I have an issues on Web application programming with Firebird.
I'm using mod_perl and Apache::DBI with Firebird.
And also using CGI::Session for session handling.
CGI::Session uses an already connected $dbh with Firebird.
AutoCommit is ON.
Every(multiple) sql execution is wrapped by eval {} statement.
for example,
$dbh = DBI->connect("dbi:Firebird:db=$DBSERVER:/home/cdbs/xxnet.fdb;
ib_charset=UTF8;ib_dialect=3",$DBUSER,$DBPASS,{
AutoCommit=>1,
LongReadLen=>8192,
RaiseError=>1
});
eval { $dbh->begin_work()
my $sql = "SELECT * FROM SAMPLETABLE"
my $st = $dbh->prepare($sql);
$st->execute();
while (my $R = $st->fetchrow_hashref()) {
...
}
$st->finish();
}; warn $# if $#;
if ($#) {
$dbh->rollback();
}else{
$dbh->commit();
}
When an exception was raised in eval section, execute warn statement and try to rollback transaction.
Error messages are logged in error_log,after that, $dbh is going to get stuck -- CGI::Session returns no data.
I thought 'warn' statement includes 'rollback', so I tried to comment out $dbh->rollback() statement. It looks good.
Other ways, I use 'warn' to log debug message -- like print STDERR $#.
httpd is going to get stuck like as above.
With Oracle(DBD::Oracle), I didn't see these situation.
Please tell me which part is BAD for using transaction with firebird ?
warn ? DBD::Firebird ?
Thanks.
Yasuto,
Related
I try to download huge file which takes a lot of time downloading from ftp link using perl.
I got:
Timeout at C:/Strawberry/perl/lib/Net/FTP.pm
what does this means and how to solve it?
Thanks
Solution:
Thanks #Chris Doyle
I change the timeout value in my perl file "not ftp.pm file"
Thanks
You can increase the timeout, but it is important that if the timeout is reached again and your server/client are out of sync, it might throw the same error you got the first time, again.
It seems that the issue is due a lack of error handling in your Perl Script instead.
Surely you have something like this at your perl script:
my $ftp = Net::FTP->new( $myhost, Timeout => 10, Debug => 1 );
...
$ftp->get($myfile) or print "Got an error";
$ftp->quit();
Please notice this is out of .../perl/lib/Net/FTP.pm, since the
FTP.pm is the third party module (Kind of library) you are using to
reach the ftp, I suggest you to not touch it to avoid portability
issues later on.
Normally the timeout is reached inside the FTP.pm and it goes to the or print "Got an error" condition, but there are some cases, that the Server/Client just get out of sync and the FTP.pm just throws an unhandled exception.
This exception will NOT go to the or print "Got an error" condition, therefore you need to catch it and handle it as any other languages.
Here you can use eval to wrap it up the code, catch the exception and handle it as you need.
For example:
my $ftp = Net::FTP->new( $myhost, Timeout => 10, Debug => 1 );
...
eval {$ftp->get($myfile) or print("Can't get file $myfile") };
if ($# =~ /Timeout/) {
print "Got a timeout Issue: $#";
}
$ftp->quit();
I'm writing a small script to monitor if certain ports are attempted to be accessed on my Linux box (Centos 6) using Perl 5.10.1. I'm getting back blank entries for my peerhost request. I'm not sure why. It sounds like it may be a failure in the IO socket module (http://snowhare.com/utilities/perldoc2tree/example/IO/Socket.html) but I'm not really sure. Any insight would be much appreciated.
EDIT:
Since I enabled the strict and warnings I'm getting an 'uninitialized value $display' in the cases where I thought it was blank.
#! /usr/bin/perl
use strict;
use warnings;
use IO::Socket;
use Sys::Syslog qw( :DEFAULT setlogsock);
use threads;
my #threads=();
my #ports=(88,110,389);
main(\#ports);
sub main
{
my $ports=shift;
setlogsock('unix');
openlog($0,'','user');
for my $port (#{$ports} ) {
push #threads, threads->create(\&create_monitor, $port );
}
$_->join foreach #threads;
closelog;
# wait for all threads to finish
}
sub create_monitor{
my $LocalPort=shift;
my $sock = new IO::Socket::INET (
LocalPort => $LocalPort,
Proto => 'tcp',
Listen => 1,
Reuse => 1,
) or die "Could not create socket: $!\n";
while(1)
{
my $peer_connection= $sock->accept;
my $display = $peer_connection->peerhost();
my $message="Connection attempt on port $LocalPort from $display";
#syslog('info', $message);
print $message."\n";
}
}
NOTE - it is intentional that this script never finish. I'll eventually wrap this with an init script and have it run as a service.
