Category Archives: Computer

Computer related topics

Unable to change label properties of push button/hyperlink in Application Designer

I had the issue where when I opened up the Label tab of a push button on a page, the Label Type, Label Size are blank, Label Text shows up as Static Text. When I changed the settings, and clicked OK to save it. The change did not register.

The fix turned out to be to go to the Configuration Manager, then go to Client Setup tab, then check the “Install Workstation” checkbox, click OK or Apply.

Now restart Application Designer, the issue should be fixed now.

Playing flv file on VLC media player

When I play a flv file on VLC media player, it consumes a lot of CPU. Whenever I try to fast forward, the player just locks up, and I will no longer be able to fast forward or backward.  Even if I close the player, it stays in Task Manager with huge CPU load.


and I will have to kill it from Task Manager.

Since VLC gives me more benefits, I just don’t want to switch. So I go online, one post here says to enable “fast-seek”. When I go in to the preferences of VLC media player:


I don’t see “fast-seek” here. However, I do notice the “Hardware-accelerated decoding” is set to “Disable”. I change it to Automatic,


And try again:


Now it’s all good, it’s running low on CPU, and I can fast-forward or backward.


One issue still here is that I can’t pause it, when I do, the CPU again goes up, and I no longer can close it in the usual way.

Perl Style

A little about Perl style from perldoc.

  1. Run under –w flag all times
  2. Run under “use strict”
  3. Can also use “use sigtrap” or “use diagnostics”
  4. Closing curly bracket of a multi-line block should line up with the keyword that started the construct
  5. 4-column indent
  6. Open curly on same line as keywork, if possible, otherwise line up.
  7. Space before the opening curly of a multi-line block.
  8. One-line BLOCK may be put on one line, including curlies.
  9. No space before the semicolon.
  10. Semicolon omitted in “short” one-line BLOCK.
  11. Space around most operators.
  12. Space around a “complex” subscript (inside brackets).
  13. Blank lines between chunks that do different things.
  14. Uncuddled elses.
  15. No space between function name and its opening parenthesis.
  16. Space after each comma.
  17. Long lines broken after an operator (except “and” and “or”).
  18. Space after last parenthesis matching on current line.
  19. Line up corresponding items vertically.
  20. Omit redundant punctuation as long as clarity doesn’t suffer.
  21. When in double, parenthesize

Perl Misc

$. Line number
$_ Input line
$” This is similar to $,, except it applies to array values interpolated into a double quoted string.
$, Field separator
$\ Output Record Separator
$/ Input Record Separator

-F Input field separator
-E Just like -e, plus enabling Perl 5.10 features
-i Inline edit
-p Print each line right away
-l Add new line
-a Split input line into @F
-00 Turns paragraph slurp mode on.

-0777 Together with –n causes Perl to slurp the whole file into $_.
perl -00pe0 # here code is 0, which does nothing

@{[reverse @F]}


\012, \015

%-5d Alignes to left.


perl -e “print map { (a..z)[rand 26] } 1..8″

   # your program goes here
} continue {
   print or die “-p failed: $!\n”;

somecode unless /^$/
somecode if /reg/

$n = () = <>
$n = ( () = <> )
scalar( () = <> )

perl -e “}{ print $.”
   # this is like:
   while (<>) {
   }{ # eskimo operator here
      print $.;
perl –alne ‘map { /regex/ && $t++ } @F; END {print $t || 0 }’


print if 1..10   print first 10 lines

print if eof  prints last line.

scalar(grep { /./ } <> )

$x+0: this can be useful if $x is not initialized.

perl -ne “/regex/ && $last && print $last; $last = $_”
   print every line preceding a line that matches a RE.
perl -ne “$. == 13 && print && exit”

perl -ne “print && $. != 27″

perl -ne “print if $. == 13 || $. == 19″

flip-flop operator/range operator
perl -ne “print if /regex1/../regex2/”
   print all lines between two REs

perl -ne “print if ++$a{$_} == 2″
   print all repeated lines only once

perl -ne “print unless $a{$_}++”
   print unique lines

“Your license code does not permit access”


Go to SQL Developer, and query PSOPTIONS table:


Hmm, I found the code there seems to be correct.

I think I have to do a trace to find out what table it’s reading.

Hmm, it is reading PSOPTIONS.

I went ahead and updated it anyway.

Well, that did not work. Still some components are having the same error.

Suddenly I realized that I was looking at key for this:


There is another set of keys:


Update the table PSOPTIONS with this key, and bingo, it worked.