Cow Computing » Bug

WordPress Error: Cannot Modify Header Information

Steve — Mon, 08 Mar 2010 02:14:06 +0000

Have you ever encountered the error: “Cannot modify header information” when you try to access the admin page of wordpress? The debug message might have suggested you to look at “pluggable.php”. When searching thru google, people often advise you to turn off installed-plugin one by one to see if the problem get resolved.

The above might work, but i would suggest you to try the following method before going thru the turn-off plugin cycle. For example, if you have modified “functions.php”, and the above header information header appeared right after, you can easily resolve this by removing all the extra whitespace before the “” tag. Viewing thru editor, you might not notice any whitespace, but try this trick:

Remove the “>” from the “?>” tag at the end of file
Then keep holding Delete key (not backspace) for a few seconds. (*note that the cursor should be locate after the “?”)
You will notice some whitespace being deleted. Amazing isn’t it?
Add the “>” after the “?” to properly close the php tag
Save the file, and try accessing it, the header information error should have been resolved

Solution: Eclipse Mouse Click Problem in Ubuntu 9.10

Steve — Tue, 15 Dec 2009 06:49:05 +0000

Recently, i have my Ubuntu VM upgraded from 9.04 to 9.10 aka Karmic. And when i tried to develop program using eclipse, i found out that, sometimes, in certain dialog boxes, “next” or “ok” button didn’t give any response. Initially, i thought it’s my VM’s problem, but when i repeated it with my desktop, the same thing happened. After googling abit, it was found that the problem was due the the recent change in GTK with 9.10.

To get around the problem, the simplest thing to do is to “Tab” and “Enter”. It was so annoying…

Luckily, there’s a trouble-free solution to it. You might try to set the environmental variable “GDK_NATIVE_WINDOWS” to true before executing the eclipse. To make thing simpler, here’s a eclipse.sh that you might want to use for starting eclipse.

#eclipse.sh
#!/bin/sh
export GDK_NATIVE_WINDOWS=true
/eclipse

Do change the to your eclipse’s current location. chmod it to 777 and run it with ./eclipse.sh

JAVA Substring Bug!

Steve — Sun, 06 Sep 2009 09:53:41 +0000

Sometimes, when we are working with string in java, we are always tempted to use the substring method for extracting part of a string. It’s neat and efficient when you are working with small program or little string processing. However, this method is evil. It is actually causing you whole lots of problem. The substring returns the part of the original string rather than a new one. Thus, GC wont collect the original string. So when the file or string get larger and larger, it’s actually taking up more and more memory, and thus OutOfMemory Error. To solve this, there’s nice workaround which is simple.

String newString = new String( oldString.subString(0, 5) );

Simple, Right?!