Update Oracle for Hostname Change:

Edit both the listener.ora and tnsnames.ora files at $ORACLE_HOME/network/admin/listener.ora and $ORACLE_HOME/network/admin/tnsnames.ora. In the files, replace instances of the old hostname with the new hostname. Finally, log into root and force a reload.

> su -
> /etc/init.d/oracle-xe force-reload

Cascading Style Sheet Definition:

<style type="text/css">
   table.apexir_WORKSHEET_DATA td {
      white-space:nowrap;
   }
</style>

Go to the Region Definition of the interactive report. In the Header and Footer section, place the above Cascading Style Sheet (CSS) definition in the Region Header.

First, Install PPTPD:

> rpm -Uhv http://poptop.sourceforge.net/yum/stable/fc16/pptp-release-current.noarch.rpm
> yum install pptpd

As root, add the Poptop stable repository for Fedora Linux 16 and install the pptpd package. For CentOS 5, substitute fc16 with rhel5.

Configure PPTPD:

> vi /etc/pptpd.conf

localip 111.111.111.111
remoteip 10.10.1.2-254

> cat /etc/resolv.conf

nameserver 222.222.222.222
nameserver 333.333.333.333

> vi /etc/ppp/options.pptpd

ms-dns 222.222.222.222
ms-dns 333.333.333.333

refuse-mschap
require-mschap-v2
require-mppe-128
require-mppe

First, edit the /etc/pptpd.conf file. localip is the server’s IP address (or the address that the remote clients will connect to). List the server’s IP address with the ifconfig command. remoteip is the range of internal IP addresses that the PPTP VPN server will assign to the remote clients as they connect to the VPN.

Next list the contents of the /etc/resolv.conf file to discover the DNS addresses that the server is using. Then edit the /etc/ppp/options.pptpd file and change the ms-dns entries to match those DNS addresses. Or use the OpenDNS addresses 208.67.220.220 and 208.67.222.222. Before closing the file, also edit the authentication protocols as listed above.

Configure Clients:

> vi /etc/ppp/chap-secrets

mnguyen pptpd password1 *
snguyen pptpd password2 *

Add the username, server, password, and allowable IP addresses for each client. This example uses a wildcard to allow both clients to connect to the PPTP VPN server from any IP address.

Enable Packet forwarding:

> vi /etc/sysctl.conf

net.ipv4.ip_forward = 1

> sysctl -p

Edit the /etc/sysctl.conf file to allow packet forwarding and enable it immediately with the sysctl -p command.

Modify Default MTU:

> vi /etc/ppp/ip-up

ifconfig $1 mtu 1400

Modify the default MTU to enable live chat and other services to run via the PPTP VPN server. Add the ifconfig $1 mtu 1400 line before the exit 0 line in the file.

Configure iptables:

> iptables -A INPUT -i p3p1 -p tcp --dport 1723 -j ACCEPT
> iptables -A INPUT -i p3p1 -p gre -j ACCEPT
> iptables -A FORWARD -i ppp+ -o p3p1 -j ACCEPT
> iptables -A FORWARD -i p3p1 -o ppp+ -j ACCEPT
> iptables -A OUTPUT -p tcp --dport 1723 -j ACCEPT
> iptables -A OUTPUT -p gre -j ACCEPT
> iptables -t nat -A POSTROUTING -o p3p1 -j MASQUERADE

Add the above rules to allow connections to the PPTP VPN server through the firewall. p3p1 is the interface and may be eth0, eth1, venet0, etc.

For a BuyVM OpenVZ virtual private server (VPS) running CentOS 5, substitute the iptables -t nat -A POSTROUTING -o p3p1 -j MASQUERADE line with iptables -t nat -A POSTROUTING -s 10.0.0.0/8 -j SNAT --to-source 999.999.999.999 instead (where 999.999.999.999 is the internal IP address provisioned for the VPS).

Finally, Start PPTPD:

> service pptpd start
> chkconfig --level 2345 pptpd on

]]> http://minhtech.com/linux/fedora-linux-16-install-pptp-vpn-server-pptpd/feed/ 7 http://minhtech.com/miscellaneous/google-chrome-pin-web-sites-on-new-tab-page/ http://minhtech.com/miscellaneous/google-chrome-pin-web-sites-on-new-tab-page/#comments Fri, 16 Dec 2011 13:38:35 +0000 Minh http://minhtech.com/?p=1114 Here is how to pin Web sites on the “New Tab Page” of Google Chrome 15 or 16. For some reason, the pin button has been removed from the recent releases but the functionality still exists. This section of the New Tab Page used to be titled “Most visited.”

