command for grep the exact word

nagendrar · 04-28-2009, 11:33 PM

I have two lines in a file like below

Host *
Host-specific *

Here I want to grep the "Host *" line only.

I had tried following way but I did not get exact line

grep -w Host filename

Please give the suggestions for grep exact line using specific word.

Thanks,
Nagendra.

syg00 · 04-29-2009, 12:01 AM

You already have it - it is simply that you have the wrong understanding of what a "word" is.
Have a look at the manpage again.

Simplest for what you want might be to use character classes - [[:space:]] say - before and after the "word" you want. May lead to other surprises of course ...

chrism01 · 04-29-2009, 01:38 AM

a simple soln:

Code:

grep 'Host ' filename

nagendrar · 04-29-2009, 02:06 AM

If there is tab space between Host and * then we did not get output using

grep 'Host ' filename.

Thanks,
Nagendra

flopypl · 04-29-2009, 02:10 AM

yesterday's thread: http://www.linuxquestions.org/questi...-linux-721931/

mayby that will help you something.

colucix · 04-29-2009, 03:12 AM

Quote:

Originally Posted by nagendrar

If there is tab space between Host and * then we did not get output using

grep 'Host ' filename.

Code:

grep Host[[:space:]] filename

the [:space:] class includes space, TAB, formfeed and so on.

knudfl · 04-29-2009, 02:16 PM

How about

cat <file> | grep "\Host\ "

H_TeXMeX_H · 04-29-2009, 02:33 PM

You may also want to try 'grep -x'

Code:

       -x, --line-regexp
              Select only those matches that exactly match the whole line.

Not sure if that's what you want to do tho.