ionutb - tech & more: June 2011

Wednesday, June 29, 2011

Monday, June 27, 2011

MySQL: Check, repair and optimize tables (all tables, all databases)

MySQL check, repair or optimize:
- all tables in a databases
- all tables from all databases
- a certain table

Check tables for all databases:

$ mysqlcheck -u root -p -v --all-databases

Check tables for a certain database:

$ mysqlcheck -u root -p -v db_name

Optimize table:

$ mysqlcheck -u root -p -v --optimize db_name table_name

Repair table:

$ mysqlcheck -u root -p -v --repair db_name table_name

Auto-repair tables:

$ mysqlcheck -u root -p -v --auto-repair db_name

Linux - rm - Argument list too long - Solution

When deleting too many files in one directory using rm the following error can appear: "rm: Argument list too long".

Problem:

$ rm *

bash: /bin/rm: Argument list too long

Solution:

$ find ./ -name "*file_name_part*" -delete

Twitter Advertising, next step

Twitter is looking to introduce more advertising, targeting its most active sections: Twitter plans bolder advertisements

Sunday, June 26, 2011

Ubuntu convert VOB to AVI

How to convert VOB to AVI in Ubuntu:
ffmpeg -i video.vob -sameq new-video.avi

Thursday, June 16, 2011

FaceBook is loosing customers in U.S., Canada and other countries

FaceBook is loosing users in countries it was first established.
For the month of May: - 6 mil. users in U.S. (from 155.2 mil. to 149.4 mil.), - 1.52 mil. users in Canada (to 16.6 mil.), - 100.000 users each in U.K., Norway, and Russia.
Overall, the total number of FaceBook users increased by 1.7% driven by growth in other countries (Brazil, Mexico, etc).
The reasons are multiple:
- too much noise on the network
- privacy issues and concerns
- constant bombardment with unsolicited material
- aggressive way of introducing new features
...

Wednesday, June 15, 2011

Google Voice Search available on personal computers

Google Voice Search available on personal computers, laptops, mobile phones and any other devices.
For laptop/PC the only requirements in order to use Google Voice Search are Google Chrome Web Browser and a microphone of course. More about this:
http://googleblog.blogspot.com/2011/06/knocking-down-barriers-to-knowledge.html

Google Instant Pages, under Chrome

After performing a Google Search, from the results displayed, Google makes a "guess" about which result you will click. Based on this "guess", only when you are using Google Chrome Web Browser, Google "prerenders" (preloads) the page you are about to click on. The result: when you click on that result, the target site loads instantly.
More info:
http://googlewebmastercentral.blogspot.com/2011/06/announcing-instant-pages.html
http://blog.chromium.org/2011/06/prerendering-in-chrome.html

Tuesday, June 14, 2011

Bursa de domenii

InfoDomenii.ro :: Cumpara si vinde domenii pe bursa de domenii. Gaseste parteneri pentru reclama web. Promoveaza-ti serviciile si afacerea.

Monday, June 13, 2011

Javascript: Automatically adjust iframe height to fit content

This solves the need to adjust the height of an iframe depending on the length of the content inside the iframe. The iframe may contain images, text, etc.

This solution is also appropiate for the situations when you have a form inside an iframe and the number of the fields of the form changes dynamically (javascript) depending on user actions. Also the display of form errors above the form may be a cause for content stretching over the predefined height of the iframe.

Technical description: The height of the iframe's content is read from inside the iframe and a function from the parent window is called in order to modify the height.

File 1, dynamic-height-adjusting-iframe.html :

<html>
<head>
<title>read element height</title>
<script type="text/javascript">
function adjustIframeHeight(_h) {
var new_h = _h + 50;
document.getElementById('my_iframe').style.height = new_h + 'px';
}
</script>
</head>

<body>

<div>
Other text here<br/>
Other text here<br/>
Other text here.<br/>
</div>

<iframe id="my_iframe" src="dynamic-height-adjusting-iframe-content.html" width="730" height="650" scrolling="no" frameborder="1" marginwidth="0" marginheight="0" style="border-top:2px solid #ccc;border-left:2px solid #ccc;border-right:2px solid #ddd;border-bottom:2px solid #ddd;"></iframe>

