in reply to Premature End of Script Headers (was: Re: Newbie error management question) (code)
in thread Newbie error management question

thanks for the suggestion. Can you unstick me from this next one, too? What is the difference between printing headers immediately (as you suggested) and using

$|=1;

to flush the buffers. I thought that this would send the headers (?). Also, if I have a script that takes awhile to run (e.g. complex MySQL statements), sometimes the browser times out. IS there a way to let the browser know "Hold on... I'm coming with your answer" ?

  • Comment on Re: Premature End of Script Headers (was: Re: Newbie error management question) (code)

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Re: Re: Premature End of Script Headers (was: Re: Newbie error management question) (code)
by deprecated (Priest) on May 13, 2001 at 18:35 UTC
    Glad I could be of help.

    I can't really help without seeing your script. $|++ doesnt really "flush the buffers" as much as it tells perl not to hold buffers. I'm happy to offer help, but I cant see what's going wrong with your code without, er, seeing whats wrong with your code. :)

    brother dep.

    --
    Laziness, Impatience, Hubris, and Generosity.

[reply]
      The error reads "error reading the headers", not "Premature end of Script Headers". I have seen both...is there a difference?

      Thanks again for the help. Here is the code in question. Please be merciful: 

      #!/usr/bin/perl -w


# NEEDED Variables
$basedir = "/home/**/**";
$linkscgi = "http://www.foo.cgi";

# use form to get the data
use CGI qw(:standard);
$query = new CGI;

# enable MySQL database
use DBI;
$dsn="DBI:mysql:database=foo";

$client_email = $query->param('email');
chomp($client_email);
$new_url = $query->param('url');
chomp($new_url);
$new_title = $query->param('title');

print "Content-Type: text/html\n\n";
$|++;


$mailprog = "/usr/sbin/sendmail";

$LOC = "ALL"; 

$TRACKER = $ENV{'HTTP_REFERER'};
if (!($TRACKER)) { $TRACKER = $ENV{'REMOTE_ADDR'}; }


####################################
# CHECK Entries

@LINE= split (/"/,$new_url);

$new_url = $LINE[0];

$new_title =~ s/<[^>]*>//g;
$new_title =~ s/\/[^>]*>//g;
$new_title = &convert_bad_chars($new_title);
$new_url = &convert_bad_chars($new_url);
 

if ($new_url eq 'http://' || $new_url !~ /^(f|ht)tp:\/\/(\w|\-)+\.\w+/
+) { 
   &no_url; 
} 
if (!($new_title)) {
   &no_title;
}
if (!($client_email)) {
   &no_emailid;
}

if ($client_email !~ /^[\w\d][\w\d\,\.\-]*\@([\w\d\-]+\.)+([a-zA-Z]{3}
+|[a-zA-Z]{2})$/) {
   &no_emailid;
}

open (FILE, "badurls.txt");
flock (FILE, 2);
@banURL = grep{/$LINE[0]/} <FILE>;
flock (FILE, 8);
close (FILE);
if (@banURL) { &not_allowed($LINE[0]); }

#check against 'bad-email' list
open (FILE, "bademails.txt");
flock (FILE, 2);
@banEMAIL = grep{/$client_email/}<FILE>;
flock (FILE, 8);
close (FILE);
if (@banEMAIL) { &not_allowed($client_email); }

#check to see if code is unique    
    $flag = 1;
    $dbh = DBI->connect($dsn,'foo','foo') or die "Can't connect to MyS
+QL database.";
    while ($flag == 1) {
        $CODE = &gen_code;
        $cursor = $dbh->prepare("SELECT count(*) FROM s_table WHERE ID
+_Code = '$CODE'");
        $cursor->execute();
        while (my $get = $cursor->fetchrow_hashref()) {
            $check = $get->{'count(*)'};
            }
        if ($check==0) { $flag = 0; }
        }    
        $cursor->finish();
        $dbh->disconnect;
        
# Enter MySQL and Add Entry....
    $dbh = DBI->connect($dsn,'foo','foo') or die "Can't connect to MyS
+QL database.";
    while ($flag == 1) {
        $cursor = $dbh->prepare("INSERT INTO s_table (ID_Code,Email,Ur
+l,Title,Section,Location,Tracker,Date)
            VALUES ('$CODE','$client_email','$new_url','$new_title','$
+where','$LOC','$TRACKER',
            NOW())");
        $cursor->execute();
#check to see if entry was accepted
        $cursor = $dbh->prepare("SELECT count(*) FROM s_table WHERE ID
+_Code = '$CODE'");
        $cursor->execute();
        while (my $get = $cursor->fetchrow_hashref()) {
            $check = $get->{'count(*)'};
            }
        if ($check) { $flag = 0; }
        }    
        $cursor->finish();
        $dbh->disconnect;
    
#######
# convert title,url 

$new_title =~ s/\\//g;
$new_url =~ s/\\//g;    
$date= localtime;
    

#Send Email...