Perl accept() has an error code like most other functions. For accept() it is a false return, see also here.
So when you get undefined as result there is an error in accept() call. The error of accept is saved in the errno variable ($!).
Same is true for peerhost() (see here). It also can fail and return an error code.
If you only use the above code without anything else, then probably you reach connection limit of your system (you should close the connections) when accept() fails. See rlimit() to find out how that number can be increased.
One case where peerhost() fails may be that remote connection was closed already.
I have a perl script which connects to a Sybase db server (alias for server - MYDATABASESERVER). My code is:
exec perl -w -x
#!perl
use Sybase::DBlib;
use Mail::Sendmail;
use Env qw(DSQUERY DBNAME DBUSER DBPASSWD);
$dbh = &execRemoteSQL($sql_text);
sub execRemoteSQL
{
my ($sqlText) = #_;
my ( $ret, $retS );
local ($dbh) = undef;
$dbh = new Sybase::DBlib $DBUSER, $DBPASSWD, $DSQUERY;
if ( !(defined $dbh) )
{
print STDERR "execRemoteSQL(): Failed To Create DB Handle for :\n";
print STDERR " SERVER = $DSQUERY\n";
print STDERR " DATABSE = $DBNAME\n";
exit(-1);
}
.
.
.
When i provide the server name as MYDATABASESERVER (value of DSQUERY), I get the error in the If statement, but it connects properly to the server with name as MYDB.
Wanted to know if there is any constraint on the server name length or is it due to something else.
Here is the error messsage i am getting:
DB-Library error:
Unknown host machine name.
execRemoteSQL(): Failed To Create DB Handle for :
SERVER = MYDATABASESERVER
DATABSE = my_db
The server alias is defined properly because i am able to connect to the db using isql.
I don't think the length of the server name is too long here.
What is your exact error message?
Maybe the MYDATABASESERVER server-alias name is not defined properly in the Sybase-specific "interfaces" config file. It resides in dir $SYBASE/$SYBASE_OCS. What does it say about MYDATABASESERVER (should be 2 lines)?
In any case:
Don't use DBLib, it is really old and deprecated. I think the maintainer of the Sybperl/DBLib and DBD::Sybase modules, only still supports the Sybase::DBLib code to make life easier for client programmers who have to deal with old programs, and to keep legacy applications compatible with new releases of Sybase ASE.
You should use DBI and DBD::Sybase instead. 99% of all perl/sybase code on the internet uses DBI.
Can you try the following syntax instead? :
$dbh = Sybase::DBlib->new( $DBUSER, $DBPASSWD, $DSQUERY );
When I try to run my Perl CGI program, the returned web page tells me:
Software error: For help, please send mail to the webmaster (root#localhost), giving this error message and the time and date of the error.
Here is my code in one of the file:
#!/usr/bin/perl
use lib "/home/ecoopr/ecoopr.com/CPAN";
use CGI;
use CGI::FormBuilder;
use CGI::Session;
use CGI::Carp (fatalsToBrowser);
use CGI::Session;
use HTML::Template;
use MIME::Base64 ();
use strict;
require "./db_lib.pl";
require "./config.pl";
my $query = CGI->new;
my $url = $query->url();
my $hostname = $query->url(-base => 1);
my $login_url = $hostname . '/login.pl';
my $redir_url = $login_url . '?d=' . $url;
my $domain_name = get_domain_name();
my $helpful_msg = $query->param('m');
my $new_trusted_user_fname = $query->param('u');
my $action = $query->param('a');
$new_trusted_user_fname = MIME::Base64::decode($new_trusted_user_fname);
####### Colin: Added July 12, 2009 #######
my $view = $query->param('view');
my $offset = $query->param('offset');
####### Colin: Added July , 2009 #######
#print $session->header;
#print $new_trusted_user;
my $helpful_msg_txt = qq[];
my $helpful_msg_div = qq[];
if ($helpful_msg)
The "please send mail to the webmaster" message you see is a generic message that the web server gives you when anything goes wrong and nothing handles it. It's not at all interesting in terms of solving the actual problem. Check the error log to find possible relevant error output from your program.
