class PathExpander

PathExpander helps pre-process command-line arguments expanding directories into their constituent files. It further helps by providing additional mechanisms to make specifying subsets easier with path subtraction and allowing for command-line arguments to be saved in a file.

NOTE: this is NOT an options processor. It is a path processor (basically everything else besides options). It does provide a mechanism for pre-filtering cmdline options, but not with the intent of actually processing them in PathExpander. Use OptionParser to deal with options either before or after passing ARGV through PathExpander.

Attributes

args[RW]

The args array to process.

glob[RW]

The glob used to expand dirs to files.

path[RW]

The path to scan if no paths are found in the initial scan.

Public Class Methods

new(args, glob, path = ".") click to toggle source

Create a new path expander that operates on args and expands via glob as necessary. Takes an optional path arg to fall back on if no paths are found on the initial scan (see process_args).

# File lib/path_expander.rb, line 38
def initialize args, glob, path = "."
  self.args = args
  self.glob = glob
  self.path = path
end

Public Instance Methods

expand_dirs_to_files(*dirs) click to toggle source

Takes an array of paths and returns an array of paths where all directories are expanded to all files found via the glob provided to PathExpander.

# File lib/path_expander.rb, line 49
def expand_dirs_to_files *dirs
  dirs.flatten.map { |p|
    if File.directory? p then
      Dir[File.join(p, glob)].find_all { |f| File.file? f }
    else
      p
    end
  }.flatten.sort
end

filter_files(files, ignore) click to toggle source

A file filter mechanism similar to, but not as extensive as, .gitignore files:

+ If a pattern does not contain a slash, it is treated as a shell glob. + If a pattern ends in a slash, it matches on directories (and contents). + Otherwise, it matches on relative paths.

File.fnmatch is used throughout, so glob patterns work for all 3 types.

Takes a list of files and either an io or path of ignore data and returns a list of files left after filtering.

# File lib/path_expander.rb, line 165
def filter_files files, ignore
  ignore_paths = if ignore.respond_to? :read then
                   ignore.read
                 elsif File.exist? ignore then
                   File.read ignore
                 end

  if ignore_paths then
    nonglobs, globs = ignore_paths.split("\n").partition { |p| p.include? "/" }
    dirs, ifiles    = nonglobs.partition { |p| p.end_with? "/" }
    dirs            = dirs.map { |s| s.chomp "/" }

    dirs.map!   { |i| File.expand_path i }
    globs.map!  { |i| File.expand_path i }
    ifiles.map! { |i| File.expand_path i }

    only_paths = File::FNM_PATHNAME
    files = files.reject { |f|
      f = File.expand_path(f)
      dirs.any?     { |i| File.fnmatch?(i, File.dirname(f), only_paths) } ||
        globs.any?  { |i| File.fnmatch?(i, f) } ||
        ifiles.any? { |i| File.fnmatch?(i, f, only_paths) }
    }
  end

  files
end

process() click to toggle source

Top-level method processes args. It replaces args’ contents with a new array of flags to process and returns a list of files to process. Eg

PathExpander.new(ARGV).process.each do |f|
  puts "./#{f}"
end

# File lib/path_expander.rb, line 144
def process
  files, flags = process_args

  args.replace process_flags flags

  files.uniq
end

process_args() click to toggle source

Enumerate over args passed to PathExpander and return a list of files and flags to process. Arguments are processed as:

@file_of_args: Read the file and append to args.
-file_path: Subtract path from file to be processed.
-dir_path: Expand and subtract paths from files to be processed.
-not_a_path: Add to flags to be processed.
dir_path: Expand and add to files to be processed.
file_path: Add to files to be processed.

Add “-” (stdin) to files to be processed.

See expand_dirs_to_files for details on how expansion occurs.

Subtraction happens last, regardless of argument ordering.

If no files are found (which is not the same as having an empty file list after subtraction), then fall back to expanding on the default path given to initialize.

# File lib/path_expander.rb, line 87
def process_args
  pos_files = []
  neg_files = []
  flags     = []
  clean     = true

  args.each do |arg|
    case arg
    when /^@(.*)/ then # push back on, so they can have dirs/-/@ as well
      clean = false
      args.concat process_file $1
    when "-" then
      pos_files << arg
    when /^-(.*)/ then
      if File.exist? $1 then
        clean = false
        neg_files += expand_dirs_to_files($1)
      else
        flags << arg
      end
    else
      root_path = File.expand_path(arg) == "/" # eg: -n /./
      if File.exist? arg and not root_path then
        clean = false
        pos_files += expand_dirs_to_files(arg)
      else
        flags << arg
      end
    end
  end

  files = pos_files - neg_files
  files += expand_dirs_to_files(self.path) if files.empty? && clean

  [files, flags]
end

process_file(path) click to toggle source

Process a file into more arguments. Override this to add additional capabilities.

# File lib/path_expander.rb, line 63
def process_file path
  File.readlines(path).map(&:chomp)
end

process_flags(flags) click to toggle source

Process over flags and treat any special ones here. Returns an array of the flags you haven’t processed.

This version does nothing. Subclass and override for customization.

# File lib/path_expander.rb, line 131
def process_flags flags
  flags
end