[Tutor] Scrolling through output in shell

[Lie Ryan]

On Mon, 17 Nov 2008 09:20:55 -0500, Shawn Milochik wrote:

> On Sun, Nov 16, 2008 at 1:21 PM, Mike Hoy <mhoy06 at gmail.com> wrote:
>> I'm writing a small program that writes to a text file. I want to be
>> able to view the contents of the text file inside of shell. But the
>> file is too large for a small shell window. Is there a way for the user
>> to 'scroll' through the contents of file that has been read into the
>> program? I noticed that on the man pages that you can do that although
>> I'm sure it's not written in python. Do I need to find a new language
>> to write this in? Maybe use a different language for the output and
>> still use python? Any help appreciated.
>>
>> --
>> Mike Hoy
>> http://www.mikehoy.net
> 
> 
> 
> As Alan has noted, your request isn't perfectly clear. So, I'm going to
> change your question and answer it. If I picked the wrong question,
> please be more explicit in your next reply.
> 
> Question: How can I read a text file from the command line if the file
> is too large to fit on the screen at once?
> 
> Answer: more or less
> If you're in Windows, you can use the more command: more file.txt That
> will allow you to scroll up and down.
> 
> If you're on pretty much any other OS, you can use more or less. I
> prefer less, because it has more features. You use it the same way you
> use more:  less file.txt

If that explanations mixing up "more" and "less" as names of programs and 
more and less for real more and less doesn't confuse you, I think you 
must already know what "more" and "less" is.

"more" and "less" is a pager program, used to provide scroll facility to 
a file or a stream. Windows only have "more", many Unix-like OS provide 
both "more" and "less". The most striking difference between "more" and 
"less" is that "more" is simple forward-only, you can't scroll up, only 
down. "less" support both backward and forward navigation.

As the manpage of "less" explains: 'less - opposite of more'