util.rb

# Common utilities.

require 'shellwords'

PWD = ENV['PWD'] || ::Dir.pwd

def path_with_tilde(abs_path)
  home = ENV['HOME']
  # Only abbreviate the home dir when it is a leading path component: anchored to the
  # start and followed by a separator (or the end), with regex metacharacters escaped.
  abs_path.sub(/\A#{Regexp.escape(home)}(?=\/|\z)/, '~')
end

def pipe_to_fzf_and_print(fzf_input, reverse, env_var)
  # Ignore --fzf command (must be first arg).
  query = ARGV[1..-1].join(' ')
  # The opts env vars contain shell-quoted option strings; split them like a shell would.
  opts = Shellwords.split(ENV['COMPNAV_FZF_OPTS'] || '') +
         Shellwords.split(ENV[env_var] || '')
  opts.unshift '--tac' if reverse

  # Invoke fzf directly (no shell) so that directory names and the query are passed as data,
  # never interpreted as code. fzf reads the list from stdin and still draws its UI on /dev/tty.
  # --query: Start fzf with any given arguments as the query.
  IO.popen(['fzf', '--query', query, *opts], 'r+') do |fzf|
    fzf.write fzf_input
    fzf.close_write
    puts fzf.read
  end
end