In each language that I have learned I have found it useful to know how to process command line arguments and here is a simple framework that I use for Java. I usually wrap the java command line in a bat or shell file to make it easier to run so that the user does not have to worry about classpath or path issues.

The following is the basic code to handle the command line arguments.

class CmdArgs
{

  public static void main(String[] args)
  {
      int argsize = args.length;
      String curarg;

      if (argsize > 0 )
      {
       
      }
      
      for(int i = 0; i < argsize; i++)
      {
          if (args[i].equals("--host"))
          {
             i++;
             host = args[i];
           }
          else if (args[i].equals("--debug"))
          {
               debug = 1;
          }
          else
          {
              System.out.println("Unknown option: " + args[i]);
              System.exit(1);
          }
       }

   }
}

The bat file for Dos/Windows might look like this:

@echo off

java -cp c:javabin;somejar.jar  com.etechtips.CmdArgs %*

The shell based file might look like:

java -cp /home/ecdown/javabin:somejar.jar com.etechtips.CmdArgs $*

Tags: Java, Scripts

I use find and grep quite a bit. I found that I was regularly searching for strings in file and was typing commands like:

find . -exec grep "somestring" {} ; --print

This find command will search from the current directory and for each file will run grep on it and if it finds a matching string, it will print the string and then the filename. So I took this and moved it into a script.

#!/bin/sh

if [ $# -lt 1 ]; then
  echo 1>&2 Usage: $0 ""
  exit 127
fi
icase=
search=

while [ $# -ge 1 ]; do
  case $1 in
     -i) icase=$1;;
      *) search=$1 ;;
  esac
  shift
done

find . -type f -print0 | xargs -0 grep $icase $search

This allows me to run a command such as

ffind -i Super

This command will search all file names starting from the current directory and recurse directories and the “-i” will tell it to ignore case.

Tags: scripting

There are times that I get on a Linux box and want to know about some of the resources available to me. There are tools that can accomplish this, but there are some files that contain basic settings about the resources available to the system. One of those file is:

/proc/cpuinfo

This file contains information about the Processors and you can do a simple:

more /proc/cpuinfo

to see all the details or you can grep for certain fields:

processor       -- This will show you how many processor entries there are.
cpu MHz  or MHz -- This will show you the speed of the processors.
cache size      -- This will show you the cache size available to the processor.
model           -- This will show you the type and model of the processor you are using.

There are quite a few more fields, but these are the ones that I check the most.

Tags: Linux, processor, Utilities

When I am editing and having a “clumsy fingers” day, I find that I have to reload the file that I am editing from disk repeatedly. I usually just do a quick “:q!” and re-run the vi command that opened the file. But there is a better way!

Use the :edit command:

:edit

Or you can shorten it to

:e

Now if you have typed in the window you are editing and want to reload from disk anyway without saving, remember to add the exclamation point(!) to the command.

:edit!

or

:e!

Tags: editors, utilitie, vi

When you are typing in the location bar, you can have the suggestions come from your History, Bookmarks, Both or none.

To update this, Goto Tools->Options.

In the popup menu, select the privacy tab.

At the bottom there is the Location bar section. Select the “When using the location bar, suggest:

History and Bookmarks  
History
Bookmarks
Nothing

Tags: Browsers, Firefox

These are the individual background properties in CSS.

background-color
background-image
background-repeat
background-attachement
background-position

The background-color property specifies the color of the element. This can be useful to specify if someone has turned images off and you want a non-default view of your content. You can use a hex value (#RRGGBB), a shortcut hex value (#RGB) or a named color (red, green,blue).

background-color: #fffffff;

The background-image specifies an image to place in the background of an element. Remember that the image should be supported by as many browsers as possible. This means using jpeg, pngs or gifs, not tifs or proprietary image formats.

background-image: url(images/someimage.gif)

The background-repeat property specifies how an image should display within an element. You can have it repeat across (repeat-x), repeat downwards (repeat-y) or not repeat (no-repeat).

