Module: MslinnUtil

Defined in:
lib/util.rb

Class Method Summary collapse

Class Method Details

.common_prefix(paths, allow_root_match: false) ⇒ String

Returns the longest path prefix that is a prefix of all paths in array. If array is empty, return ”. If only the leading slash matches, and allow_root_match is true, return ‘/’, else return ”.

Parameters:

  • paths (Array[String]) —

    all start with a leading ‘/’ (they are assumed to be absolute paths).

Returns:

  • (String) —

    the longest path prefix that is a prefix of all paths in array. If array is empty, return ”. If only the leading slash matches, and allow_root_match is true, return ‘/’, else return ”.



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# File 'lib/util.rb', line 6

def self.common_prefix(paths, allow_root_match: false)
  return '' if paths.empty?

  relative_paths = paths.reject { |x| x.start_with? '/' }
  abort "Error: common_prefix received relative paths:" + relative_paths.map { |x| "  #{x}\n" } \
    unless relative_paths.empty?

  if paths.length == 1
    result = paths.first.split('/').slice(0...-1).join('/')
    return result.empty? && allow_root_match ? '/' : result
  end

  arr = paths.sort
  first = arr.first.split('/')
  last = arr.last.split('/')
  i = 0
  i += 1 while first[i] == last[i] && i <= first.length
  result = first.slice(0, i).join('/')

  result.empty? && allow_root_match ? '/' : result
end

.deref_symlink(symlink) ⇒ Object

Returns Path to symlink.

Returns:

  • Path to symlink



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# File 'lib/util.rb', line 65

def self.deref_symlink(symlink)
  require 'pathname'
  Pathname.new(symlink).realpath
end

.ensure_ends_with(string, suffix) ⇒ Object 



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# File 'lib/util.rb', line 70

def self.ensure_ends_with(string, suffix)
  string = string.delete_suffix suffix
  "#{string}#{suffix}"
end

.expand_env(str) ⇒ Object 



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# File 'lib/util.rb', line 75

def self.expand_env(str)
  str.gsub(/\$([a-zA-Z_][a-zA-Z0-9_]*)|\${\g<1>}|%\g<1>%/) do
    ENV.fetch(Regexp.last_match(1), nil)
  end
end

.roots(paths, level, allow_root_match: false) ⇒ Object

Parameters:

  • paths (Array[String]) —

    absolute paths to examine

  • level (Int) —

    minimum # of leading directory names in result, origin 1



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# File 'lib/util.rb', line 30

def self.roots(paths, level, allow_root_match: false)
  abort "Error: level must be positive, but it is #{level}." unless level.positive?
  return allow_root_match ? '/' : '' if paths.empty?

  abort("Error: level parameter must be positive, #{level} was supplied instead.") if level <= 0

  if paths.length == 1
    root = File.dirname(paths.first)
    return allow_root_match ? '/' : '' if root == '/'

    return root
  end

  loop do
    paths = trim_to_level(paths, level) # does this change paths in the caller?
    return paths.first if paths.length == 1

    level -= 1
    break if level.zero?
  end

  allow_root_match ? '/' : ''
end

.trim_to_level(paths, level) ⇒ Object

Parameters:

  • paths (Array[String]) —

    absolute paths to examine

  • level —

    is origin 1



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# File 'lib/util.rb', line 56

def self.trim_to_level(paths, level)
  result = paths.map do |x|
    elements = x.split('/').reject(&:empty?)
    '/' + elements[0..level - 1].join('/')
  end
  result.sort.uniq
end