Function to extract columns from an input stream

 $ col() { awk '{print $('$(echo $* | sed -e s/-/NF-/g -e 's/ /),$(/g')')}'; }

— by Janos on Dec. 7, 2012, 4:14 p.m.


A slightly improved version of the original one-liner to allow negative indexes to extract columns relative to the end of the line, for example:

$ echo a b c | col 1 -0 -1
a c b

In this example the function expands to:

awk '{print $(1), $(NF-0), $(NF-1)}'