And, go through my How do I troubleshoot my Perl CGI script? advice on finding the problem.
My guess is that you have a syntax error with that dangling if(). What you have posted isn't a valid Perl program.
Good luck,
is that something related to suexec module
Improper configuration of suExec can cause permission errors
The suEXEC feature provides Apache users the ability to run CGI and SSI programs under user IDs different from the user ID of the calling web server. Normally, when a CGI or SSI program executes, it runs as the same user who is running the web server.
apache recommends that you not consider using suEXEC.
http://httpd.apache.org/docs/2.2/suexec.html
From the StackOverflow page: How to trap program crashes with HTTP error code 500
I see that your include: use CGI::Carp (fatalsToBrowser);
... stifles the HTTP 500 error. Simply removing this will allow the programs to crash "properly".
I'm attempting to use an existing CAS server to authenticate login for a Perl CGI web script and am using the AuthCAS Perl module (v 1.3.1). I can connect to the CAS server to get the service ticket but when I try to connect to validate the ticket my script returns with the following error from the IO::Socket::SSL module:
500 Can't connect to [CAS Server]:443 (Bad hostname '[CAS Server]')
([CAS Server] substituted for real server name)
Symptoms/Tests:
If I type the generated URL for the authentication into the web browser's location bar it returns just fine with the expected XML snippet. So it is not a bad host name.
If I generate a script without using the AuthCAS module but using the IO::Socket::SSL module directly to query the CAS server for validation on the generated service ticket the Perl script will run fine from the command line but not in the browser.
If I add the AuthCAS module into the script in item 2, the script no longer works on the command line and still doesn't work in the browser.
Here is the bare-bones script that produces the error:
#!/usr/bin/perl
use strict;
use warnings;
use CGI;
use AuthCAS;
use CGI::Carp qw( fatalsToBrowser );
my $id = $ENV{QUERY_STRING};
my $q = new CGI;
my $target = "http://localhost/cgi-bin/testCAS.cgi";
my $cas = new AuthCAS(casUrl => 'https://cas_server/cas');
if ($id eq ""){
my $login_url = $cas->getServerLoginURL($target);
printf "Location: $login_url\n\n";
exit 0;
} else {
print $q->header();
print "CAS TEST<br>\n";
## When coming back from the CAS server a ticket is provided in the QUERY_STRING
print "QUERY_STRING = " . $id . "</br>\n";
## $ST should contain the received Service Ticket
my $ST = $q->param('ticket');
my $user = $cas->validateST($target, $ST); #### This is what fails
printf "Error: %s\n", &AuthCAS::get_errors() unless (defined $user);
}
Any ideas on where the conflict might be?
The error is coming from the line directly above the snippet Cebjyre quoted namely
$ssl_socket = new IO::Socket::SSL(%ssl_options);
namely the socket creation. All of the input parameters are correct. I had edited the module to put in debug statements and print out all the parameters just before that call and they are all fine. Looks like I'm going to have to dive deeper into the IO::Socket::SSL module.
As usually happens when I post questions like this, I found the problem. It turns out the Crypt::SSLeay module was not installed or at least not up to date. Of course the error messages didn't give me any clues. Updating it and all the problems go away and things are working fine now.
Well, from the module source it looks like that IO::Socket error is coming from get_https2
[...]
unless ($ssl_socket) {
$errors = sprintf "error %s unable to connect https://%s:%s/\n",&IO::Socket::SSL::errstr,$host,$port;
return undef;
}
[...]
which is called by callCAS, which is called by validateST.
One option is to temporarily edit the module file to put some debug statements in if you can, but if I had to guess, I'd say the casUrl you are supplying isn't matching up to the _parse_url regex properly - maybe you have three slashes after the https?