Calendar (cal) on Linux command line

Sometimes it feels that many of the excellent and convenient command-line tools is forgotten, when they are replaced by graphical tools. A good example is the cal program, which is a command-line calendar to Linux and UNIX. It displays a simple calendar in text format. Cal usage Displays current month calendar on console cal Output: October 2009 Su Mo Tu We Th Fr Sa 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 Displays selected month and year calendar on console cal 11 2012 Output:
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Postgresql (psql) .psqlrc tips and tricks

Psql is a good tool for the PostgreSQL database management and use. Psql client functioning can easily be improved by adding a few lines ~/.psqlrc file.

  1. Tuning psqlrc 1.1 Set all null fields to NULL: \pset null 'NULL' After this, the query results look like this: select 'test' as test_text, null as test_null; test_text | test_null ———–+———– test | NULL (1 row) 1.2 Set the command history file names for each host and database: \set HISTFILE ~/.
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Prevent the browsers to use old cached CSS and JS files

Browser cache is very useful when users download the same CSS and JS files multiple times. Some browsers, however, use the old CSS and JS files from the cache, even though they have been updated. This may lead to unpleasant situations, when the pages are displayed to the user with the wrong styles or pages will work incorrectly. Fortunately, these unpleasant situations is easy to avoid and let the browsers cache files as long as they are changed.
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CSS compression with own PHP class VS CSSTidy

It makes sense to optimize the site’s cascading style sheets (CSS), as it pages load faster, and it reduce the amount of data transferred, and just combining css files could significantly reduce requests to server. So users benefit from faster page loads and webmaster of the sites benefits from the cheaper price of the transferred data. I have used CSSTidy on many projects. And CSSTidy is very good tool for packing CSS and it can even fix CSS errors.
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Linux Tip: How to handle a files with a dash as first character from command line

Sometimes you maybe have to handle files with a dash (-) as first character from Linux command line. It can be difficult, because the script “thinks” the marks after the dash are parameters. So files which name begins with dash (-) can not be dealt with directly by typing the command and the file name, such as the following: less -file-with-a-dash-as-first-character Files which name begins with dash (-) can be used as follows:
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Google search from Linux and UNIX command line

Today I started thinking that how cool is do some Google searches straight from command line. First I try to find some ready tricks from the Internet, but I couldn’t find quickly anything good. So I decide do a simple Bash function that can take Google search as parameter and open Firefox Browser (tab) with Google search. Sounds easy… :) First we need Google search URL without search parameter and it looks like this:
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Add date and time to Linux terminal title (Gnome Terminal, xterm, urxvt, rxvt)

Here is easy way add date and time to Linux terminal title. This trick works at least following terminals Gnome Terminal, xterm, urxvt, rxvt. Simply type the following command line: while sleep 1 ; do echo -ne '\033]2;'date'\007'; done &
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Fedora 12 Constantine is released

Fedora team promises to bring to you the latest and greatest release of Fedora ever, Fedora 12! Many things are really changed and improved. Fedora 12 also brings lots of new packages. Here is some highlights from Fedora 12 new stuff Optimized performance – 32-bit architecture software packages have been compiled with special optimization for the Intel Atom processors without losing compatibility with the overwhelming majority of CPUs. Smaller and faster updates – Fedora 12 uses yum-presto plugin as default.
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Howto upgrade Fedora 11 to Fedora 12 with Preupgrade

I think the most easiest way to upgrade Fedora 11 to Fedora 12 is program called preupgrade, which download needed packages from the server and then just reboot to installer and after install boot the new system. Of course it’s important backup your important files before upgrading. Commands and screenshots of whole upgrading process First start with updating all Fedora 11 packages with following command as root yum update Install preupgrade as root yum install preupgrade Start preupgrade as root preupgrade Preupgrade information window Choose desired release Preparing system for upgrade Downloading files Prepare and test upgrade When ready to begin upgrade then reboot.
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Hide Apache ServerSignature / ServerTokens / PHP X-Powered-By

By default almost all Apache installation shows sensitive server information with Apache version number, server operating system details, installed Apache modules, PHP-version and so on. Attackers can use this information when performing attacks. Some examples howto check server information that Apache sends Error page Use lynx $ lynx -head -mime_header http://www.ubuntu.com HTTP/1.0 200 OK Date: Fri, 20 Nov 2009 09:25:46 GMT Server: Apache/2.2.8 (Ubuntu) mod_python/3.3.1 Python/2.5.2 PHP/5.2.4-2ubuntu5.7 with Suhosin-Patch mod_ssl/2.
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Fedora 13 nVidia Drivers Install Guide (disable the nouveau driver)

Looking Fedora 22/21 nVidia Drivers Install Guide? I’ve tried this method in few Fedora 12 and Fedora 13 machine, and looks like it is working. Nouveau has been enabled by default starting from Fedora 11 and looks like nouveau cause some problems on Fedora 12 and Fedora 13, when try to use nVidia proprietary driver. Note: nVidia proprietary drivers on Fedora 12 and Fedora 13 does not support older cards than GeForce 6 cards (except for some exceptions, check this comment).
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Partitioning PostgreSQL Tables - Handle Millions of Rows Efficiently

