A simple function to conveniently extract columns from an input stream

col() { awk '{print $('$(echo $* | sed -e s/-/NF-/g -e 's/ /),$(/g')')}'; }
Something I do a lot is extract columns from some input where cut is not suitable because the columns are separated by not a single character but multiple spaces or tabs. So I often do things like: ... | awk '{print $7, $8}' ... which is a lot of typing, additionally slowed down when typing symbols like '{}$ ... Using the simple one-line function above makes it easier and faster: ... | col 7 8 How it works: The one-liner defines a new function with name col The function will execute awk, and it expects standard input (coming from a pipe or input redirection) The function arguments are processed with sed to use them with awk: replace all spaces with ,$ so that for example 1 2 3 becomes 1,$2,$3, which is inserted into the awk command to become the well formatted shell command: awk '{print $1,$2,$3}' Allows negative indexes to extract columns relative to the end of the line. Credit: http://www.bashoneliners.com/oneliners/oneliner/144/
Sample Output
$ echo a b c | col 1 -0 -1
a c b

0
By: tekniq
2014-06-05 18:01:31

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