background-repeat: repeat-x;

The background-attachmemnt attribute is used to specify if an image should scroll (scroll) with the page, be fixed (fixed) to the page or inherit position from a parent element (inherit).

background-attachment: fixed;

The background-position attribute is used to specify the starting position of an image. This can be useful if you are using a sprite to speed up loading times. The background-position attribute can take a Xpx Ypx argument, an X% Y% argument, named arguments(left top, right bottom,…) or inherit from the parent.

background-position: 50% 50%;

Here is an example of the use of these:

 body {
   background-color: #ffffff;
   background-image: url(images/someimage.gif);
   background-repeat: no-repeat;
   background-attachment: fixed ;
   background-position: left top ;
}

You can also use a short cut method to the background property.

 .imagebox {
  background: #ffffff url(images/someimage.gif) no-repeat fixed right top;
}

Tags: CSS, html, properties

I was tracking a log file the other day and had to reload the file from disk regularly so I wanted to find out how to make a shortcut key to the Reload from disk menu entry on the File menu. Using the Settings->Shortcut Mapper to update the shortcuts for a given menu entry, I chose the Ctrl-R sequence but you are welcome to find an unmapped key sequence that works for you.

So I lost my hard drive and went to play some of the videos that I have saved on the system and could no longer play them in Windows Media Player. I needed to download a set of video codecs to play my .vob files. I am using the K-Lite Codec Pack.

Featured Software

VIDEO CODECS
FFDShow MPEG-4
DivX 8
Koepi’s XviD Codec
DScaler MPEG Filters
Ogg Codecs
Xvid Video Codec
Nic’s XviD Codec
Ligos Indeo Codec
AUDIO CODECS
MPEG Layer-3 Codec
AC3 Filter
AC-3 ACM Codec
CoreVorbis Decoder
LAME DirectShow Filter
LAME MP3 Encoder
Monkey’s Audio
Vorbis Ogg ACM Codec

This allows me to view the files in other video apps as well.

Tags: Video, Windows

I regularly have to process Comma Seperated Value or CSV files, usually for user lists. So the following perl code is a framework for processing a file line by line.

#!/usr/bin/perl
use strict;
my $line;

open(FILEIN, "filename.txt");

while(<FILEIN>)
{
  chomp();
  $line = $_;
  # Process $line for data
  # Example seperating line by commas: 
  my ($username,$firstname,$lastname,$email) = split(/,/,$line);
}

close(FILEIN);

Tags: perl, scripting

Here are some basics about Perl hashes that can be helpful to be used when an you need to associate a label with some value such as for names and telephone numbers or account numbers with amounts owed.

Create a hash variable.

my %hashvar;

Create a hash reference

my $refhash = {};

Add a value to a hash variable.

$hashvar{'somekey'} = 'someval';

Add a value to a hash reference.

$hashref->{'somekey'} = 'someotherval';

Access a value in a hash.

print $hashvar{'somekey'};

Access a value in a hash reference.

print $hashref->{'somekey}';

Access all Keys in a hash variable.
foreach my $k (keys(%hashvar))
{
print $hashvar{$k};
}

Access all Keys in a hash reference.

foreach my $k (keys(%$hashref))
{
  print $k . "n";
}

Access all Keys and values in a hash.

while (my ($key,$value) = each %hashvar)
{
  print "Key: " . $key . " has value:" . $value . "n";
}

Access all Keys and values in a hash.

while (my ($key,$value) = each %$refhash)
{
  print "Key: " . $key . " has value:" . $value . "n";
}

Assigning multiple values to a hash

%hasvar = (
  'test2' => 'myval',
  'test3' => 'myval3'
);

Note: This will clear the existing hash.

Delete a value from a hash

delete $hashvar{'key1'};

Delete a value from a hash reference.

delete $hashref->{'key1'};

Tags: hash, perl, scripting, Utilities