PostgreSQL table partitioning means splitting one large database table into smaller logical pieces. PostgreSQL table partitioning will be worthwhile only when a table would be very large. Here are a few benefits of what can be achieved with partitioning: Large tables query performance can be improved dramatically Reducing index size and making it more likely that the heavily-used parts of the indexes fit in memory Rarely used data can be moved to slower and cheaper storage media This topic is divided into three parts, which are as follows and published in the following order: Part 1.
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Create PostgreSQL Table Partitioning (Part 1)

PostgreSQL supports partitioning via table inheritance. So the partitioning is made in such a way that every child table inherits single parent table. Parent table is empty and it exists just to describe the whole data set. PostgreSQL partitioning can be implemented in range partitioning or list partitioning. Range partitioning can be done for example by ID ranges (like 0-100 000, 100 001-200 000, 200 001-300 000…) or Date ranges (like 2009-11-01 – 2009-11-30, 2009-12-01 – 2009-12-31…).
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PHP Script to Generate PostgreSQL Table Partitioning (Part 2)

As Part 1 (Howto create PostgreSQL table partitioning) shows, making of PostgreSQL partitioning needs a lot of SQL commands. So this Part 2 explains how SQL commands for PostgreSQL partitioning can be made with a simple PHP script. This example script make SQL for child tables, indexes, trigger function and parent table trigger. This example script can make PostgreSQL table partitioning with using Date ranges. Script can be configured with following configuration section:
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PHP: Loop through dates (from date to date) with strtotime() function

This is very easy way loop through dates (from date to date) with PHP strtotime() function. This example only echo dates, but of course this model can be used more complicated situations. <?php // Set timezone date_default_timezone_set('UTC'); // Start date $date = '2009-12-06'; // End date $end_date = '2020-12-31'; while (strtotime($date) <= strtotime($end_date)) { echo "$date\n"; $date = date ("Y-m-d", strtotime("+1 day", strtotime($date))); } Note: All different PHP strtotime() function syntaxes can be used.
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PostgreSQL: Partitioned Table vs Non Partitioned Table (Part 3)

This article compares the speed and performance of queries between partitioned and non partitioned PostgreSQL tables. However, it is important to remember that the PostgreSQL tables partitioning has also another benefits, than the better performance on queries. More information about other benefits from the first part ‘Howto create PostgreSQL table partitioning (Part 1)‘. This is comparision between partitioned and non partitioned PostgreSQL tables. The same tests were carried out with and without indices, because using the indices, it is no longer very meaningful example on table, which has one billion rows of data (if the table is not partitioned).
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Format bytes with PHP – B, KB, MB, GB, TB, PB, EB, ZB, YB converter

Simple PHP function that formats the bytes to the desired form. Possible unit options are: Byte (B) Kilobyte (KB) Megabyte (MB) Gigabyte (GB) Terabyte (TB) Petabyte (PB) Exabyte (EB) Zettabyte (ZB) Yottabyte (YB) PHP byteFormat function for formatting bytes Function takes three parameter: (bytes mandatory, unit optional, decimals optional) <?php function byteFormat($bytes, $unit = "", $decimals = 2) { $units = array('B' => 0, 'KB' => 1, 'MB' => 2, 'GB' => 3, 'TB' => 4, 'PB' => 5, 'EB' => 6, 'ZB' => 7, 'YB' => 8); $value = 0; if ($bytes > 0) { // Generate automatic prefix by bytes // If wrong prefix given if (!
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Delete files permanently with shred command in Linux – Remove absolutely

Sometimes we need to delete files which content should disappear absolutely, completely and safely. Linux command rm just remove file and it’s still possible to dig out from the disk. Fortunately for Linux can be found in shred program that removes the files permanently. Shred command is easy and quickly to use cases when files need to deleted forever. Shred command usage Create test file: echo "testing testing" > /tmp/test.
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Twitter Hacked by Iranian Cyber Army

Twitter site is hacked by Iranian Cyber Army. Here is some screenshots and full info about page. Screenshots Server info and full html content lynx -mime_header http://twitter.com HTTP/1.1 200 OK Date: Fri, 18 Dec 2009 06:42:08 GMT Server: Apache/2.2.14 (Unix) mod_ssl/2.2.14 OpenSSL/0.9.8l DAV/2 mod_auth_passthrough/2.1 FrontPage/5.0.2.2635 Last-Modified: Fri, 18 Dec 2009 06:21:13 GMT ETag: "90c06a-717-47afabf13c840" Accept-Ranges: bytes Content-Length: 1815 Connection: close Content-Type: text/html <meta content="en-us" http-equiv="Content-Language"></meta> <meta content="text/html; charset=windows-1252" http-equiv="Content-Type"></meta> <title>..:: This Web Site Has Been Hacked By Iranian Cyber Army ::.
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Twitter hacked? Not really, only Twitter DNS records compromised

I before post ‘Twitter Hacked by Iranian Cyber Army’, but actually just Twitter DNS records was hacked. I think even twitter.com server headers and tracepath to servers simply prove this, because they are completely different normally when hacked. Hacked twitter.com headers: HTTP/1.1 200 OK Date: Fri, 18 Dec 2009 06:42:08 GMT Server: Apache/2.2.14 (Unix) mod_ssl/2.2.14 OpenSSL/0.9.8l DAV/2 mod_auth_passthrough/2.1 FrontPage/5.0.2.2635 Last-Modified: Fri, 18 Dec 2009 06:21:13 GMT ETag: "90c06a-717-47afabf13c840" Accept-Ranges: bytes Content-Length: 1815 Connection: close Content-Type: text/html Original twitter.
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