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Comment by penguin_booze | Hacker News Reader

I'd like to give a shoutout to jq for (non-JSON) text processing, and also as an almost-replacement for awk:

  echo "foo bar" | jq -Rr 'split(" ")[0]' # prints foo

I say 'almost', because jq right now can't invoke sub processes from within, unlike awk and bash. But otherwise, it's a fully fledged, functional, language.

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Same! and jq's regexp functions are quite powerful for transforming text into something more structured:

  $ echo -e "10:20: hello\n20:39: world" | jq -cR 'capture("^(?<timestamp>.*): (?<message>.*)$")'
  {"timestamp":"10:20","message":"hello"}
  {"timestamp":"20:39","message":"world"}


  $ echo -e "10:20: hello\n20:39: world" | jq -Rn '[inputs | capture("(?<t>.*): (?<m>.*)$").m] | join(" ")'
  "hello world"

Also using inputs/0 etc in combination with reduce and foreach it's possible to process streams of text that might not end.

`jq -Rr 'split(" ")[0]'`? That would easily take me three decades to memorize ;-).

for selecting the second column, PID, from `ps aux`,

    ps aux | awk '{print $2}'

works for me, as gawk's default $FS field separator treats runs of whitespaces as a single separation of fields ( https://www.gnu.org/software/gawk/manual/html_node/Field-Spl... ), quite similar to "standard" Open Group/POSIX awk ( https://pubs.opengroup.org/onlinepubs/9799919799/utilities/a... ).

    ps aux | jq -Rr 'split(" ")[1]'

on the other hand doesn't work here due to `ps aux` adding a variable number of spaces for formatting.

    ps aux | jq -Rr 'split("\\s+"; null)[1]'

seems to work though.

Yes, in awk, conveniently, whitespace means a run of whitespace. It gets a bit verbose in jq for the same effect; but on the other hand, you get slicing - more slices than `cut` can give you.

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