I've noticed in /var/log/apache2/error.log on one of the Debian servers I manage a lot of warnings and errors produced by tidy – HTML syntax checker and reformatter program.
There were actually quite plenty frequently appearing messages in the the log like:
...
To learn more about HTML Tidy see http://tidy.sourceforge.net
Please fill bug reports and queries using the "tracker" on the Tidy web site.
Additionally, questions can be sent to html-tidy@w3.org
HTML and CSS specifications are available from http://www.w3.org/
Lobby your company to join W3C, see http://www.w3.org/Consortium
line 1 column 1 - Warning: missing <!DOCTYPE> declaration
line 1 column 1 - Warning: plain text isn't allowed in <head> elements
line 1 column 1 - Info: <head> previously mentioned
line 1 column 1 - Warning: inserting implicit <body>
line 1 column 1 - Warning: inserting missing 'title' element
Info: Document content looks like HTML 3.2
4 warnings, 0 errors were found!
...
I did a quick investigation on where from this messages are logged in error.log, and discovered few .php scripts in one of the websites containing the tidy string. I used Linux find + grep cmds find in all php files the "tidy "string, like so:
As you see the PHP programmers who wrote this website, made a bigtidy mess. Instead of using php5's tidy module, they hard coded tidy external command to be invoked via php's exec(); external tidy command invocation. This is extremely bad practice, since it spawns the command via a pseudo limited apache shell. I've notified about the issue, but I don't know when, the external tidy calls will be rewritten.
Until the external tidy invocations are rewritten to use the php tidy module, I decided to at least remove the tidy warnings and errors output.
To remove the warning and error messages I've changed:
exec('/usr/bin/tidy --show-warnings no --show-errors no -q -e -ashtml -utf8 '.$tmp_name,$rett);
The extra switches meaning is like so:
q – instructs tidy to produce quiet output -e – show only errors and warnings –show warnings no && –show errors no, completely disable warnings and error output
Onwards tidy no longer logs junk messages in error.log Not logging all this useless warnings and errors has positive effect on overall server performance especially, when the scripts, running /usr/bin/tidy are called as frequently as 1000 times per sec. or more
A friend of mine has Fujitsu Siemens Amilo laptop and is full time using his computer with Slackware Linux.
He is quite happy with Slackware Linux 13.37 on the laptop, but unfortunately sometimes his screen brightness lowers. One example when the screen gets darkened is when he switch the computer on without being plugged in the electricity grid. This lowered brightness makes the screen un-user friendly and is quite tiring for the eye …
By default the laptop has the usual function keys and in theory pressing Function (fn) + F8 / F7 – should increase / decrease the brightness with no problems, however on Slackware Linux (and probably on other Linuxes too?), the function keys are not properly recognized and not responding whilst pressed. I used to have brigtness issues on my Lenovo notebook too and remember how irritating this was. After a bit of recalling memories on how I solved this brightness issues I remembered the screen brigthness on Linux is tunable through /proc virtual (memory) filesystem.
I took a quick look in /proc and found few files called brightness:
/proc/acpi/video/GFX0/DD01/brightness
/proc/acpi/video/GFX0/DD02/brightness
/proc/acpi/video/GFX0/DD03/brightness
/proc/acpi/video/GFX0/DD04/brightness
/proc/acpi/video/GFX0/DD05/brightness
cat-ting /proc/acpi/video/GFX0/DD01/brightness, /proc/acpi/video/GFX0/DD03/brightness, /proc/acpi/video/GFX0/DD04/brightness all shows not supported and therefore, they cannot be used to modify brightness:
bash-4.1# for i in $(/proc/acpi/video/GFX0/DD0{1,3,4,5}/brightness); do \
cat $i;
done
<not supported>
<not supported>
<not supported>
<not supported>
After a bit of testing I finally succeeded in increasing the brightness. Increasing the brightness on the notebook Intel GM965 video card model is done, through file:
/proc/acpi/video/GFX0/DD02/brightness
To see all the brightness levels the Fujitsu LCD display supports:
As you can see the dark screen was caused cause the current: brightness is set to a low value of 25. To light up the LCD screen and make the screen display fine again, I increased the brightness to the maximum level 100, e.g.:
Here is also a tiny program that reduces and increases the notebook laptop brightness written in C. My friend Dido, coded it in just few minutes just for the fun 🙂 To permanently solve the issues with darkened screen on boot time it is a good idea to include echo '100' > /proc/acpi/video/GFX0/DD02/brigthness in /etc/rc.local:
I've also written another Universal Linux Increase laptop screen brightness Shell script which should be presumable also working for all Laptop models running Linux 🙂
I decided to start this post with this picture I found on onlamp.com article called “Simplify Your Life with Apache VirtualHosts .I put it here because I thing it illustrates quite well Apache’s webserver internal processes. The picture gives also a good clue when Virtual Hosts gets loaded, anways I’ll go back to the main topic of this article, hoping the above picture gives some more insight on how Apache works.; Here is how to list all the enabled virtualhosts in Apache on Debian GNU / Linux serving pages:
server:~# /usr/sbin/ apache2ctl -S
VirtualHost configuration:
wildcard NameVirtualHosts and _default_ servers:
*:* is a NameVirtualHost
default server exampleserver1.com (/etc/apache2/sites-enabled/000-default:2)
port * namevhost exampleserver2.com (/etc/apache2/sites-enabled/000-default
port * namevhost exampleserver3.com (/etc/apache2/sites-enabled/exampleserver3.com:1)
port * namevhost exampleserver4.com (/etc/apache2/sites-enabled/exampleserver4.com:1)
...
