grep exact pattern 3

[jdhahbi]

Hi
I am using grep to extract a certain pattern in the example files below. How do I extract pattern 'T1' and not 'T123'?

cat pattern
id
T1
T23
T55

cat file
id	name	length
T5	Lypla1	2433
T55	sea3	2668
T123	Tmea1	2671
T23	nrea1	2564
T1	mea1	250
T10	mrty1	22

grep -f pattern file
id	name	length
T55	sea3	2668
T123	Tmea1	2671
T23	nrea1	2564
T1	mea1	250
T10	mrty1	22

the output should be:

id	name	length
T1	mea1	250
T23	nrea1	2564
T55	sea3	2668

Thank you for your help
Joseph

 

[feherke]

Hi

Your question is off-topic. Please ask [tt]grep[/tt] related questions in forum822 or forum619 or whatever is appropriate.

Regarding your question with GNU [tt]grep[/tt] you can use the [tt]-w[/tt] ( [tt]--word-regexp[/tt] ) switch to anchor the patterns to word boundaries :

grep [red]-w[/red] -f pattern file

Feherke.

http://feherke.github.com/

 

[PHV]

And as you asked in the awk forum:

awk 'NR==FNR{++p[$1];next}($1 in p)' pattern file

Hope This Helps, PH.
FAQ219-2884
FAQ181-2886

 

[FlorianAwk]

Or adapt your regular expression to what you really want:

cat pattern
id
T1[^[:digit:]]
T23
T55