Question

I’m learning awk from The AWK Programming Language and I have a problem with one of the examples.

If I wanted to print $3 if $2 is equal to a value (e.g.1), I was using this command which works fine:

awk '$2==1 {print $3}' <infile> | more

But when I substitute 1 by another searching criteria, (e.g.findtext), the command doesn’t work:

awk '$1== findtext {print $3}' <infile> | more

It returns no output and I’m sure that ‘findtext’ exist on the input file.

I also tried this, but it does not work:

awk '$1== "findtext" {print $3}' <infile> | more

Here’s my test file named ‘test’ and it has 9 lines and 8 fields, separated by space:

1 11 0.959660297 0 0.021231423 -0.0073 -0.0031 MhZisp
2 14 0.180467091 0.800424628 0 0.0566 0.0103 ClNonZ
3 19 0.98089172 0 0 -0.0158 0.0124 MhNonZ
4 15 0.704883227 0.265392781 0.010615711 -0.0087 -0.0092 MhZisp
5 22 0.010615711 0.959660297 0.010615711 0.0476 0.0061 ClNonZ
6 23 0.715498938 0 0.265392781 -0.0013 -0.0309 Unkn
7 26 0.927813163 0 0.053078556 -0.0051 -0.0636 MhZisp
8 44 0.55626327 0.222929936 0.201698514 0.0053 -0.0438 MhZisp
9 31 0.492569002 0.350318471 0.138004246 0.0485 0.0088 ClNonZ

Here’s what I did and the output:

$awk '$8 == "ClNonZ" {print $3}' test 

$ grep ClNonZ test 
2 14 0.180467091 0.800424628 0 0.0566 0.0103 ClNonZ
5 22 0.010615711 0.959660297 0.010615711 0.0476 0.0061 ClNonZ
9 31 0.492569002 0.350318471 0.138004246 0.0485 0.0088 ClNonZ

I expect to see this which is the $3 that has “ClNonZ” in their $8.

0.180467091 
0.010615711 
0.492569002

Don’t know why the awk command didn’t return anything. Any thoughts?

Answer 1

If you’re looking for a particular string, put quotes around it:

awk '$1 == "findtext" {print $3}'

Otherwise, awk will assume it’s a variable name.