Class: File

Inherits:
Object show all
Defined in:
lib/amp/dependencies/zip/stdrubyext.rb,
lib/amp/support/ruby_19_compatibility.rb,
lib/amp/support/support.rb

Direct Known Subclasses

BugFix::Tempfile

Defined Under Namespace

Classes: Stat

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.amp_atomic_write(file_name, mode = 'w', default_mode = nil, temp_dir = Dir.tmpdir, &block) ⇒ Object

taken from Rails’ ActiveSupport all or nothing babyyyyyyyy use this only for writes, otherwise it’s just inefficient file_name is FULL PATH



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# File 'lib/amp/support/support.rb', line 350

def self.amp_atomic_write(file_name, mode='w', default_mode=nil, temp_dir=Dir.tmpdir, &block)
  File.makedirs(File.dirname(file_name))
  FileUtils.touch(file_name) unless File.exists? file_name
  # this is sorta like "checking out" a file
  # but only if we're *just* writing
  new_path = join temp_dir, amp_make_tmpname(basename(file_name))
  unless mode == 'w'
    copy(file_name, new_path) # allowing us to use mode "a" and others
  end

  
  # open and close it
  val = Kernel::open new_path, mode, &block
  
  begin
    # Get original file permissions
    old_stat = stat(file_name)
  rescue Errno::ENOENT
    # No old permissions, write a temp file to determine the defaults
    check_name = ".permissions_check.#{Thread.current.object_id}.#{Process.pid}.#{rand(1000000)}"
    Kernel::open(check_name, "w") { }
    old_stat = stat(check_name)
    unlink(check_name)
    delete(check_name)
  end
  
  # do a chmod, pretty much
  begin
    nlink = File.amp_num_hardlinks(file_name)
  rescue Errno::ENOENT, OSError
    nlink = 0
    d = File.dirname(file_name)
    File.mkdir_p(d, default_mode) unless File.directory? d
  end
  
  new_mode = default_mode & 0666 if default_mode
  
  # Overwrite original file with temp file
  amp_force_rename(new_path, file_name)
  
  # Set correct permissions on new file
  chown(old_stat.uid, old_stat.gid, file_name)
  chmod(new_mode || old_stat.mode, file_name)
  
  val
end

.amp_directories_to(path, empty = false) ⇒ Array

All directories leading up to this path

Examples:

directories_to “/Users/ari/src/monkey.txt” # =>

["/Users/ari/src", "/Users/ari", "/Users"]

directories_to “/Users/ari/src/monkey.txt”, true # =>

["/Users/ari/src", "/Users/ari", "/Users", ""]

Parameters:

  • path (String) —

    the path to the file we’re examining

  • empty (Boolean) (defaults to: false) —

    whether or not to return an empty string as well

Returns:

  • (Array) —

    the directories leading up to this path



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# File 'lib/amp/support/support.rb', line 466

def self.amp_directories_to(path, empty=false)
  dirs = path.split('/')[0..-2]
  ret  = []
  
  dirs.size.times { ret << dirs.join('/'); dirs.pop }
  ret << '' if empty
  ret
end

.amp_find_executable(command) ⇒ String?

TODO:

Add Windows Version.

Finds an executable for Amp::KernelMethods#command. Searches like the OS does. If command is a basename then PATH is searched for Amp::KernelMethods#command. PATH isn’t searched if command is an absolute or relative path. If command isn’t found, nil is returned. *nix only.

Parameters:

  • command (String) —

    the executable to find

Returns:

  • (String, nil) —

    If the executable is found, the full path is returned.



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# File 'lib/amp/support/support.rb', line 330

def self.amp_find_executable(command)
  find_if_exists = proc do |executable|
    return executable if File.exist? executable
    return nil
  end
  
  return find_if_exists[command] if command.include?(File::SEPARATOR)
  ENV["PATH"].split(File::PATH_SEPARATOR).each do |path|
    executable = find_if_exists[File.join(path, command)]
    return executable if executable
  end
  
  nil
end

.amp_force_rename(file, dst) ⇒ Object

Forces a rename from file to dst, removing the dst file if it already exists. Avoids system exceptions that might result.

