Awk - select from a list

simha77777 · #1 (**permalink**) 02-05-2008

Hi all,

I am trying to select some columns from a file, based on the list of values.
Would like to know how best I can achive this.

If coulmn 1 has a value of 57 then print the ist column (This works)

Code:

awk -F'  ' '{if ( $1 == 57 ) {print $1}}' file.txt

Now my requirement is that I have to check the column with multiple values. (If I have 2 use an OR operator as below)

Code:

awk -F'  ' '{if ( $1 == 57 || $1 == 58) {print $1}}' file.txt

I have 100 values which I need to check with the first column. Is there a way to do this, without writing in 100 conditions in the if statement?
(I could put the 100 values into a file if that makes things easier)

Please let me know if you need more information. Any help greatly appreciated.

Yogesh Sawant · #2 (**permalink**) 02-06-2008

how about putting a regex instead of those hundred comparisons?

simha77777 · #3 (**permalink**) 02-06-2008

Thank you for the response.

In my case, I don't have a definite pattern to use as a regexp, I would have to pass a list of numbers, which might not be in a sequence.
HTH

vgersh99 · #4 (**permalink**) 02-06-2008

assuming numberList is a file containing 'numbers' to be filtered - one number per line.
And 'myFile' is a file to check the numbers against.

nawk -f simha.awk numberList myFile

simha.awk:

Code:

NR==FNR { numList[$1]; next}
$1 in numList {print $1}

simha77777 · #5 (**permalink**) 02-06-2008

vgersh99,

Pardon my ignorance -
Just a little clarification needed here.
numList and numberList mismatch is a typo or it needs to be that way?

Also how do I check for a particular coulmn in the myFile (for example the 14th coulmn). The delimiter is tab in myFile.

Thanks for your time.

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