Monthly Archives: March 2010
Drop MySql database
We can drop a mysql database using mysqladmin. A root user or user with special privilege to create or to delete a MySQL database can perform this operation. Here is an example to delete a database: [root@host]# mysqladmin -u root … Continue reading
Create MySql Database using mysqladmin
A root user or user with enough privileges can create any database using mysql mysqladmin binary. Here is a simple example to create database called w3m: [root@host]# mysqladmin -u root -p create w3m Enter password:****** This will create a MySQL … Continue reading
Connect to MySQL server from command prompt
Here is a simple example to connect to MySQL server from command prompt: [root@host]# mysql -u root -p Enter password:****** This will give you mysql> command prompt where you will be able to execute any SQL command. Following is the … Continue reading
Adding MySQL User Accounts
For adding a new user to MySQL you just need to add a new entry to user table in database mysql. Below is an example of adding new user guest with SELECT, INSERT and UPDATE privileges with the password guest123 … Continue reading
Run and shut down MySQL Server
Check if your MySQL server is running or not. You can use following command to check this: ps -ef | grep mysqld If your MySql is running then you will see mysqld process listed out in your result. If server … Continue reading
Check mysql server status using mysqladmin utility
Use mysqladmin binary to check server version. This binary would be available in /usr/bin on linux and in C:\mysql\bin on windows. [root@host]# mysqladmin –version It will produce following result on Linux. It may vary depending on your installation: mysqladmin Ver … Continue reading
Installing MySQL on Windows
MySQL now comes neatly packaged with an installer. Simply download the installer package, unzip it anywhere, and run setup.exe. Default installer setup.exe will walk you through the trivial process and by default will install everything under C:\mysql. Test the server … Continue reading
Installing MySQL on Linux/Unix
The recommended way to install MySQL on a Linux system is via RPM. MySQL AB makes the following RPMs available for download on its web site: MySQL – The MySQL database server, which manages databases and tables, controls user access, … Continue reading
Strip out leading whitespace in perl
The code in the example removes leading whitespace from the text of the here document. The /m modifier lets the ^ character match at the start of each line in the string, and the /g modifier makes the pattern matching … Continue reading
Interpolating functions and expressions in perl strings
We can construct more complex templates with scalar variable and function interpolation. Developers generally want a function call or expression to expand within a string. You can break up your expression into distinct concatenated pieces: $endresult = $varone . funccall() … Continue reading
Capitalize each word first character, downcase other characters.
$text = "thIS is a loNG liNE"; $text =~ s/(\w+)/\u\L$1/g; print $text; This Is A Long Line
Convert uppercase string to lowercase in Perl
We can use the lc and uc functions or the \L and \U string escapes to convert between upper and lower case in Perl. use locale; # needed in 5.004 or above $upper = uc($lower); # "hello" -> "HELLO" … Continue reading
Primitive data types in java
There are eight primitive types of data in java: byte, short, int, long, char, float, double, and boolean. They are broadly classified as: Integers – byte, short, int, and long Floating-point – float and double. Characters Boolean Byte The smallest … Continue reading
Command to execute java jar application
To run an application packaged as a JAR file we require the Main-class manifest header. The command is: java -jar app.jar
Run an applet packaged as a JAR file
<applet code=AppletClassName.class archive="JarFileName.jar" width=width height=height> </applet>
Generate random numbers in perl
We can use perl’s rand function to generate random numbers. This code generates and prints a random integer between 15 and 45, inclusive: Usage: $random = int( rand( $Y-$X+1 ) ) + $X; Example: $random = int( rand(31)) + 15; … Continue reading
JAR file operations in Java
Operation Command To create a JAR file jar cf jar-file input-file(s) To view the contents of a JAR file jar tf jar-file To extract the contents of a JAR file jar xf jar-file To extract specific files from a JAR … Continue reading
Reserved keywords in Java
abstract assert boolean break byte case catch char class const continue default do double else enum extends final finally float for goto if implements import instanceof int interface long native new package private protected public return … Continue reading
Perl Roman numerals and Arabic numerals
We can use the Roman module from CPAN. The Roman module provides both Roman and roman for converting Arabic (“normal”) numbers to their Roman equivalents. Roman produces uppercase letters, whereas roman gives lowercase ones. use Roman; $roman = roman($arabic); # … Continue reading
Perl decimal to binary
To convert a Perl integer to a text string of ones and zeros, first pack the integer into a number in network byte order* (the N format), then unpack it again bit by bit (the “B32″ format). sub dec2bin { … Continue reading
