LCD text in NetBeans

Finally figured out how to enable sub-pixel rendering (also known as LCD text) in NetBeans. Just add -J-Dawt.useSystemAAFontSettings=lcd to netbeans_default_options variable in your ~/.netbeans/6.1/etc/netbeans.conf

Bash Random Shuffle

Here is a bash function which returns a random permutation of the input lines of text.

#****f* shadegrowncode/randomShuffle
# NAME
#   randomShuffle - prints random permutation of lines in standard input
# FUNCTION
#   Prints all or the first N lines of a random permutation of the
#   lines of standard input. The random permutation is obtained using
#   Durstenfeld shuffle algorithm. Performance is O(N) in memory and
#   CPU.  Limit the input to 32768 lines or rewrite using a different
#   random generator.
# SEE ALSO
#   http://en.wikipedia.org/wiki/Knuth_shuffle
# PARAMETERS
#   * 1 - (optional) return only the first N of the random lines of input
# SOURCE
function randomShuffle
{
    typeset -a elements
    typeset length=0
    while read line
    do
        elements[$length]=$line
        length=$(($length + 1))
    done
    typeset firstN=${1:-$length}
    if [ $firstN -gt $length ]
    then
        firstN=$length
    fi
    for ((i=0; $i < $firstN; i++))
    do
        randPos=$(($RANDOM % ($length - $i) ))
        printf "%s\n" "${elements[$randPos]}"
        elements[$randPos]=${elements[$length - $i - 1]}
    done
}
#***

Usage examples:
Print three random users from the password file:

$ cut -d: -f1 /etc/passwd | randomShuffle 3
sync
sysadmin
vcsa

Print a random permutation of digits:

$ echo $(printf "%s\n" 0 1 2 3 4 5 6 7 8 9 | randomShuffle)
4 1 0 6 8 7 2 5 3 9

Volkerding says KDE4 better than MacOS

Patrick Volkerding (Slackware Project Lead) gives glowing thumbs up to KDE4 and slates it for inclusion into Slackware 14. Slackware is currently at version 12 and releases once a year. At this rate, KDE4 will be in Slackware in 2009. Among other things, Patrick says the following.

The look of the new [KDE] desktop is stunning, and the use of SVG and hardware acceleration gives (IMHO) even something like MacOS a run for its money in terms of appearance and user-friendliness. We look forward with great anticipation to merging KDE4 when it is mature enough (and it's getting there fast), and then watching it just get better and better.

The full quote can be found in Slackware ChangeLog.

Reason to switch to Linux #11

Windows taskbar clock cannot display seconds since Windows 95.
Why? Because when installed on a 4 Mb machine, Windows 95 was too slow to display seconds. This and other lame excuses are blogged at MSDN. There is a whole shareware industry around Windows to fix this problem. If you want to measure time, use online javascript stop watch or US atomic clock at time.gov

Java sighting on a cup of milk

Looking at this cup of soy milk in Taipei, I thought at first that somebody stole Java logo. Then, looking closer, I realized it's a genuine ad for Java training. Something you won't see on a milk container in the US...

Form based login from a shell script

The following code uses only shell scripting and curl to log in to a website protected by a form based authentication and download contents of page "about.jspx". We pay special attention to returning reasonable error messages. These snippets were tested with Tomcat 5.5.

1. Get user name, password, and the application's URL from the command line,

   eval set -- $(getopt "u:p:b:" "$@")
   while [ "$1" != "--" ]
   do
       case "$1" in
       -u) shift; WEB_UID="$1"; shift; ;;
       -p) shift; WEB_PWD="$1"; shift; ;;
       -b) shift; BASE_URL="${1%\/}"; shift; ;;
       esac
   done
   

2. Store URLs in variables,
   

   typeset aboutUrl="$BASE_URL/about.jspx"
   typeset securityAction="$BASE_URL/j_security_check"
   typeset logoffUrl="$BASE_URL/logoff.jsp"
   

3. Access the URL and look for session cookie JSESSIONID,
   

   headers="$(curl -s -S -f -L -D - -o /dev/null --url "$aboutUrl" 2>&1)" \
   || error "Error accessing $aboutUrl: $headers"
   if [[ "$headers" =~ 'Set-Cookie: JSESSIONID=([^;]*)' ]]
   then
       sid="${BASH_REMATCH[1]}"
   fi
   

4. If JSESSIONID cookie is set, submit user name and password to the login form. On success, the application will redirect us to the original URL. Variable "about" will store the page source or the error message.
   

   about="$(curl -s -S -L -f -b "JSESSIONID=$sid" -o - \
   -d "j_username=$WEB_UID" \
   -d "j_password=$WEB_PWD" \
   --url "$securityAction" 2>&1)" \
   || error "Error submitting credentials to $securityAction: $about"
   

5. Parse the page for some useful information (looking for <sysdate date="20071102">)
   

   if [[ "$about" =~ 'sysdate date=\"([^\"]*)\"' ]]
   then
       date="${BASH_REMATCH[1]}"
   fi

6. Finally, hit the logoff URL so that the application may clean up.
   

   curl -s -f -b "JSESSIONID=$sid" --url "$logoffUrl" -o /dev/null

For more information, see cURL and libcurl

Sun NetBeans day

September 11th was a Sun NetBeans day in Boston. Here's what I learned:

• NetBeans keeps improving. NetBeans 6 consolidates six independent Java parsers of version 5 into one. Syntax highlighting and refactoring can now use more semantic information; it is now faster and more powerful and accurate.
• Profiler is now improved and built-in into NetBeans. It can be enabled or disabled at runtime using profiling points. More info at Netbeans profiler pages.
  
• The most active site about NetBeans is NetBeans Wiki.
  
• New England has an active Java User Group, which organizes nice talks. See NEJUG.org
• A lot of introductory presentation about Java technology inluding RIA and REST is posted by one of the speakers at JavaPassion.com. The speaker himself was speaking way too fast with a Korean accent, but his presentations must be filled with information.