[p5sagit/p5-mst-13.2.git] / 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).

Note that fatalsToBrowser does B<not> work with mod_perl version 2.0
and higher.

=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 accommodate 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.

1.27 Replaced tell STDOUT with bytes=tell STDOUT.

=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    = '1.29';
$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|Dispatch)\w*\.pm.*,,s
        if exists $ENV{MOD_PERL};
    return $message;
}

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

sub die {
  my ($arg,@rest) = @_;
  realdie ($arg,@rest) if ineval();

  if (!ref($arg)) {
    $arg = join("", ($arg,@rest));
    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};

  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) {
    my $r;
    if ($ENV{MOD_PERL_API_VERSION} && $ENV{MOD_PERL_API_VERSION} == 2) {
      $mod_perl = 2;
      require Apache2::RequestRec;
      require Apache2::RequestIO;
      require Apache2::RequestUtil;
      require APR::Pool;
      require ModPerl::Util;
      require Apache2::Response;
      $r = Apache2::RequestUtil->request;
    }
    else {
      $r = Apache->request;
    }
    # If bytes have already been sent, then
    # we print the message out directly.
    # Otherwise we make a custom error
    # handler to produce the doc for us.
    if ($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 {
    my $bytes_written = eval{tell STDOUT};
    if (defined $bytes_written && $bytes_written > 0) {
        print STDOUT $mess;
    }
    else {
        print STDOUT "Content-type: text/html\n\n";
        print STDOUT $mess;
    }
  }

