shell script

[Jonathan Billings]

On Tue, Jul 17, 2007 at 07:19:36PM +0530, Mahalingam Subramaniam wrote:
>    Dear All
> 
>    My Query is as follows:
> 
>    I have extracted the output and details of mail users mail inbox size with
>    file path name.
> 
>    140K /abcde/fghij/w001/wesley
>    26M /mnopq/rstuvwx/w001/wilson
>    1G /mnopq/rstuvwx/w001/alok
>    2G /mnopq/rstuvwx/w001/john
> 
>    Here, I want to extract and paste the output of only users whose inbox
>    size is 1GB or more than 1GB using shell script "cat"
>    (e.g.) cat mailstorage.txt (source file containing all users mail inbox
>    size information) |awk -F ' ' '{print...... >> gboutput.txt (target file
>    to paste the final output) similar to this.

I'd probably use perl, since it can save you some effort

perl -nale 'print((split("/",$F[1]))[-1]) if $F[0]=~/^\d+G/' mailstorage.txt 

(If you'd like me to explain what I'm doing, let me know. I realize
some people think perl resembles line noise.)

Also, I'd like to note, typing 'cat file.txt | awk ...' or 'cat
file.txt | grep ...' generates a useless pipe.  Just pass the file as
an argument to awk or grep, they can handle the file I/O.  This can
save a lot of memory and time if you are working with very large
files. 

-- 
Jonathan Billings <jsbillin at princeton.edu>
Computational Science and Engineering Support (CSES)
http://www.princeton.edu/~cses/