First, Open the Preferences file:

Windows 7: \Users\Username\AppData\Local\Google\Chrome\User Data\Default\Preferences
MAC OS X: /Users/Username/Library/Application Support/Google/Chrome/Default/Preferences

Completely exit Google Chrome and make sure all windows are closed. Open the Preferences file in your favorite text editor.

Edit the Preferences file:

"pinned_urls": {
   "http://www.domain1.com/": 1,
   "http://www.domain2.net/": 2,
   "http://www.domain3.org/": 0
},

Look for the section listed above and edit it. You may have up to 8 pinned Web sites numbered 0 to 7 in the Preferences file. The number indicates the order of the pinned sites.

First, Download and Unarchive the Source:

Version 0.79 can be downloaded from Eric Smith’s site at http://nonpareil.brouhaha.com/download/. I will be installing version 0.78 which has the Voyager series models that include my beloved HP 15c.

> gzip -d nonpareil-0.78.tar.gz
> tar -xvf nonpareil-0.78.tar
> cd nonpareil-0.78

Install Build Dependencies:

> yum install gcc flex bison scons python netpbm netpbm-progs

We install all the build dependencies listed in the source’s INSTALL file. We also install the netpbm-progs package for the pngtopnm command. Otherwise we will later receive a sh: pngtopnm: command not found error message.

Install Runtime Dependencies:

> yum install gtk2 gtk2-devel gdk-pixbuf2 gdk-pixbuf2-devel glib2 glib2-devel libxml2 libxml2-devel SDL SDL-devel SDL_mixer SDL_mixer-devel

Next we install the runtime dependencies listed in the README file. Note that the corresponding header files must also be installed as stated in the source’s INSTALL file.

Install Nonpareil:

> scons install

<command-line>:0:1: error: macro names must be identifiers
scons: *** [build/posix/csim.o] Error 1
scons: building terminated because of errors.

Oops, it looks like a source file needs to be modified. Search for the line csim_env.Append (CPPDEFINES = {'DEFAULT_PATH': build_env ['libdir']}) and edit it as listed below.

> vi src/SConscript

csim_env.Append (CPPDEFINES = [('DEFAULT_PATH', build_env ['libdir'])])

> scons install

scons: done building targets.

That’s it. The nonpareil command can be found at the path /usr/local/bin/. Enjoy!

Analyze EBCDIC File:

Suppose we have a file in EBCDIC format with the following field name, offset, size, and data type elements:

field_01 0 7 packed decimal(14)
field_02 7 4 integer(4)
field_03 11 4 ebcdic string(4)

Note the numeric field length. Each byte of a packed decimal contains two digits. So “field1″ is 7 * 2 = 14 = 13 digits plus the symbol.

Create the Perl Script:

> vi ebcdic2ascii.pl

#!/usr/bin/perl -w

use strict;
use Convert::EBCDIC;

sub convert2ascii_decimal {
   my ($number) = unpack('H*', $_[0]);
   my ($sign) = chop $number;
   my ($scale) = $_[1];

   if ($scale > 0) {
      $number = (substr $number, 0, -$scale) . '.' . (substr $number, -$scale);
   }

   if ($sign eq 'd') {
      $number = -$number;
   }

   return $number;
}

sub convert2ascii_integer {
   my ($integer) = @_;

   return unpack('i', $integer);
}

sub convert2ascii_string {
   my ($string) = @_;

   return Convert::EBCDIC::ebcdic2ascii($string);
}

sub filewrite {
   my ($file, $string) = @_;

   open FH, '>>', $file or die $!;
   select FH;
   print "$string\n";
   select STDOUT;
   close FH or die $!;
}

sub recordparse {
   my ($record) = @_;
   my $string;

   $string = undefined2defined(convert2ascii_decimal((substr $record, 0, 7), 2));
   $string = $string . chr(9) . undefined2defined(convert2ascii_integer((substr $record, 7, 4)));
   $string = $string . chr(9) . undefined2defined(convert2ascii_string((substr $record, 11, 4)));

   return $string;
}

sub undefined2defined {
   my ($string) = @_;

   if (defined $string) {
      return $string;
   }
   else {
      return '';
   }
}

my $string;

open (FILE, $ARGV[0]) or die $!;

while ((read FILE, $string, 14) != 0) {
   filewrite ($ARGV[1], recordparse($string));
}

close(FILE) or die $!;

exit;

In this example, the main procedure is reading in 14 characters at a time from the file, which is the record length. The function recordparse parses each record by calling convert2ascii_decimal, convert2ascii_integer, and convert2ascii_string; these functions unpack packed decimals, unpack integers, and convert EBCDIC strings to ASCII respectively.