  warningsToBrowser(1);    # emit warnings before dying
}

# 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;
Commit	Line	Data
54310121	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
71f3e297	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
54310121	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
ba056755	74	The real STDERR is not closed -- it is moved to CGI::Carp::SAVEERR. Some
54310121	75	servers, when dealing with CGI scripts, close their connection to the
ba056755	76	browser when the script closes STDOUT and STDERR. CGI::Carp::SAVEERR is there to
54310121	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
424ec8fa	96	FileHandle and other objects work as well.
424ec8fa	97
54310121	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
55b5d700	105	If you want to send fatal (die, confess) errors to the browser, ask to
54310121	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
55b5d700	117	Note that fatalsToBrowser does B<not> work with mod_perl version 2.0
	118	and higher.
	119
424ec8fa	120	=head2 Changing the default message
	121
	122	By default, the software error message is followed by a note to
	123	contact the Webmaster by e-mail with the time and date of the error.
	124	If this message is not to your liking, you can change it using the
	125	set_message() routine. This is not imported by default; you should
	126	import it on the use() line:
	127
	128	use CGI::Carp qw(fatalsToBrowser set_message);
	129	set_message("It's not a bug, it's a feature!");
	130
	131	You may also pass in a code reference in order to create a custom
	132	error message. At run time, your code will be called with the text
	133	of the error message that caused the script to die. Example:
	134
	135	use CGI::Carp qw(fatalsToBrowser set_message);
	136	BEGIN {
	137	sub handle_errors {
	138	my $msg = shift;
	139	print "<h1>Oh gosh</h1>";
b2d0d414	140	print "<p>Got an error: $msg</p>";
424ec8fa	141	}
	142	set_message(\&handle_errors);
	143	}
	144
	145	In order to correctly intercept compile-time errors, you should call
	146	set_message() from within a BEGIN{} block.
	147
6b4ac661	148	=head1 MAKING WARNINGS APPEAR AS HTML COMMENTS
	149
	150	It is now also possible to make non-fatal errors appear as HTML
	151	comments embedded in the output of your program. To enable this
	152	feature, export the new "warningsToBrowser" subroutine. Since sending
	153	warnings to the browser before the HTTP headers have been sent would
	154	cause an error, any warnings are stored in an internal buffer until
	155	you call the warningsToBrowser() subroutine with a true argument:
	156
	157	use CGI::Carp qw(fatalsToBrowser warningsToBrowser);
	158	use CGI qw(:standard);
	159	print header();
	160	warningsToBrowser(1);
	161
	162	You may also give a false argument to warningsToBrowser() to prevent
	163	warnings from being sent to the browser while you are printing some
	164	content where HTML comments are not allowed:
	165
	166	warningsToBrowser(0); # disable warnings
b2d0d414	167	print "<script type=\"text/javascript\"><!--\n";
6b4ac661	168	print_some_javascript_code();
b2d0d414	169	print "//--></script>\n";
6b4ac661	170	warningsToBrowser(1); # re-enable warnings
	171
	172	Note: In this respect warningsToBrowser() differs fundamentally from
	173	fatalsToBrowser(), which you should never call yourself!
	174
188ba755	175	=head1 OVERRIDING THE NAME OF THE PROGRAM
	176
	177	CGI::Carp includes the name of the program that generated the error or
	178	warning in the messages written to the log and the browser window.
	179	Sometimes, Perl can get confused about what the actual name of the
	180	executed program was. In these cases, you can override the program
	181	name that CGI::Carp will use for all messages.
