg->export('CORE::GLOBAL','die');
308	}
309
310	# These are the originals
311	sub realwarn { CORE::warn(@_); }
312	sub realdie { CORE::die(@_); }
313
314	sub id {
315	my $level = shift;
316	my($pack,$file,$line,$sub) = caller($level);
317	my($dev,$dirs,$id) = File::Spec->splitpath($file);
318	return ($file,$line,$id);
319	}
320
321	sub stamp {
322	my $time = scalar(localtime);
323	my $frame = 0;
324	my ($id,$pack,$file,$dev,$dirs);
325	if (defined($CGI::Carp::PROGNAME)) {
326	$id = $CGI::Carp::PROGNAME;
327	} else {
328	do {
329	$id = $file;
330	($pack,$file) = caller($frame++);
331	} until !$file;
332	}
333	($dev,$dirs,$id) = File::Spec->splitpath($id);
334	return "[$time] $id: ";
335	}
336
337	sub set_progname {
338	$CGI::Carp::PROGNAME = shift;
339	return $CGI::Carp::PROGNAME;
340	}
341
342
343	sub warn {
344	my $message = shift;
345	my($file,$line,$id) = id(1);
346	$message .= " at $file line $line.\n" unless $message=~/\n$/;
347	_warn($message) if $WARN;
348	my $stamp = stamp;
349	$message=~s/^/$stamp/gm;
350	realwarn $message;
351	}
352
353	sub _warn {
354	my $msg = shift;
355	if ($EMIT_WARNINGS) {
356	# We need to mangle the message a bit to make it a valid HTML
357	# comment. This is done by substituting similar-looking ISO
358	# 8859-1 characters for <, > and -. This is a hack.
359	$msg =~ tr/<>-/\253\273\255/;
360	chomp $msg;
361	print STDOUT "<!-- warning: $msg -->\n";
362	} else {
363	push @WARNINGS, $msg;
364	}
365	}
366
367
368	# The mod_perl package Apache::Registry loads CGI programs by calling
369	# eval. These evals don't count when looking at the stack backtrace.
370	sub _longmess {
371	my $message = Carp::longmess();
372	$message =~ s,eval[^\n]+(ModPerl\|Apache)/Registry\w\.pm.,,s
373	if exists $ENV{MOD_PERL};
374	return $message;
375	}
376
377	sub ineval {
378	(exists $ENV{MOD_PERL} ? 0 : $^S) \|\| _longmess() =~ /eval [\{\']/m
379	}
380
381	sub die {
382	my ($arg) = @_;
383	realdie @_ if ineval;
384	if (!ref($arg)) {
385	$arg = join("", @_);
386	my($file,$line,$id) = id(1);
387	$arg .= " at $file line $line." unless $arg=~/\n$/;
388	&fatalsToBrowser($arg) if $WRAP;
389	if (($arg =~ /\n$/) \|\| !exists($ENV{MOD_PERL})) {
390	my $stamp = stamp;
391	$arg=~s/^/$stamp/gm;
392	}
393	if ($arg !~ /\n$/) {
394	$arg .= "\n";
395	}
396	}
397	realdie $arg;
398	}
399
400	sub set_message {
401	$CGI::Carp::CUSTOM_MSG = shift;
402	return $CGI::Carp::CUSTOM_MSG;
403	}
404
405	sub confess { CGI::Carp::die Carp::longmess @_; }
406	sub croak { CGI::Carp::die Carp::shortmess @_; }
407	sub carp { CGI::Carp::warn Carp::shortmess @_; }
408	sub cluck { CGI::Carp::warn Carp::longmess @_; }
409
410	# We have to be ready to accept a filehandle as a reference
411	# or a string.
412	sub carpout {
413	my($in) = @_;
414	my($no) = fileno(to_filehandle($in));
415	realdie("Invalid filehandle $in\n") unless defined $no;
416
417	open(SAVEERR, ">&STDERR");
418	open(STDERR, ">&$no") or
419	( print SAVEERR "Unable to redirect STDERR: $!\n" and exit(1) );
420	}
421
422	sub warningsToBrowser {
423	$EMIT_WARNINGS = @_ ? shift : 1;
424	_warn(shift @WARNINGS) while $EMIT_WARNINGS and @WARNINGS;
425	}
426
427	# headers
428	sub fatalsToBrowser {
429	my($msg) = @_;
430	$msg=~s/&/&/g;
431	$msg=~s/>/>/g;
432	$msg=~s/</</g;
433	$msg=~s/\"/"/g;
434	my($wm) = $ENV{SERVER_ADMIN} ?
435	qq[the webmaster (<a href="mailto:$ENV{SERVER_ADMIN}">$ENV{SERVER_ADMIN}</a>)] :
436	"this site's webmaster";
437	my ($outer_message) = <<END;
438	For help, please send mail to $wm, giving this error message
439	and the time and date of the error.
440	END
441	;
442	my $mod_perl = exists $ENV{MOD_PERL};
443
444	warningsToBrowser(1); # emit warnings before dying
445
446	if ($CUSTOM_MSG) {
447	if (ref($CUSTOM_MSG) eq 'CODE') {
448	print STDOUT "Content-type: text/html\n\n"
449	unless $mod_perl;
450	&$CUSTOM_MSG($msg); # nicer to perl 5.003 users
451	return;
452	} else {
453	$outer_message = $CUSTOM_MSG;
454	}
455	}
456
457	my $mess = <<END;
458	<h1>Software error:</h1>
459	<pre>$msg</pre>
460	<p>
461	$outer_message
462	</p>
463	END
464	;
465
466	if ($mod_perl) {
467	require mod_perl;
468	if ($mod_perl::VERSION >= 1.99) {
469	$mod_perl = 2;
470	require Apache::RequestRec;
471	require Apache::RequestIO;
472	require Apache::RequestUtil;
473	require APR::Pool;
474	require ModPerl::Util;
475	require Apache::Response;
476	}
477	my $r = Apache->request;
478	# If bytes have already been sent, then
479	# we print the message out directly.
480	# Otherwise we make a custom error
481	# handler to produce the doc for us.
482	if ($r->bytes_sent) {
483	$r->print($mess);
484	$mod_perl == 2 ? ModPerl::Util::exit(0) : $r->exit;
485	} else {
486	# MSIE won't display a custom 500 response unless it is >512 bytes!
487	if ($ENV{HTTP_USER_AGENT} =~ /MSIE/) {
488	$mess = "<!-- " . (' ' x 513) . " -->\n$mess";
489	}
490	$r->custom_response(500,$mess);
491	}
492	} else {
493	if (eval{tell STDOUT}) {
494	print STDOUT $mess;
495	}
496	else {
497	print STDOUT "Content-type: text/html\n\n";
498	print STDOUT $mess;
499	}
500	}
501	}
502
503	# Cut and paste from CGI.pm so that we don't have the overhead of
504	# always loading the entire CGI module.
505	sub to_filehandle {
506	my $thingy = shift;
507	return undef unless $thingy;
508	return $thingy if UNIVERSAL::isa($thingy,'GLOB');
509	return $thingy if UNIVERSAL::isa($thingy,'FileHandle');
510	if (!ref($thingy)) {
511	my $caller = 1;
512	while (my $package = caller($caller++)) {
513	my($tmp) = $thingy=~/[\':]/ ? $thingy : "$package\:\:$thingy";
514	return $tmp if defined(fileno($tmp));
515	}
516	}
517	return undef;
518	}
519
520	1;