How to rename multiple files at a shell prompt under Linux? The rename command is quite useful.

Rename command usage:

rename oldname newname *.files

Some examples:

Rename all *.abc file as *.xyz:

$ rename .abc .xyz *.abc

Remove .txt file extension:

$ rename 's/\.txt$//' *.txt

Convert all uppercase filenames to lowercase:

$ rename 'y/A-Z/a-z/' *

When buying a wireless router or a wireless network card, have you ever wondered what do these letters next to the protocol 802.11 (a, b, g, and n) really mean? What is the difference between these protocols?

IEEE 802.11 is a set of standards for wireless local area network (WLAN) computer communication. The terms 802.11 and Wi-Fi are often used interchangeably but there is slight difference between the two.

(A) 802.11a
Frequency- 5 GHz  
Typical Data Rate - 23 Mbit/s  
Max Data rate – 54 Mbit/s  
Range – 115 feet

(B) 802.11b
Frequency - 2.4 GHz  
Typical Data Rate - 4.5 Mbit/s  
Max Data rate – 11 Mbit/s  
Range - 115 feet

(G) 802.11g
Frequency - 2.4 GHz  
Typical Data Rate – 19 Mbit/s  
Max Data rate - 54 Mbit/s  
Range – 125 feet

(N) 802.11n
Frequency - 5GHz and/or 2.4GHz  
Typical Data Rate - 74 Mbit/s  
Max Data rate - 300 Mbit/s (2 streams)
Range – 230 feet

Backing up via the command line:

Type the following at the prompt with the appropriate USERNAME and DATABASE name:

mysqldump -u USERNAME -p DATABASE > dump.sql

You will be prompted for your database password and then the DATABASE will be dumped to a plain-text file called dump.sql.

Restoring via the command line:

First drop and recreate the database as needed:

Drop the database

mysqladmin -u USERNAME -p drop DATABASE

Recreate the database

mysqladmin -u USERNAME -p create DATABASE

Import the backup data

mysql -u USERNAME -p DATABASE < dump.sql

Here is how to setup JAVA_HOME and PATH environment variables for a single user or all users on Fedora Linux system

Setting JAVA_HOME and PATH for a single user

# vi ~/.bash_profile
# export JAVA_HOME=/opt/jdkx.x.x_xx
# export PATH=$PATH:$JAVA_HOME/bin

Setting JAVA_HOME and PATH for all users

# vi /etc/profile
# export JAVA_HOME=/opt/jdkx.x.x_xx
# export PATH=$PATH:$JAVA_HOME/bin

Here are three quick ways to find out which shell you are currently using:

Method 1:

command:

# echo $SHELL

output:

/bin/bash

Method 2:

command:

# echo $0

output:

-bash

Method 3:

command:

# ps -p $$

output:

 PID TTY               TIME CMD
1447 tty1          00:00:01 bash

Windows Vista supports symbolic links (soft links). One way of creating these links is using the command line utility called MKLINK.

Run Command Prompt and type the comman MKLINK.

If the system warns saying…“You do not have sufficient privilege to perform this operation”. Run the Command Prompt as Administrator

Usage:

MKLINK [[/D] | [/H] | [/J]] Link Target
        /D      Creates a directory symbolic link.  Default is a file
                symbolic link.
        /H      Creates a hard link instead of a symbolic link.
        /J      Creates a Directory Junction.
        Link    specifies the new symbolic link name.
        Target  specifies the path (relative or absolute) that the new link
                refers to.

Example: To create a directorty link called src what points to c:\users\foo\src

     mklink /D src c:\users\foo\src
Thats it!

Twitter

Twitter is a free social networking and micro-blogging service that allows users to send updates (otherwise known as tweets) which are text-based posts of up to 140 characters in length.

Pownce

Tumbler

Jaiku

The following sample code works well with Java 1.5 and Apache Commons Net 1.4.1

import org.apache.commons.net.ftp.*;
...
boolean ftpTransfer(String localfile, String destinationfile)
{
	String server = "ftp.domain.com";
	String username = "ftpuser";
	String password = "ftppass";
	try
	{
		FTPClient ftp = new FTPClient();
		ftp.connect(server);
		if(!ftp.login(username, password))
		{
			ftp.logout();
			return false;
		}
		int reply = ftp.getReplyCode();
		if (!FTPReply.isPositiveCompletion(reply))
		{
			ftp.disconnect();
			return false;
		}
		InputStream in = new FileInputStream(localfile);
		ftp.setFileType(ftp.BINARY_FILE_TYPE);
		boolean Store = ftp.storeFile(destinationfile, in);
		in.close();
		ftp.logout();
		ftp.disconnect();
	}
	catch (Exception ex)
	{
		ex.printStackTrace();
		return false;
	}
	return true;
}
 

A step towards making TextPad a lightweight IDE. Using the trick below, you can compile your code using Ant from inside TextPad. Click on the error messages and jump to the source file and the problematic line of code.

1. First, make sure you can compile from the command line using Ant
2. In Textpad, go to Configure-> Preferences-Tools.
3. Click on the Add button and select the Dos Command option
4. Enter ant -find in the edit box and press OK to dismiss the dialog box.
5. Now press the Apply button
6. In the left pane, expand Tools and highlight ant -find
7. In the right pane, select capture output and save all documents first options
8. Enter the following Reguar Expression ^[ \t]+\[javac\] \([A-Za-z]:[^:]+\):\([0-9]+\):
9. Set File to 1 and Register to 2

All done. To run Ant, select it from the “Tools” menu. The build.xml file should be in the same directory, or in any ancestor directory.