Every once in awhile I go back and try to figure out how to create a basic ant build.xml file. So I am just placing a sample build.xml here.

The directory structure should be something like
./build.xml
./src/HelloWorld.java

The targets will create the build directory and compile the source and run a test execution of the class.

<project name="HelloWorld" basedir="." default="main">
<target name="clean">
<delete dir="build"/>
</target>

<target name="compile">
<mkdir dir="build/classes"/>
<javac srcdir="src" destdir="build/classes"/>
</target>

<target name="jar" depends="compile">
<mkdir dir="build/jar"/>
<jar destfile="build/jar/HelloWorld.jar" basedir="build/classes">
<manifest>
<attribute name="Main-Class" value="HelloWorld"/>
</manifest>
</jar>
</target>

<target name="run" depends="jar">
<java jar="build/jar/HelloWorld.jar" fork="true" />
</target>

<target name="main" depends="clean,run"/>

</project>

Tags: ant

If you are using perl, you may find it necessary to take some command line arguments to your scripts.  When that time comes, there is a very handy variable ARGV that contains the passed in arguments.

To get the total number of arguments passed into the script you will need to use the following:

$totcommandargs = #$ARGV + 1

is equal to the number of arguments passed in to the Perl script.

Note: you need to add one to the count to get the correct number of variables.

To address the variables you use the following to address the first argument: $ARGV[0]

will address the first argument

Since arrays are addressed by n-1, to get the first element you use 0 {zero}, for the second 1, for the third {2}, and so on.

$0 will give the name of the currently executing script.

#!/usr/bin/perl

$argcount =  $#ARGV +1;
print "The script $0 has $argcount argumentsn";

for( $i = 0; $i < $argcount;$i++)
{
print $ARGV[$i] . "n";
}

If you are using maven to build your projects , then you might have found an out of memory condition in your tests.  Well, setting the MAVEN_OPTS variable with JVM specific options will help with this.

Example:

MAVEN_OPTS=-Xmx1024

Depending on what environment you are in, you will need to set this variable.

This will give the JVM more 1024 megs to work with and you can customize the number to fit your needs.

For the longest time, I thought the “Print Screen” or “PrtScr” Key on my keyboard was a throw back to much older computers with sheet fed dot matrix printers and would just print out the current Dos command shell.

Once I figured out how to use it in windows, it has become an invaluable tool.

I used to create presentations of source code issues. It was a great help to be able to grab a copy of the screen and place it in a Powerpoint slide or Word Doc.

If you need a complete screen capture or even just the current window, here is what you can do.

If you need to capture the complete screen, press the “Print Screen” button located near the top of the keyboard with the scroll lock or Pause key.   It may seem like nothing has happened, but the complete image of your current desktop has been saved into the clipboard in windows.

If you want to just capture the current window, make sure the window you want is active and press the  Alt and “Print Screen” keys together.

Now open Paint, MS Word or any other program capable of handling images, and type Ctrl-V.  This will take the image that has been captured into memory and place it in the program.  Now you can manipulate the image to crop it or use it in your document.

This is a built in function of the MS Windows Operating system.

If you need more control there are other applications that can let you capture portions of the screen at any time and create a file with a simple keystroke, such as SnagIt!

Tags: Utilities

Motorola DCT6412 (Comcast DVR) 30-second skip

I have a Tivo and missed the 30 second skip that was available and I found that the same was available with the Comcast Cable remote.

1) Press the button at the top of the remote to put it into Cable Box control mode.

2) Press and hold the button until the button blinks twice.

3) Type in the code 994. The button will blink twice.

4) Press (do not hold) the button

5) Type in the code 00173 (for 30 second Skip).

6) Press whatever button you want to map the skip, I used the help button as I have never used it myself.

Welcome to 30 second skipping.

I had to send a large file (about 100MB) to a client for analysis.  They did not have an anonymous ftp server so I had to figure a way to e-mail the file to them and then have a way to put it back together.

I found the split command very useful.  I use Linux when I can but have installed Cygwin on my Windows PC to get the same functionality.

Here is a way to break the file into 5 megabyte chunks:

# split -b 8m veryLargeInputFile

This instance splits veryLargeInputFile 8MB segments named xaa xab xac…xap.

Now put the file back together  at the distant end:

# cat xaa xab xac xad xae xaf xag xah xai xaj > veryLargeInputFile

or

# cat * >veryLargeInputFile

Note: ensure xa* are the only files in the directory when using the wildcard
For ASCII files: Split lines — This example splits a document into 1000 line segments.

# split -l 1000 veryLargeTextFile

Use the same process to put the file back together again.

Note: For larger files, find a ftp server or make your filesize increments bigger.

Split options

-b ##   — replace ## with the number of bytes you want in a file

-C ##   — replace ## with the number of SIZE bytes of lines per output file

-l ##     — replace ## with the number of lines per file.

-d          — use numeric suffixes for output files instead of alphabetic

Tags: Utilities