commandline map

map.rb

#!/usr/bin/env ruby

# like map(), except on shell pipelines

# one arg: the mapper
# transform input lines, via the mapper, into output lines
# mapper is eval'd within the input line string
#  
# extract 2nd column
#   cat file | map 'split[1]'
# normalize url's
#   cat kinda-urls | map 'if self !~ %r[^http://] then "http://#{self}" else self; end'

# designed for dotfiles.org/~brendano/.irbrc
if File.exists?("#{ENV['HOME']}/.irbrc")
  $irbrc_extensions_only = true
  load "~/.irbrc"
end

cmd = ARGV.join(" ")
STDIN.each do |line|
  puts line.chomp.instance_eval { eval cmd }
end