21–30 of 79 posts
I have no idea what this is doing, but it sure looks interesting.
It's using Ruby to replace Awk, the way Perl once tried to.
Interesting, so it's reading text from STDIN into an Array, then executing its arguments as Ruby code in the context of that Array (or if you pass -l, in the context of each line individually). So all the standard methods on the [Array][1] (or [String][2]) class become accessible as top-level methods. A few examples: Capitalizing a line: echo hello world | rb -l capitalize Printing only unique lines: printf 'hello\nw…
echo hello world | ruby -pe '$_.capitalize!' printf 'hello\nworld\nhello\n' | ruby -le 'puts STDIN.to_a.uniq ps | ruby -lane 'BEGIN { b = 0 }; b += $F[0].to_i; END { print "sum of PIDs: #{b}" } select whatever column you want, to sum up. Really what Ruby needs is a flag that adds some capabilities to NilClass, so that these BEGIN blocks aren't needed.
Does it, though?
ps | ruby -le 'b = $ ps | ruby -lane 'b = (b || 0) + $F[0].to_i; END { print "sum of PIDs: #{b}" }' $ docker ps | rb drop 1 | rb -l split[1]
$ docker ps | perl -anE 'say $F[1] if $.>1'
Command line tools in 10 lines of ruby (using this script): docker ps | rb drop 1 | rb -l split[1] docker ps -a | rb grep /Exited/ | rb -l 'split.last.ljust(20) + " => " + split(/ {2,}/)[-2]' df -h | rb 'drop(1).sort_by { |l| l.split[-2].to_f }' Command line tools in zero lines of ruby (using ruby): docker ps | ruby -lane 'next if $. == 1; print $F[1] docker ps -a | ruby -lne 'print $1 if /(Exited .*? ago)/' df | rub…
df -h | ruby -e 'puts readlines.drop(1).sort_by { |l| l.split[-2].to_f }'
printf 'hello\nworld\nhello\n' | ruby -e 'puts readlines.uniq'$ docker ps | rb drop 1 | rb -l split[1] $ docker ps | perl -anE 'say $F[1] if $.>1' perl solved this problem a long time ago, people
awk 'NR>1{print $2}'
ruby -ane 'puts $F[1] if $.>1'
Further reading(disclosure: I wrote these)
[0]: https://github.com/learnbyexample/Command-line-text-processi...
[1]: https://github.com/learnbyexample/Command-line-text-processi...
[2]: https://github.com/learnbyexample/Command-line-text-processi...
I though it was great, knowing python better than bash, plus it was portable to windows.
But eventually I always end up using built in GNU tools.
Don't know why. It just rolls better.
Earlier quoted context omitted.
Out of interest, why are you not a fan of Ruby?
Right tool for the job; don't be a fan boy.
$ docker ps | rb drop 1 | rb -l split[1] $ docker ps | perl -anE 'say $F[1] if $.>1' perl solved this problem a long time ago, people