Syntax OK
The line *:* is a NameVirtualHost, means the Apache VirtualHosts module will be able to use Virtualhosts listening on any IP address (configured on the host), on any port configured for the respective Virtualhost to listen on.
The next output line: port * namevhost exampleserver2.com (/etc/apache2/sites-enabled/000-default
Shows requests to the domain on any port will be accepted (port *) by the webserver as well as indicates the <VirtualHost> in the file /etc/apache2/sites-enabled/000-default:2 is defined on line 2 (e.g. :2).
To see the same all enabled VirtualHosts on FreeBSD the command to be issued is:
freebsd# pcfreak# /usr/local/sbin/httpd -S VirtualHost configuration:
wildcard NameVirtualHosts and _default_ servers:
*:80 is a NameVirtualHost
default server www.pc-freak.net (/usr/local/etc/apache2/httpd.conf:1218)
port 80 namevhost www.pc-freak.net (/usr/local/etc/apache2/httpd.conf:1218)
port 80 namevhost pcfreak.afraid.org (/usr/local/etc/apache2/httpd.conf:1353)
...
Syntax OK
On Fedora and the other Redhat Linux distributions, the apache2ctl -S should be displaying the enabled Virtualhosts.
One might wonder, what might be the reason for someone to want to check the VirtualHosts which are loaded by the Apache server, since this could be also checked if one reviews Apache / Apache2’s config file. Well the main advantage is that checking directly into the file might sometimes take more time, especially if the file contains thousands of similar named virtual host domains. Another time using the -S option is better would be if some enabled VirtualHost in a config file seems to not be accessible. Checking directly if Apache has properly loaded the VirtualHost directives ensures, there is no problem with loading the VirtualHost. Another scenario is if there are multiple Apache config files / installs located on the system and you’re unsure which one to check for the exact list of Virtual domains loaded.
I needed to link a new created WordPress Post to external web page address. So when one clicks over the created post he opens an external website.
I’ve googled around to see how this can be achieved and found ordpress external links plugin I gave a go of the plugin, but pitily I couldn’t make it work. I decided to try some other methods and after some time I tried another approach. I used the HTML >a href=””< My Post Title </a> as a title and it appeared this simple method prooved working 😉
Here is a small screenshot, from wordpress Add New Post dialog
By the way the information online I’ve found on how this the external link creation for a Page or a Post is made was quite obscure and messy. i wonder why there is no clear explanation on the direct a href link creation, especially since WordPress is a de-facto standard for a blogging platform and nowdays powers up so many websites engines around the world.
I needed to convert a file which had a Bulgarian text written in UTF-8 encoding to Windows CP1251 in order to fix a website encoding problems after a move of the website from one physical server to another.
I tried first with enca – ( detects and convert encoding of text files from one encoding to another).
The exact way I tried to convert was:
linux:~# enca -L bg /home/site/www/includes/utf8_encoded_file.php
...
Unfortunately this attempt to conver was unsucesfully, and the second logical guess was to use iconv – Convert encoding of given files from one encoding to another to do the utf8 to cp1251 conversion. I reached for some help in irc.freenode.net, #varnalab channel and Alex Kuklin helped me, giving me an example command line to do the conversion. iconv winedows to cp1251 conversion line, he pointed to me was:
linux:~# iconv -f utf8 -t cp1251 < in > out
Further on I adapted Alex’s example to convert my utf8_encoded_file.php encoded Bulgarian characted to CP1251 and used the following commands to convert and create backups of my original UTF8 file:
I needed to add to a wordpress based website Google maps location pictures with Google Maps Zoom In / Out controls.
I've seen plenty of plugins available that said to to this but none of them really worked fine for me. Either the plugins I checked in wordperss.org was too complex to set up and required a Google API registration or was marked as Broken (not working).
Finally to add the geographic locations taken from maps.google.com I used the embed code generated directly from maps.google.com.
But that was not the end of my WordPress Google Maps struggles. What followed was rather ridiculous, it seems since some time Google removed the pinning of a location searched for. Moreover the easy old way to simply pin a location on the map is also, gone.