 open (MAIL, "|$mailprog -t") || die "Can't open $mailprog!\n";

    print MAIL "To: $client_email\n";
    print MAIL "From: foo\n";   
    print MAIL "Subject: Your entry\n\n";

    print MAIL "Thank you for adding your entry.\n";
    print MAIL "\n----------------------------------------------------
+--\n";
    print MAIL "Your Link:\n\n";

    print MAIL "$new_title\n";

    print MAIL "$new_url\n";
    print MAIL "Section: $where\n\n";
    print MAIL "Submitted on $date\n";
    print MAIL "\n";
    close (MAIL);


print "<html><head><title>Output stuff...</title></head>\n";
print "Thanks!</body></html>";
exit(0);


sub no_url {
   print "<html><head><title>ERROR: No URL</title></head>\n";
   print "<body bgcolor=#FFFFFF text=#000000>";
   print "<center><h1>No URL $new_url</h1></center>\n";
   print "You forgot to enter a url you wanted added to the  ";  
   print "link page.  Another possible problem was that your link ";
   print "was invalid.<p>\n";
   print "<form method=POST action=\"$linkscgi\">\n";
   &get_fields;
   print "<input type=submit> * <input type=reset>\n";
   print "<hr>\n";
   print "</form></body></html>\n";

   exit(0);
}

sub no_illegal_chars {
   print "<html><head><title>ERROR: No URL</title></head>\n";
   print "<body bgcolor=#FFFFFF text=#000000>";
   print "<center><h1>No Illegal Characters</h1></center>\n";
   print "Your entry contains characters that are illegal to use.";  
   print "<p>\n";
   print "<form method=POST action=\"$linkscgi\">\n";
   &get_fields;
   print "<input type=submit> * <input type=reset>\n";
   print "<hr>\n";
   print "</form></body></html>\n";

   exit(0);
}

sub no_title {
   print "<html><head><title>ERROR: No Title</title></head>\n";
   print "<body bgcolor=#FFFFFF text=#000000>";
   print "<center><h1>No Title</h1></center>\n";
   print "You forgot to enter a title you wanted added to the ";
   print " link page.  Another possible problem is that your title ";
   print "contained illegal characters.<p>\n";
   print "<form method=POST action=\"$linkscgi\">\n";
   &get_fields;
   print "<input type=submit> * <input type=reset>\n";
   print "<hr>\n";
   print "</form></body></html>\n";

   exit(0);
}


sub no_emailid {
   print "<html><head><title>ERROR: No EMail Id</title></head>\n";
   print "<body bgcolor=#FFFFFF text=#000000>";
   print "<center><h1>No E-mail ID</h1></center>\n";
   print "You forgot to enter your e-mail id. "; 
   print "Another possible problem is that your e-mail id ";
   print "contained illegal characters.<p>\n";
   print "<form method=POST action=\"$linkscgi\">\n";
   &get_fields;
   print "<input type=submit> * <input type=reset>\n";
   print "<hr>\n";
   print "</form></body></html>\n";

   exit(0);
}


sub get_fields {
   print "\nEMail: <input type=text name=\"email\" value=\"$client_ema
+il\" size=30><br>";
   print "\nTitle: <input type=text name=\"title\" value=\"$new_title\
+" size=40><br> ";
   print "\nURL: <input type=text name=\"url\" value=\"$new_url\" size
+=55><br>";
   print "<input type=hidden name=\"section\"";
   print "value=\"$where\">\n";
   
   if ($LOC ne "ALL") {
        print "<input type=hidden name=\"lnkuser\"";
           print "value=\"$LOC\">\n";
           }
   }

sub not_allowed {
    $error = $_[0];
   print "<html><head><title>ERROR: URL Entry Denied</title></head>\n"
+;
   print "<body bgcolor=#FFFFFF text=#000000>";
   print "<center><h1>URL Entry Denied</h1></center>\n";
   print "<center>Sorry, $error\n";
   print "You cannot add this URL to this page.<p>\n";
   print "</center>";
   print "</body></html>\n";

   exit(0);
}   



sub gen_code {
    my ($sec,$min,$hour,$mday,$mon,$year,$wday) = (localtime(time))[0,
+1,2,3,4,5,6];
    if ($sec<10) {$sec = "0".$sec;}
    if ($min<10) {$min = "0".$min;}
    if ($hour<10) {$hour = "0".$hour;}
    if ($mday<10) {$mday = "0".$mday;}
    my $RND = int(rand(1000));
    my $CODE = "$mday$hour$min$sec$RND";
    return $CODE;
}

sub convert_bad_chars {
    my $string = $_[0];
    $string =~ s/'/\\'/g;
    $string =~ s/"/\\"/g;
    return $string;
}

      [download]
[reply]
[d/l]
        A simple Google Search came up with this. According to this, that message appears when your headers are too large (over 8k). It also can happen when your request times out.

        And relatively unrelated to your problem: please check out HTML::Template. It'll really help you maintain all the html embedded in your code...

        [ ar0n ]

[reply]
        Well, I don't see anywhere where you are: 
        print $cgi->header();

        [download]
        or the like -- so that would be the first thing I would check out.

        To further test things I would run the code at the command line and see what is actually getting printed out. This should illuminate alot. You can run it at the command line by doing.. 

        ./foo.cgi var1=val1 var2=val2

        [download]
        where "foo.cgi" is your actual program name; "var1" etc, are each of the variables you are referencing; and "val1" etc, are values to test in those variables.

        The script should then run and you will be able to see what is trying to be sent to the browser.. you will like see something strange appear -- and that will likely be your error.

[reply]
[d/l]
[select]

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