Note that the code using convert2ascii_decimal has a third highlighted parameter, field scale, in addition to field offset and field length. In this example, “field1″ has a field offset of 0, a field length of 7, and a field scale of 2 (or 2 decimal places).

Finally, Run the Script:

> perl ebcdic2ascii.pl ebcdic.ods ascii.txt

First, Check iptables:

> su -
> head -20 /etc/ssh/sshd_config

# $OpenBSD: sshd_config,v 1.81 2009/10/08 14:03:41 markus Exp $

# This is the sshd server system-wide configuration file. See
# sshd_config(5) for more information.

# This sshd was compiled with PATH=/usr/local/bin:/bin:/usr/bin

# The strategy used for options in the default sshd_config shipped with
# OpenSSH is to specify options with their default value where
# possible, but leave them commented. Uncommented options change a
# default value.

Port 9090
#AddressFamily any
#ListenAddress 0.0.0.0
#ListenAddress ::

# The default requires explicit activation of protocol 1
Protocol 2

> /etc/init.d/sshd status

openssh-daemon (pid 1309) is running…

> /etc/init.d/iptables status

Table: filter
Chain INPUT (policy DROP)
num target prot opt source destination
1 ACCEPT tcp — 0.0.0.0/0 0.0.0.0/0 tcp dpt:80
2 ACCEPT all — 0.0.0.0/0 0.0.0.0/0 state RELATED,ESTABLISHED
3 ACCEPT all — 0.0.0.0/0 0.0.0.0/0

Chain FORWARD (policy DROP)
num target prot opt source destination

Chain OUTPUT (policy ACCEPT)
num target prot opt source destination

Log into root and check the port binding. In this example, we are binding sshd to port 9090 and confirm that sshd is running. Then we check iptables and notice there is no explicit rule to allow access to port 9090.

> iptables -A INPUT -i eth0 -p tcp --dport 9090 -j ACCEPT

So we create a firewall rule to allow access to port 9090 via interface eth0. Omitting the interface parameter would allow access to port 9090 via all network interfaces.

Next, check SELinux:

> /etc/init.d/sshd start
> /etc/init.d/sshd status

openssh-daemon is stopped

> cat /etc/selinux/config

# This file controls the state of SELinux on the system.
# SELINUX= can take one of these three values:
# enforcing – SELinux security policy is enforced.
# permissive – SELinux prints warnings instead of enforcing.
# disabled – No SELinux policy is loaded.
SELINUX=enforcing
# SELINUXTYPE= can take one of these two values:
# targeted – Targeted processes are protected,
# mls – Multi Level Security protection.
SELINUXTYPE=targeted

In this case, we attempt to start sshd but it is not running, and then check the SELinux configuration. SELinux policy is enforcing. You could edit the config file and make SELinux policy permissive or disabled but that is not recommended. Instead, you should configure SELinux to allow sshd to bind to port 9090.

> semanage port -a -t ssh_port_t -p tcp 9090

This is especially useful if you lack Windows administrator privileges, such as on an employer-maintained workstation, and cannot install a PDF application or printer driver. If you have Microsoft Office installed, you can “print” into a XPS document with the Microsoft XPS Document Writer printer driver, and then convert it into PDF for easy distribution.

First, Download GhostPDL:

Go to Ghostscript’s Google Project Home and download the already compiled GhostPDL Windows binaries here. No compiling or installation is required. Simply uncompress the ZIP archive and you are ready to go.

Convert XPS to PDF via Command Line

Open a command prompt by going to Start > Programs > Accessories > Command Prompt, and then use the following syntax. You may also use the run prompt via Start > Run.

C:\gxps-871.exe -sDEVICE=pdfwrite -sOutputFile=myfile.pdf -dNOPAUSE myfile.xps

You may need to use absolute paths. Here I am using the gxps binary installed in the My Documents directory to convert a file on the Desktop.