	182
	183	The quick way to do that is to tell CGI::Carp the name of the program
	184	in its use statement. You can do that by adding
	185	"name=cgi_carp_log_name" to your "use" statement. For example:
	186
	187	use CGI::Carp qw(name=cgi_carp_log_name);
	188
	189	. If you want to change the program name partway through the program,
	190	you can use the C<set_progname()> function instead. It is not
	191	exported by default, you must import it explicitly by saying
	192
	193	use CGI::Carp qw(set_progname);
	194
	195	Once you've done that, you can change the logged name of the program
	196	at any time by calling
	197
	198	set_progname(new_program_name);
	199
	200	You can set the program back to the default by calling
	201
	202	set_progname(undef);
	203
	204	Note that this override doesn't happen until after the program has
	205	compiled, so any compile-time errors will still show up with the
	206	non-overridden program name
	207
54310121	208	=head1 CHANGE LOG
	209
	210	1.05 carpout() added and minor corrections by Marc Hedlund
	211	<hedlund@best.com> on 11/26/95.
	212
	213	1.06 fatalsToBrowser() no longer aborts for fatal errors within
	214	eval() statements.
	215
424ec8fa	216	1.08 set_message() added and carpout() expanded to allow for FileHandle
	217	objects.
	218
	219	1.09 set_message() now allows users to pass a code REFERENCE for
	220	really custom error messages. croak and carp are now
	221	exported by default. Thanks to Gunther Birznieks for the
	222	patches.
	223
	224	1.10 Patch from Chris Dean (ctdean@cogit.com) to allow
	225	module to run correctly under mod_perl.
	226
71f3e297	227	1.11 Changed order of > and < escapes.
	228
	229	1.12 Changed die() on line 217 to CORE::die to avoid B<-w> warning.
	230
	231	1.13 Added cluck() to make the module orthogonal with Carp.
6b4ac661	232	More mod_perl related fixes.
	233
	234	1.20 Patch from Ilmari Karonen (perl@itz.pp.sci.fi): Added
	235	warningsToBrowser(). Replaced <CODE> tags with <PRE> in
	236	fatalsToBrowser() output.
71f3e297	237
b2d0d414	238	1.23 ineval() now checks both $^S and inspects the message for the "eval" pattern
3c4b39be	239	(hack alert!) in order to accommodate various combinations of Perl and
b2d0d414	240	mod_perl.
b2d0d414	241
188ba755	242	1.24 Patch from Scott Gifford (sgifford@suspectclass.com): Add support
	243	for overriding program name.
	244
1c87da1d	245	1.26 Replaced CORE::GLOBAL::die with the evil $SIG{__DIE__} because the
	246	former isn't working in some people's hands. There is no such thing
	247	as reliable exception handling in Perl.
	248
2ed511ec	249	1.27 Replaced tell STDOUT with bytes=tell STDOUT.
2ed511ec	250
54310121	251	=head1 AUTHORS
54310121	252
b2d0d414	253	Copyright 1995-2002, Lincoln D. Stein. All rights reserved.
71f3e297	254
	255	This library is free software; you can redistribute it and/or modify
	256	it under the same terms as Perl itself.
54310121	257
71f3e297	258	Address bug reports and comments to: lstein@cshl.org
54310121	259
	260	=head1 SEE ALSO
	261
	262	Carp, CGI::Base, CGI::BasePlus, CGI::Request, CGI::MiniSvr, CGI::Form,
	263	CGI::Response
188ba755	264	if (defined($CGI::Carp::PROGNAME))
	265	{
	266	$file = $CGI::Carp::PROGNAME;
	267	}
54310121	268
	269	=cut
	270
	271	require 5.000;
	272	use Exporter;
3acbd4f5	273	#use Carp;
1c87da1d	274	BEGIN {
	275	require Carp;
	276	*CORE::GLOBAL::die = \&CGI::Carp::die;
	277	}
	278
7f16a916	279	use File::Spec;
54310121	280
	281	@ISA = qw(Exporter);
	282	@EXPORT = qw(confess croak carp);
1c87da1d	283	@EXPORT_OK = qw(carpout fatalsToBrowser warningsToBrowser wrap set_message set_progname cluck ^name= die);
3538e1d5	284
54310121	285	$main::SIG{__WARN__}=\&CGI::Carp::warn;
1c87da1d	286
29ddc2a4	287	$CGI::Carp::VERSION = '1.29';
