Keynote like multi-screen output in linux

I normally create my presentations using the beamer package in Latex compiling them into pdf, can't really imagine why would anyone use anything else. I use evince to display the pdf on a projector, but found it to be relatively basic.

I was looking for an application to display some meta-information like the remaining time and the preview of the next slide on my laptop while displaying the current slide on the projector, the way Keynote does it. I found the pdf_presenter_console application, it is fairly minimalistic but seems to do the trick for me.

PHP Fatal error: Class 'PDO' not found

When using SQLite with Php for the first time, you might get this error under /var/log/httpd/error_log (I was using a Fedora 13 machine). The trick is to install a package called "php-pdo" and then use the function.

su

yum install php-pdo

Hopefully it will save someone some heartache :)

StrongSwan: we have no ipsecN interface for either end of this connection

I installed a new NIC card on one of my PCs where IPSec was already set up through StrongSwan and configured NAT-ing through iptables. Afterward, when I tried to do "ipsec up myconnection" I got this error:

we have no ipsecN interface for either end of this connection

The reason, it turns out, is that if the ipsec services were started before all the network interfaces came up, it is confused about which egress route to take. As I found on the Layer9 blog (and translated from German to English via Babelfish), it turns out you need to make sure that ipsec starts after the network has come up. The quick fix was just an IPSec restart:

sudo /etc/init.d/ipsec restart

And the long-term fix was definitely to just delay the ipsec a little. Add this to your /etc/rc.local file:

/etc/init.d/ipsec stopsleep 5/etc/init.d/ipsec start

Strongswan: ike alg: unable to locate my private key

If you are using StrongSwan to establish an IPSec connection and you encounter this error:

root@crackjack:~# ipsec up conn-to-td
002 "conn-to-td" #2: initiating Main Mode
002 "conn-to-td" #2: ike alg: unable to locate my private key
002 "conn-to-td" #2: ike alg: unable to locate my private key
003 "conn-to-td" #2: empty ISAKMP SA proposal to send (no algorithms for ike selection?)

Then I have found the way to solve the first part of your problem - the private key part. Basically, after FreeSwan became OpenSwan and then finally StrongSwan, they created a directory for each individual part under /etc/ipsec.d. So for example the CA certs are stored in the folder /etc/ipsec.d/cacerts, or the certs you got are stored in /etc/ipsec.d/certs. Similarly, you are supposed to store your private key at /etc/ipsec.d/private. What you have probably done is that in /etc/ipsec.conf you wrote down

leftcert=/etc/ipsec.d/private/my_private_key.pem

When in fact you should have your /etc/ipsec.conf as the following:

# ipsec.conf - strongSwan IPsec configuration file

# basic configuration

config setup
    plutodebug=all
    plutostderrlog=/var/log/pluto.log
    charonstart=yes
    plutostart=yes


conn host-to-host
      left=
      leftcert=my_cert.pem
      leftid=my_private_key.pem
      right=
      rightid=
      auto=start
      pfs=no
      rekey=no
      keyingtries=3

After this, you can do the faithful /etc/init.d/ipsec restart and the private key problem will disappear

Ubuntu/ALSA controlling volume from the command line

If you are using ALSA as your audio framework, if you are using a common distribution like Ubuntu you probably are, there is a command line program called alsamixer which provides an elaborate set of options to control your sound settings.

The sound setting I most often tinker with is, of course, raising and lowering the volume. A simple way to do that on the command line is "amixer -c 0 sset Master,0 %", for e.g. amixer -c 0 sset Master,0 60%.

mediawiki blank page after install

If you have freshly installed MediaWiki and are getting a blank page after installing, here is what you are probably doing wrong: the LocalSettings.php needs to have read permissions by everyone as well.

(I am assuming a standard install here)
So if you go to /var/lib/mediawiki/LocalSettings.php it should actually be a softlink to /etc/mediawiki/LocalSettings.php. Try this command:

sudo chmod 755 /etc/mediawiki/LocalSettings.php

And then restart apache (just to make sure):

sudo /etc/init.d/apache restart

That should be it. Now your http://localhost/mediawiki should be visible :)

VMWare tries network boot although you've specified an ISO file in the device settings

It just happened to me, and I found the solution thanks to my teammate. You have to click on the check-box under CDRom that says "Connect at power on". By default, when you add a new CDRom to the machine, this box is not checked. So, there goes...