Grep question

[Sachin_29]

I am trying to grep for a word ABC in a line withn a file
The file test contains
The word is ABC
Something ABC.orig
when i do grep ABC test|wc -l . It returns 2
Is there any way i could grep for the exact word ABC?

[Carlo Corthouts]

If ABC.orig is also in that file you can try :

grep ABC test|grep -v ABC.orig | wc -l

[Sachin_29]

sorry i meant there could be more words where like ABC.dontknow ABC234 etc

[Pete Randall]

Try

grep " ABC " test


Pete

[RAC_1]

grep -x [A]BC file

Else get GNU grep.


Anil

[Sachin_29]

doesnt help pete!!!

[Franky_1]

Hi,

just

grep " ABC" test

Regards

Franky

[Carlo Corthouts]

Try grep -w ABC

[Simon Hargrave]

You'll need anchors: -

If you want to grep for ABC as part of a line: -

grep " ABC " file (note the spaces)

If you want a line with ONLY ABC: -

grep "^ABC$" file (^ anchors start of line, $ anchors end)

[Simon Hargrave]

If you want to anchor to spaces AND tabs (which may be valid depending on your file), then: -

grep "[ | ]ABC[ | ]" file

Where the brackets contain "space pipe tab"

[Rick Garland]

`grep -x` will do an EXACT match.

[John Palmer]

How about:

grep -e " ABC " -e " ABC$" -e "^ABC " -e "^ABC$"

That will find:
1. ABC surrounded by spaces.
2. ABC ending a line
3. ABC starting a line
4. A line consisting only of ABC

Regards,
John

[Carlo Corthouts]

Or you can do

#man grep

[Sachin_29]

John I am getting Illegal Variable name?

[Pete Randall]

The best solution then is the grep -x syntax.
$ grep -x ABC test
ABC
$


Pete

[Sachin_29]

Pete:
the grep -x ABC doesnt work as it looks for the exact line ..the lines are "The word is ABC" and "Something ABC.orig" so if i do grep -x ABC test|wc -l it returns 0

[Rick Garland]

The grep -x does not look for exact lines, it looks for exact patterns.

If you have ABC on a line then grep -x ABC will match. If ABC has multiple and different patterns then the grep -x will not match.

[RAC_1]

grep -w [A]BC

Else get GNU grep

Anil

[Sachin_29]

hey
grep ABC$ test works

[Bill Hassell]

The problem is in the different possibilities of a "word". Typically, a word is defined as text surrounded by whitespace. ABC on a line all by iteself is followed by the whitespace character NEWLINE. In your working example ABC$, grep is looking for ABC at the exact end of the line. ABC$ will not find ABC followed by a space or any other character. The -w option is only for current patches for grep but should work for your requirement.

[Bill Hassell]

The problem is in the definition of a "word". Typically, a word is defined as text surrounded by whitespace. ABC on a line all by itself is followed by the whitespace character NEWLINE. In your working example ABC$, grep is looking for ABC at the exact end of the line. ABC$ will not find ABC followed by a space or any other character. The -w option is only for current patches for grep but per the man page, -w defines a 'word' as a string surrounded by anything that is not alphanumeric or and underscore. Thus, ABC.orig has 2 words ABC and orig with a non-word constituent character in between.

[Suresh Pai]

A slight variation of John Palmer's solution is to ensure that ABC is surrounded by whitespaces..(else his solution just boils down to a grep ABC).

Something like:
grep "[ \t]ABC[ \t]\|[ \t]ABC$\|^ABC[ \t]\|^ABC$" test |wc -l

However, both our solutions do not give you an accurate count of no of ABCs (if more than one is present on the same line).

[Rick Garland]

A good point.
The `wc -l` does not provide a count of the number of instances of ABC, just the number of lines it is found on.

So if it present 5 times on 1 line, the return from the `wc -l` will be 1. This pattern was only found on 1 line.

[Hein van den Heuvel]

Please consider using 'advance search' (aka 'more options') to look for prior discussion before entering.
Search for 'grep word' gives numerous useful prior topics.

perl's \b is great for this wrok as per:

http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=228233


A couple of months ago I suggested:

grep -E '(^|[ \t])searchstring([ \t]|$)' file

In English:

Look for a piece of searchstring starting at (the being of a line or with (space or tab)) and ending with ((space or tab) or the end of a line)

That was in topic:
http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=284829


hth,
Hein.