C:\"C:\Documents and Settings\Minh Nguyen\My Documents\ghostpdl-8.71-win32\gxps-871.exe" -sDEVICE=pdfwrite -sOutputFile="C:\Documents and Settings\Minh Nguyen\Desktop\file.pdf" -dNOPAUSE "C:\Documents and Settings\Minh Nguyen\Desktop\file.xps"

ManualUpdate and AutoSort Workaround:

Dim mySheet As Worksheet
Dim myTable As PivotTable, myField As PivotField, myItem As PivotItem

Set mySheet = Sheets(1)
Set myTable = mySheet.PivotTables(1)
Set myField = myTable.PivotFields(1)

For Each myItem In myField.PivotItems
    myField.AutoSort xlManual, myField.SourceName
    myTable.ManualUpdate = True

    myItem.Visible = True

    myTable.ManualUpdate = False
    myField.AutoSort xlAscending, myField.SourceName
Next myItem

The workaround is to temporarily enable ManualUpdate in the PivotTable and disable AutoSort in the PivotField. Download pivot.xls for a sample of the error and the workaround.

First, Install Packages:

> su -
> yum install perl mplayer ffmpeg ImageMagick
> exit

Log into root and install the necessary packages. The RPM Fusion repository needs to be configured for mplayer, ffmpeg, and ImageMagick.

Copy Perl Script:

> vi thumbs.pl

#!/usr/bin/perl -w

use strict;
use POSIX;

my $dir = getcwd();
my ($width, $height, $length);

opendir(DIR, $dir) or die $!;

while (my $file = readdir(DIR)) {
   next unless ($file =~ m/\.mp4$/);

   my @info = `mplayer -benchmark -nosound -quiet -vo null -frames 1 -identify $file`;

   foreach (@info) {
      if (substr($_, 0, 15) eq "ID_VIDEO_WIDTH=") {
         $width = substr($_, 15);
      }
      elsif (substr($_, 0, 16) eq "ID_VIDEO_HEIGHT=") {
         $height = substr($_, 16);
      }
   elsif (substr($_, 0, 10) eq "ID_LENGTH=") {
         $length = substr($_, 10);
      }
   }

   $width = floor($width / 3);
   $height = floor($height / 3);
   my ($tile_x, $tile_y, $frame) = (6, 4, 1);
   my ($position, $files);

   while ($frame < ($tile_x * $tile_y + 1)) {
      $position = $frame * floor($length / ($tile_x * $tile_y));

      system("ffmpeg -ss $position -i $file -vcodec mjpeg -vframes 1 -s $width"."x"."$height -an -f rawvideo -y __$frame.jpg 2> /dev/null");

      $files = $files . " __$frame.jpg";

      $frame += 1;
   }

   system("montage -title \"$file\" -geometry $width"."x"."$height"."+"."1"."+"."1 -tile $tile_x"."x"."$tile_y$files $file.jpg");

   system("rm __*.jpg");
}

closedir(DIR);

You can also download the thumbs.pl file.

There are a few things you may wish to configure. First is the script only creates montages for mp4 files. Change the regular expression for your needs. Second is the scale of each thumbnail relative to the resolution of the video. I have selected one-third of the original size. Third is the tile layout. I have selected 6 horizontal by 4 vertical tiles. If you are editing the script, note that the -ss option must be before the -i option or else ffmpeg will crawl while creating thumbnails.

Why both mplayer and ffmpeg? mplayer has the ability to do montages but I usually have issues with the -sstep option, and framestep is way too slow. You can certainly pull video data with ffmpeg -i but mplayer -identify is much easier to parse and I was lazy. Sorry.

Run the Perl Script:

> perl thumbs.pl

Place the script into a directory and execute it. You can run it in the background with nohup perl thumbs.pl & instead. The script will find every mp4 file in its directory and make a sequential video thumbnail montage for it.

Update February 14, 2011:

mplayer: could not connect to socket
mplayer: No such file or directory
Failed to open LIRC support. You will not be able to use your remote control.

> vi ~/.mplayer/config

nolirc=yes

Linux Infrared Remote Control (LIRC) support in mplayer is compiled by default in Fedora Linux. If you do not have a remote or if you wish to disable support, edit the mplayer config file in your home directory to add the nolirc option.