Hence here is what I had to do to pinpoint location on the Google map of my searched country destination:
1. To be able to pinpoint the location, I had to login to my gmail 2. Go to http://maps.google.com in browser 3. Press on My Places button 4. Click on Create map and fill in the Title and Description dialogs 5. The Privacy and Sharing radio button should be selected 6. Click on Done and Save buttons 7. From the left top corner inside the Google map image to select the baloon picture (Add a Placemark) 8. Choose the exact desired placemark type and color from the next appearing dialog 9. Choose the location I want to pin on the map
I've created also a small Video tutorial just for fun for all those who want to see the pin a location with a baloon 😉 on the google map tutorial, here is the video as well:
For all people who can't properly see the .mov video here is link to the video created with recordmydesktop on my Linux showing how the baloon pinning inside a map can be done.
I’ve had two domain names which were pointing to the same website content. As one can read in any SEO guide around this is a really bad practice as search engines things automatically there is a duplicate site content and this has automatically a negative effect on the site pagerank. To deal with situation where multiple domains are pointing to the same websites its suggested by many SEO specialists that a 301 redirect is created from all the domain websites to a single website domain which will open the actual website.
Making the 301 direct domain from the sample domain my-redirect-domain.com to www.mydomain.com can be done with a virtualhost dfefinition in either httpd.conf or with the respective file containing the domain virtualhost definitions: Here is the exact VirtualHost code I use to make a 301 redirect.
After placing the VirtualHost redirect, an apache redirect is required. Further on when a Gooogle or Yahoo Bot visits the website and does any request to my-redirect-domain.com or www.my-redirect-domain.com , they will be redirected with a 301 reuturned code to www.mydomain.com
This kind of redirect however can have a negative impact on the Apache CPU use (performance), especially if the my-redirect-domain.com is high traffic domain. This is because the redirect is done with mod_rewrite.
Therefore it might be better on high traffic domains to create the mod_rewrite redirect by using a vhost like:
The downside of using the Apache 301 redirect capabilities like in the above example is that any passed domain urls like let’s say http://www.my-redirected-domain.com/support/ would not be 301 redirected to http://www.mydomain.com/support/ but instead the redirect will be done straight to http://www.mydomain.com/
By the default wordpress does not have support for changing the exact font, therefore copying and pasting a text made in Open Office or MS Word often places in the Post or Page wp edit fonts different from the default one set for articles. Hence some articles after being published on a wordpress blog show up with improper font and the only way to fix that is to change the font first in Open Office and then copy back to wordpress instead of simply being able to change the font from within the wordpress article.
To get around this problem, there is a nice plugin fckeditor-for-wordpress-plugin which aids wordpress with an awesome Word like edit functionalities. , downhload location for FCKEdit for WordPress is here
Here is a screenshot of the extra nice functionality the FCKEditor for wordpress providces.
Installing the plugin is like installing any other wordpress plugin and comes easily to:
debian:/~# cd /var/www/blog/wp-content/plugins
debian:/plugins# wget http://downloads.wordpress.org/plugin/fckeditor-for-wordpress-plugin.3.3.1.zip
...
debian:/plugins# unzip fckeditor-for-wordpress-plugin.3.3.1.zip
...
debian:/plugins# cd fckeditor-for-wordpress-plugin/
And further enabling the plugin from:
Plugins -> Inactive -> (Dean's FCKEditor For WordPress) Enable
fckeditor for wordpress will replace the default wordpress editor TinyMCE straight after being enabled. I’ve done also a mirror of the current version as of time of writting of this article, one can download the fckeditor for wordpress mirrored here Now really file editting inside wordpress admin panel is way easier and convenient 😉 Cheers
The Return Path variable on one of the qmail mail servers I manage was improperly set. New newsletter mails initiated by the php scripts on the mail server had the improper return path set in the mail headers, like so:
Return-Path: <anonymous@mail.mymailserver.com>
Therefore many mail servers dropped messages as the set Return Path variable in the headers was incorrectly set to the domain mail.mymailserver.com
Thus to change the Return Path to the correct one that should have been mymailserver.com I had to include mymailserver.com in qmail’s control file /var/qmail/control/bouncehost, e.g.
I’ve been assigned the task to add on one of the qmail powered servers I administrate about 50 email addresses via command line.
Each email addresses was required to be configured to have the same mail password. Adding the email addresses via an interface would be a killing time consuming task and will probably require at least 1 hour of time to add the emails with qmailwebmin, qadmin, qubit or the other vpopmail qmail web administration interfaces available nowdays.
To solve the task, I’ve used a line oner bash shell script which reads all my 80 emails from a file and adds them with vpopmail’s command line tool vpasswd on the mail server.
Here is the one liner shell script I’ve written to solve the task:
debian:~# while read line; do vadduser $line Email_Pass_Phrase; done < email_list_file.txt
In above’s code I’ve used the email_list_file.txt file is a text file on the server and contains list of all my 50 email addresses, where each line in the file contains one email. The Email_Pass_Phrase is actually the password I’ve set for all the new email addresses being created with vpasswd
That’s all now the 50 email addresses on the server are created and I’ve saved at least one hour of boring repeating actions in the browser 😉