424ec8fa	288	$CGI::Carp::CUSTOM_MSG = undef;
54310121	289
1c87da1d	290
54310121	291	# fancy import routine detects and handles 'errorWrap' specially.
	292	sub import {
	293	my $pkg = shift;
	294	my(%routines);
188ba755	295	my(@name);
188ba755	296	if (@name=grep(/^name=/,@_))
	297	{
	298	my($n) = (split(/=/,$name[0]))[1];
	299	set_progname($n);
	300	@_=grep(!/^name=/,@_);
	301	}
	302
424ec8fa	303	grep($routines{$_}++,@_,@EXPORT);
424ec8fa	304	$WRAP++ if $routines{'fatalsToBrowser'} \|\| $routines{'wrap'};
6b4ac661	305	$WARN++ if $routines{'warningsToBrowser'};
54310121	306	my($oldlevel) = $Exporter::ExportLevel;
	307	$Exporter::ExportLevel = 1;
	308	Exporter::import($pkg,keys %routines);
	309	$Exporter::ExportLevel = $oldlevel;
1c87da1d	310	$main::SIG{__DIE__} =\&CGI::Carp::die if $routines{'fatalsToBrowser'};
1c87da1d	311	# $pkg->export('CORE::GLOBAL','die');
54310121	312	}
	313
	314	# These are the originals
9014bb8e	315	sub realwarn { CORE::warn(@_); }
9014bb8e	316	sub realdie { CORE::die(@_); }
54310121	317
	318	sub id {
	319	my $level = shift;
	320	my($pack,$file,$line,$sub) = caller($level);
7f16a916	321	my($dev,$dirs,$id) = File::Spec->splitpath($file);
54310121	322	return ($file,$line,$id);
	323	}
	324
	325	sub stamp {
	326	my $time = scalar(localtime);
	327	my $frame = 0;
ac734d8b	328	my ($id,$pack,$file,$dev,$dirs);
188ba755	329	if (defined($CGI::Carp::PROGNAME)) {
	330	$id = $CGI::Carp::PROGNAME;
	331	} else {
	332	do {
	333	$id = $file;
	334	($pack,$file) = caller($frame++);
	335	} until !$file;
	336	}
7f16a916	337	($dev,$dirs,$id) = File::Spec->splitpath($id);
54310121	338	return "[$time] $id: ";
	339	}
	340
188ba755	341	sub set_progname {
	342	$CGI::Carp::PROGNAME = shift;
	343	return $CGI::Carp::PROGNAME;
	344	}
	345
	346
54310121	347	sub warn {
	348	my $message = shift;
	349	my($file,$line,$id) = id(1);
	350	$message .= " at $file line $line.\n" unless $message=~/\n$/;
6b4ac661	351	_warn($message) if $WARN;
54310121	352	my $stamp = stamp;
	353	$message=~s/^/$stamp/gm;
	354	realwarn $message;
	355	}
	356
6b4ac661	357	sub _warn {
	358	my $msg = shift;
	359	if ($EMIT_WARNINGS) {
	360	# We need to mangle the message a bit to make it a valid HTML
	361	# comment. This is done by substituting similar-looking ISO
	362	# 8859-1 characters for <, > and -. This is a hack.
	363	$msg =~ tr/<>-/\253\273\255/;
	364	chomp $msg;
	365	print STDOUT "<!-- warning: $msg -->\n";
	366	} else {
	367	push @WARNINGS, $msg;
	368	}
	369	}
	370
6b4ac661	371
424ec8fa	372	# The mod_perl package Apache::Registry loads CGI programs by calling
	373	# eval. These evals don't count when looking at the stack backtrace.
	374	sub _longmess {
	375	my $message = Carp::longmess();
29ddc2a4	376	$message =~ s,eval[^\n]+(ModPerl\|Apache)/(?:Registry\|Dispatch)\w\.pm.,,s
8f3ccfa2	377	if exists $ENV{MOD_PERL};
	378	return $message;
	379	}
	380
	381	sub ineval {
	382	(exists $ENV{MOD_PERL} ? 0 : $^S) \|\| _longmess() =~ /eval [\{\']/m
424ec8fa	383	}
424ec8fa	384
54310121	385	sub die {
13548fdf	386	my ($arg,@rest) = @_;
	387	realdie ($arg,@rest) if ineval();
	388
8f3ccfa2	389	if (!ref($arg)) {
13548fdf	390	$arg = join("", ($arg,@rest));
8f3ccfa2	391	my($file,$line,$id) = id(1);
	392	$arg .= " at $file line $line." unless $arg=~/\n$/;
	393	&fatalsToBrowser($arg) if $WRAP;
	394	if (($arg =~ /\n$/) \|\| !exists($ENV{MOD_PERL})) {
	395	my $stamp = stamp;
	396	$arg=~s/^/$stamp/gm;
	397	}
	398	if ($arg !~ /\n$/) {
	399	$arg .= "\n";
	400	}
	401	}
	402	realdie $arg;
54310121	403	}
54310121	404
424ec8fa	405	sub set_message {
	406	$CGI::Carp::CUSTOM_MSG = shift;
	407	return $CGI::Carp::CUSTOM_MSG;
	408	}
	409
2371fea9	410	sub confess { CGI::Carp::die Carp::longmess @_; }
	411	sub croak { CGI::Carp::die Carp::shortmess @_; }
