Thank you all for your replies.
I am using Ubuntu and Emacs GTK+ Version 2.12.9. Nothing else is used by me.
My tool is just a Haskell program, and I load it using GHCi to run. 

Is the emacs that limits the length of the command then?

Best regards,

Kwanghoon

On Sun, Feb 28, 2010 at 4:54 PM, Kwanghoon Choi <lazyswamp@gmail.com> wrote:
 
Dear Haskeller,
 
I have a little issue in using GHCi as follows:
 
===
Prelude> length "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
<interactive>:1:254:
    lexical error in string/character literal at character '\EOT'
===
 
It seems to me that GHCi doesn't allow me to type more than some specified length of a command.
Is this interpretation correct? How can I make it longer?
 
This issue is quite important at least to me. My tool is just a simple Haskell program. I don't like to add any extra interactive environment, but I like to just use GHCi as an interactive environment for my tool. I strongly believe that this ides is pervasive among many haskellers.
 
Thanks in advance for your help/feedback in advance.
 
Kwanghoon