</body>
</html>

File 2, dynamic-height-adjusting-iframe-content.html :

<html>
<head>
<title>read element height</title>
<script type="text/javascript">
function getXYpos(elem) {
   if (!elem) {
      return {"x":0,"y":0};
   }
   var xy={"x":elem.offsetLeft,"y":elem.offsetTop}
   var par=getXYpos(elem.offsetParent);
   for (var key in par) {
      xy[key]+=par[key];
   }
   return xy;
}
function getHeightBetweenElements(elem1, elem2) {
   var xy1 = getXYpos(elem1);
   var xy2 = getXYpos(elem2);
   return xy2.y - xy1.y;
}
function adjustMySelf() {
   var h = getHeightBetweenElements(document.getElementById('pos-reper1'), document.getElementById('pos-reper2'));
   parent.adjustIframeHeight(h);
}
</script>
</head>

<body>
<div id="pos-reper1"></div>

<div style="width: 300px; margin: 0 auto;">
text sakfjdsio fdiojsifojdsio fjdiojs fds
text sakfjdsio fdiojsifojdsio fjdiojs fds
text sakfjdsio fdiojsifojdsio fjdiojs fds
text sakfjdsio fdiojsifojdsio fjdiojs fds
text sakfjdsio fdiojsifojdsio fjdiojs fds
text sakfjdsio fdiojsifojdsio fjdiojs fds
text sakfjdsio fdiojsifojdsio fjdiojs fds
text sakfjdsio fdiojsifojdsio fjdiojs fds
text sakfjdsio fdiojsifojdsio fjdiojs fds
text sakfjdsio fdiojsifojdsio fjdiojs fds
</div>

<div id="pos-reper2"></div>

<script type="text/javascript">
adjustMySelf();
</script>
</body>
</html>

Javascript: Read element height containing dynamic text

Read the height of any DOM element (paragraph, div, etc) which doesn't have a height predefined and contains dynamically generated text (variable length content).

Example, file read-element-height.html :

<html>

<head>

<title>read element height</title>

function getXYpos(elem) {

if (!elem) {

return {"x":0,"y":0};

}

var xy={"x":elem.offsetLeft,"y":elem.offsetTop}

var par=getXYpos(elem.offsetParent);

for (var key in par) {

xy[key]+=par[key];

}

return xy;

}

function getHeightBetweenElements(elem1, elem2) {

var xy1 = getXYpos(elem1);

var xy2 = getXYpos(elem2);

return xy2.y - xy1.y;

}

</script>

</head>

<body>

Other text here<br/>

Other text here.

text sakfjdsio fdiojsifojdsio fjdiojs fds

</div>

</div>

<div>

Height of the dynamic text box (between 'pos-reper1' and 'pos-reper2') is:

var h = getHeightBetweenElements(document.getElementById('pos-reper1'), document.getElementById('pos-reper2'));

document.write(h + 'px');

</script>

</div>

<div>

Adjusting container height and adding extra 50px...

var h_container = h + 50;

document.getElementById('container').style.height = h_container + 'px';

document.getElementById('container').style.backgroundColor = 'PaleGoldenrod';

</script>

</div>

</body>

</html>

Sunday, June 12, 2011

Scroll parent window from child iframe

Scroll parent window to top, from child iframe:

Thursday, June 9, 2011

Exclude directories from TAR archive - CACHEDIR.TAG file

Prevent TAR from archiving directories of your choice. Add the file CACHEDIR.TAG in the directory you don't want it to be archived, with the following content:

$cat CACHEDIR.TAG

Signature: 8a477f597d28d172789f06886806bc55

# marked as cache in order to be excluded from scheduled backup

Linux - change default editor (usually `vi`) - set new editor: `mcedit`

To change the default editor (for commands like `crontab -e`), run:
export VISUAL='mcedit'
export EDITOR='mecedit'

Both above lines should be added to ~/.bashrc in order to keep this setting permanent.

Change default editor in MC (Midnight Commander):
In mc menu select: Options -> Configuration -> use internal edit

Monday, June 6, 2011

Grant DELETE MySQL

GRANT DELETE ON `db_name`.`table_name` TO 'user'@'localhost';