	412	sub carp { CGI::Carp::warn Carp::shortmess @_; }
	413	sub cluck { CGI::Carp::warn Carp::longmess @_; }
54310121	414
	415	# We have to be ready to accept a filehandle as a reference
	416	# or a string.
	417	sub carpout {
	418	my($in) = @_;
424ec8fa	419	my($no) = fileno(to_filehandle($in));
71f3e297	420	realdie("Invalid filehandle $in\n") unless defined $no;
54310121	421
	422	open(SAVEERR, ">&STDERR");
	423	open(STDERR, ">&$no") or
	424	( print SAVEERR "Unable to redirect STDERR: $!\n" and exit(1) );
	425	}
	426
6b4ac661	427	sub warningsToBrowser {
	428	$EMIT_WARNINGS = @_ ? shift : 1;
	429	_warn(shift @WARNINGS) while $EMIT_WARNINGS and @WARNINGS;
	430	}
	431
54310121	432	# headers
54310121	433	sub fatalsToBrowser {
8f3ccfa2	434	my($msg) = @_;
	435	$msg=~s/&/&/g;
	436	$msg=~s/>/>/g;
	437	$msg=~s/</</g;
	438	$msg=~s/\"/"/g;
	439	my($wm) = $ENV{SERVER_ADMIN} ?
	440	qq[the webmaster (<a href="mailto:$ENV{SERVER_ADMIN}">$ENV{SERVER_ADMIN}</a>)] :
	441	"this site's webmaster";
	442	my ($outer_message) = <<END;
424ec8fa	443	For help, please send mail to $wm, giving this error message
	444	and the time and date of the error.
	445	END
8f3ccfa2	446	;
8f3ccfa2	447	my $mod_perl = exists $ENV{MOD_PERL};
8f3ccfa2	448
8f3ccfa2	449	if ($CUSTOM_MSG) {
8f3ccfa2	450	if (ref($CUSTOM_MSG) eq 'CODE') {
0c45d622	451	print STDOUT "Content-type: text/html\n\n"
0c45d622	452	unless $mod_perl;
8f3ccfa2	453	&$CUSTOM_MSG($msg); # nicer to perl 5.003 users
	454	return;
	455	} else {
	456	$outer_message = $CUSTOM_MSG;
424ec8fa	457	}
8f3ccfa2	458	}
1c87da1d	459
8f3ccfa2	460	my $mess = <<END;
b2d0d414	461	<h1>Software error:</h1>
	462	<pre>$msg</pre>
	463	<p>
71f3e297	464	$outer_message
b2d0d414	465	</p>
54310121	466	END
8f3ccfa2	467	;
1c87da1d	468
8f3ccfa2	469	if ($mod_perl) {
741ff09d	470	my $r;
0a9bdad4	471	if ($ENV{MOD_PERL_API_VERSION} && $ENV{MOD_PERL_API_VERSION} == 2) {
8f3ccfa2	472	$mod_perl = 2;
741ff09d	473	require Apache2::RequestRec;
	474	require Apache2::RequestIO;
	475	require Apache2::RequestUtil;
8f3ccfa2	476	require APR::Pool;
8f3ccfa2	477	require ModPerl::Util;
741ff09d	478	require Apache2::Response;
	479	$r = Apache2::RequestUtil->request;
	480	}
	481	else {
	482	$r = Apache->request;
8f3ccfa2	483	}
8f3ccfa2	484	# If bytes have already been sent, then
	485	# we print the message out directly.
	486	# Otherwise we make a custom error
	487	# handler to produce the doc for us.
	488	if ($r->bytes_sent) {
	489	$r->print($mess);
	490	$mod_perl == 2 ? ModPerl::Util::exit(0) : $r->exit;
71f3e297	491	} else {
1c87da1d	492	# MSIE won't display a custom 500 response unless it is >512 bytes!
8f3ccfa2	493	if ($ENV{HTTP_USER_AGENT} =~ /MSIE/) {
1c87da1d	494	$mess = "<!-- " . (' ' x 513) . " -->\n$mess";
8f3ccfa2	495	}
1c87da1d	496	$r->custom_response(500,$mess);
71f3e297	497	}
8f3ccfa2	498	} else {
2ed511ec	499	my $bytes_written = eval{tell STDOUT};
2ed511ec	500	if (defined $bytes_written && $bytes_written > 0) {
0c45d622	501	print STDOUT $mess;
	502	}
	503	else {
	504	print STDOUT "Content-type: text/html\n\n";
	505	print STDOUT $mess;
	506	}
8f3ccfa2	507	}
13548fdf	508
13548fdf	509	warningsToBrowser(1); # emit warnings before dying
424ec8fa	510	}
	511
	512	# Cut and paste from CGI.pm so that we don't have the overhead of
	513	# always loading the entire CGI module.
	514	sub to_filehandle {
	515	my $thingy = shift;
	516	return undef unless $thingy;
	517	return $thingy if UNIVERSAL::isa($thingy,'GLOB');
	518	return $thingy if UNIVERSAL::isa($thingy,'FileHandle');
	519	if (!ref($thingy)) {
	520	my $caller = 1;
	521	while (my $package = caller($caller++)) {
	522	my($tmp) = $thingy=~/[\':]/ ? $thingy : "$package\:\:$thingy";
	523	return $tmp if defined(fileno($tmp));
	524	}
	525	}
	526	return undef;
54310121	527	}
	528
	529	1;