How to resize or scale a list of images on linux

Here is a simple but powerful command when you got several images that you want to shrink:


mogrify -scale 50% *.jpg


This will reduce all the images by 50%


Or if you just want to reduce one image to 200x200 pixels for example:



convert -scale 200x200 image.jpg image_small.jpg


LPI 102 exam reference card (or cheat sheet if you like)

I recently cleared the LPIC-1 certification (LPI certification Level 1) , as an educational exercise to study for my second exam (exam 102) I created a reference card that helped me remember some commands and key concepts for the exam.

I want to share this to anyone interested in taking this exam or just anyone who wants a quick linux reference card to the objectives included in the exam.

Download

PNG version: lpi-102-reference-card-v1.png

PDF version: lpi-102-reference-card-v1.pdf

Installing Oracle OCI8 and PHP

I will describe here the steps I needed to install oracle connectivity for php. It's supposed you have php installed, in my case
I had php 5.1.6 throught RPM:

# rpm -qa | grep php
php-5.1.6-20.el5_2.1
php-adodb-4.81-1.el5.rf
php-pecl-mailparse-2.1.1-1.el5.rf
phpmyadmin-2.11.8.1-1.el5.rf
php-odbc-5.1.6-20.el5_2.1
php-pecl-fileinfo-1.0.4-1.el5.rf
php-cli-5.1.6-20.el5_2.1
php-pear-file-1.2.2-1.el5.rf
php-eaccelerator-5.1.6_0.9.5.2-4.el5.rf
php-pecl-memcache-2.1.2-1.el5.rf
php-pear-db-1.7.13-2.el5.rf
php-common-5.1.6-20.el5_2.1


Distro:

# cat /etc/redhat-release
Red Hat Enterprise Linux Server release 5 (Tikanga)

1. Download and install the Instant Client rpms from oracle which you can get here http://www.oracle.com/technology/tech/oci/instantclient/instantclient.html.

This are the two files needed in my case:

# rpm -ivh oracle-instantclient11.1-basic-11.1.0.7.0-1.x86_64.rpm

# rpm -ivh oracle-instantclient11.1-devel-11.1.0.7.0-1.x86_64.rpm


2. Compile and install the oci8 extension:

Make sure you have the proper packages to compile a script like: php-devel, gcc,etc.


# pear install pecl/oci8

I used pear install pecl/oci8 instead of pear install oci8 because for some reason the second one returns an out of memory error and ignores the memory limit variable (memory_limit = XX ) from the
php.ini file.


When asked about this:

Please provide the path to the ORACLE_HOME directory. Use 'instantclient,/path/to/instant/client/lib' if you're compiling with Oracle Instant Client : autodetect

If you have oracle installed in the same server just hit enter. If not (you just want to connect to another server) type:

instantclient and enter or the path to the oracle libraries e.g: /usr/lib/oracle/11.1/client64/lib/.


3. Finally, edit your php.ini file (/etc/php.ini) and add the extension=oci8.so in the Dynamic extensions section. Don't forget to restart apache so the changes take effect in apache.


Additional information can be found here: http://www.oracle.com/technology/pub/notes/technote_php_instant.html.

How to solve no sound in flash videos ( fedora )

After installing flash-plugin-9.0.124.0-release.i386 rpm I just got the flash plugin in my firefox but didn't get any sound. Googling about it I found a solution that worked, you need to install libflashsupport rpm, restart firefox and that's it:

just type this:

yum install libflashsupport


I guess this may work in other red hat based distros.

PHP Fatal error: Class 'DomDocument' not found in ...

After running symfony propel-build-all on a new symfony installation got this error. The solution is to install the php-xml rpm (deb).

