Tag Archives: Programming

Perl Redirect Command Output

In Perl, you can execute external commands using system() or ``. However, system and `` does not redirect command output to console and this results people who runs your perl script can't see it. This also make debug much harder. Perl does not have a build in switch that equals to batch scripts’ "@echo on", however this can be worked around by creating a ExecuteCommand subroutine.

sub ExecuteCommand {
my $cmd= $_;
my @cmdoutput = `$cmd`;
for $line (@cmdoutput) {
print $line;

Now just change your code from system($command) or `$command` to ExecuteCommand($command) and you will see all command output are redirected to console. Continue reading

How to Validate URL in C#

I searched google for how to validate URL in C# and most results say using a regular expression. Eventually I found Uri.TryCreate which is a built in method in C# to check if a string is a valid URL

Uri uri = null;

if (!Uri.TryCreate(url, UriKind.Absolute, out uri) || null == uri)


    //Invalid URL

    return false;





SpellChecker in WPF4 TextBox

TextBox and RichTextBox in WPF4 has the built in SpellChecker functionality. It’s currently available in following four languages

  • #LID 1033 – English
  • #LID 3082 – Spanish
  • #LID 1031 – German
  • #LID 1036 – French

Enable SpellChecker functionality on TextBox or RichTextBox is as easy as just setting SpellCheck.IsEnabled to True on the controls.

   <TextBox SpellCheck.IsEnabled="True" />

Continue reading