UNIX for Advanced & Expert Users

With awk:

Code:

awk '{print; if ($1=="LAC") exit}' file

Code:

awk '{print; if ($2=="LAC") exit}' file

Code:

awk '{print; if ($1=="LAC" || $2=="LAC") exit}' file

But there is one catch in the case of sed. If the match is on the first line, then it will not work.. To handle this case you need a GNU extension (GNU sed):

Code:

gsed -n '0,/\<LAC\>/p' file

awk does not have this problem and can also use a range expression and also can have an exact field match as noted by MadeInGermany, so you do not need to delimit the search:

Code:

awk 'NR==1, $1=="LAC"||$2=="LAC"' file

or

Code:

awk -v s=LAC 'NR==1, $1==s||$2==s' file

MadeinGermany's approach with the exit statement would be more efficient.

--
This exit approach would also work with regular sed and this does not have the match-on-line-1 catch:

Code:

sed '/^LAC$/q; /^LAC[[:blank:]]/q; /[[:blank:]]LAC[[:blank:]]/q' file