CODEWITHSUNDEEP
bashshellawk
wookie1
wookie1

Reputation: 511

Awk to nearest match

Hi I'm trying to take the column 9 results corresponding to the first point in column 2 that starts with 4.4. Here's what I have so far.

echo $(awk "$2 ~ /4.4*/ {print $9}" 'myfile') >>"myoutputfile"

Unfortunately this is syntactically incorrect but I can't see how to fix it. Any help would be much appreciated. Thanks.

Upvotes: 0

Views: 119

Answers (3)

Chris Seymour
Chris Seymour

Reputation: 85785

The correct syntax is:

awk '$2~/^4\.4/{print $9}' myfile >> myoutputfile

This will append the ninth field in myfile to myoutputfile if the second fields matches the regex ^4\.4. The regexp matches if the second field starts with ^ a 4 followed by a period . followed by a 4.

Notes:

  • >> is the append operator if you only want myoutputfile to contain the output from the awk command the use the redirection operator > this will empty the file first.

  • awk prints to stdout by default, using backticks and echo isn't required.

  • awk script should be inclosed in single quotes only and the files do not need quoted here.

EDIT:

To only return the first match using exit to quit the script:

awk '$2~/^4\.4/{print $9;exit}' myfile

Upvotes: 5

Kent
Kent

Reputation: 195039

starts with 4.4

should be /^4\.4.*/

so:

awk '$2~/^4\.4.*/{print $9}' myfile >> myoutputfile

some example/explanation:

4.4* matches foo4x4, foo4x4444 ...
^4\.4* matches 4.4, 4.44444, also 4.   ... but not 4.45850
^4\.4.* (same as ^4\.4) matches 4.4, 4.4444, 4.45567 and 4.4abcde

If you only want to have numbers following 4.4, use:

/^4\.4[0-9]*$/

Upvotes: 1

oHo
oHo

Reputation: 54551

awk '$2 ~ /^4[.]4/ {print $9}' myfile >> myoutputfile

symbol ^ means the beginning of the column.

Upvotes: 2

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