[root@devel2 cms]# symfony propel-build-all
>> schema converting "/home/sfprojects/cm...lugin/config/schema.yml" to XML
>> schema putting /home/sfprojects/cms/pl...erated-sfGuardPlugin-schema.xml
>> file+ config/generated-sfGuardPlugin-schema.xml
>> file- /home/sfprojects/cms/plugins/sf...erated-sfGuardPlugin-schema.xml
Buildfile: /usr/share/pear/symfony/vendor/propel-generator/build.xml
[resolvepath] Resolved /home/sfprojects/cms/config to /home/sfprojects/cms/config

propel-project-builder > check-project-or-dir-set:

propel-project-builder > check-project-set:

propel-project-builder > set-project-dir:

propel-project-builder > check-buildprops-exists:

propel-project-builder > check-buildprops-for-propel-gen:

propel-project-builder > check-buildprops:

propel-project-builder > configure:
[echo] Loading project-specific props from /home/sfprojects/cms/config/propel.ini
[property] Loading /home/sfprojects/cms/config/propel.ini

propel-project-builder > om:
[phing] Calling Buildfile '/usr/share/pear/symfony/vendor/propel-generator/build-propel.xml' with target 'om'
[property] Loading /usr/share/pear/symfony/vendor/propel-generator/./default.properties

propel > check-run-only-on-schema-change:

propel > om-check:

propel > om:
[echo] +------------------------------------------+
[echo] | |
[echo] | Generating Peer-based Object Model for |
[echo] | YOUR Propel project! (NEW OM BUILDERS)! |
[echo] | |
[echo] +------------------------------------------+
[phingcall] Calling Buildfile '/usr/share/pear/symfony/vendor/propel-generator/build-propel.xml' with target 'om-template'
[property] Loading /usr/share/pear/symfony/vendor/propel-generator/./default.properties

propel > om-template:
[propel-om] Target database type: mysql
[propel-om] Target package: lib.model
[propel-om] Using template path: /usr/share/pear/symfony/vendor/propel-generator/templates
[propel-om] Output directory: /home/sfprojects/cms
[propel-om] Processing: schema.xml
PHP Fatal error: Class 'DomDocument' not found in /usr/share/pear/symfony/vendor/propel-generator/classes/propel/phing/AbstractPropelDataModelTask.php on line 406

Mplayer crashes using beryl compiz-fusion

When you start to use compiz-fusion and all the fancy desktop effects you will notice a little problem, you can't watch videos!. There's a bug that crashes mplayer, totem and all your video players. Hopefully there's a workaround for mplayer (not sure how to solve the problem with totem).

1. Open mplayer.
2. Right click over the window.
3. Click on preferences.
4. Click on the Video tab .
5. Change the video driver from Xv to X11 and click Ok.

You may have to restart mplayer to see the changes.

Vista Blue Screen of Death: STOP: 0x0000008E

The famous blue screen of death attacked me again (previous bsod), this time on Vista, on my Dell inspiron 1520. It's very annoying that you have to deal with this kind of errors on a laptop recently bought. This error started to display a few seconds after logging in to the user account and with no clear reason of what could be the trigger of the error.

The solution this time actually had nothing to do (directly) with Windows Vista but with the laptop BIOS, and the solution came from the dell support site support.dell.com, the error itself suggested to update the BIOS , but I don't pay too much attention to this general error messages. If you're having this same problem you could go and follow this check list from dell, the BIOS upgrade was the second suggestion for a BSOF error and this was the one that worked for me, the file to do this is in the "Drivers and Downloads" section and you can select between all the different models.

Subversion: MKCOL of '...' 405 Method Not Allowed

I was messing with the .svn/entries file in one of my local working copy folders, also I rm -rf a folder and regenerated again (I'm using symfony admin generator) , long story, but the fact is that I think I screwed up something and started to get this error when trying to commit:

# svn commit -m "backend modifications"
Adding apps/backend/modules/comment
svn: Commit failed (details follow):
svn: MKCOL of '/projects/cms/!svn/wrk/5ca09002-f34f-0410-890e-9511925f86a5/trunk/apps/backend/modules/comment': 405 Method Not Allowed (http://svn.calipso.com.co)

After some googling, I found it could be some proxy problem, but I wasn't using a proxy. Later I found that this error could mean that
the directory already existed in the repository and couldn't be recreated again, so my next step was to delete the folder from the repository (svn del ...) and try to do a fresh commit after recreating the folder and files included in it, and this worked ;).

I hope this helps some lost soul out there.