using 'more' instead of 'cat' to pipe into another command
Hi, quick question. Since i am in the habit of using 'more' to view files, e.g.
Code:
$ more my_file.txt
I often use this command to pipe into other utilities like grep. For example,
Code:
$ more my_file.txt | grep '^>'
would get all lines in the file that begin with ">". I know that it is generally recommended to use 'cat' for this purpose, so I was wondering if there is a speed difference between the two commands? In other words, would it be faster to say:
Code:
$ cat my_file.txt | grep '^>'
? Since i routinely work with very large text files, the speed difference could be important.
(Note: I realize that 'grep' takes a file argument like this:
Code:
$ grep '^>' my_file.txt
but i am only using it as an example. It can be anything. I am more interested in the 'cat' vs. 'more' difference.)
Thanks!
Last edited by pludi; 07-01-2010 at 10:48 PM..
Reason: code tags, please...
There is a format difference between "more" and "cat". The "more" process includes screen formatting characters. Don't ever feed the output from "more" into a pipe for further processing, use "cat" or shell inward redirect.
Yes, that's what I meant. "more" is only meaningful when its output is the user's tty. When it is piped to a process, all the internal interaction logic is disabled.
also... when in "more", you can press "v" and the content will be loaded into "vi", it is very convenient, I learned it from unixacademy.com "Learn Linux For A Beginner" training
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