Parameters:

  • file (String) —

    the source file path

  • dst (String) —

    the destination file path



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# File 'lib/amp/support/support.rb', line 481

def self.amp_force_rename(file, dst)
  return unless File.exist? file
  if File.exist? dst
    File.unlink dst
    File.rename file, dst
  else
    File.rename file, dst
  end
end

.amp_lookup_reg(a, b) ⇒ Object

TODO:

Add Windows Version

Does a registry lookup. *nix version.



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# File 'lib/amp/support/support.rb', line 317

def self.amp_lookup_reg(a,b)
  nil
end

.amp_make_tmpname(basename) ⇒ String

Makes a fancy, quite-random name for a temporary file. Uses the file’s name, the current time, the process number, a random number, and the file’s extension to make a very random filename.

Of course, it could still fail.

Parameters:

  • basename (String) —

    The base name of the file - just the file’s name and extension

Returns:

  • (String) —

    the pseudo-random name of the file to be created



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# File 'lib/amp/support/support.rb', line 406

def self.amp_make_tmpname(basename)
  case basename
  when Array
    prefix, suffix = *basename
  else
    prefix, suffix = basename, "."+File.extname(basename)
  end

  t = Time.now.strftime("%Y%m%d")
  path = "#{prefix}#{t}-#{$$}-#{rand(0x100000000).to_s(36)}-#{suffix}"
end

.amp_name(file) ⇒ Object

Returns the full name of the file, excluding path information.

Parameters:

Returns:

  • the name of the file



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# File 'lib/amp/support/support.rb', line 496

def self.amp_name(file)
  File.split(file.path).last
end

.amp_num_hardlinks(file) ⇒ Integer

Finds the number of hard links to the file.

Parameters:

  • file (String) —

    the full path to the file to lookup

Returns:

  • (Integer) —

    the number of hard links to the file

Raises:



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# File 'lib/amp/support/support.rb', line 450

def self.amp_num_hardlinks(file)
  lstat = File.lstat(file)
  raise OSError.new("no lstat on windows") if lstat.nil?
  lstat.nlink
end

.amp_set_executable(path, executable) ⇒ Object

TODO:

Windows version

Sets a file’s executable bit.

Parameters:

  • path (String) —

    the path to the file

  • executable (Boolean) —

    sets whether the file is executable or not



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# File 'lib/amp/support/support.rb', line 300

def self.amp_set_executable(path, executable)
  s = File.lstat(path).mode
  sx = s & 0100
  if executable && !sx
    # Turn on +x for every +r bit when making a file executable
    # and obey umask. (direct from merc. source)
    File.chmod(s | (s & 0444) >> 2 & ~(File.umask(0)), path)
  elsif !executable && sx
    File.chmod(s & 0666 , path)
  end
end

.amp_split_extension(path) ⇒ String

Splits the path into two parts: pre-extension, and extension, including the dot. File.amp_split_extension “/usr/bin/conf.ini” => [“conf”,“.ini”]

Parameters:

  • path (String) —

    the path to the file to split up

Returns:

  • (String, String) —

    the [filename pre extension, file extension] of the file provided.



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# File 'lib/amp/support/support.rb', line 508

def self.amp_split_extension(path)
  ext  = File.extname  path
  base = File.basename path, ext
  [base, ext]
end

.copy(*args) ⇒ Object

This is in ftools in Ruby 1.8.x, but now it’s in FileUtils. So this is essentially an alias to it. Silly ftools, trix are for kids.



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# File 'lib/amp/support/ruby_19_compatibility.rb', line 53

def self.copy(*args)
  FileUtils.copy(*args)
end

.makedirs(*args) ⇒ Object

This is in ftools in Ruby 1.8.x, but now it’s in FileUtils. So this is essentially an alias to it. Silly ftools, trix are for kids.



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# File 'lib/amp/support/ruby_19_compatibility.rb', line 65

def self.makedirs(*args)
  FileUtils.makedirs(*args)
end

.move(*args) ⇒ Object

This is in ftools in Ruby 1.8.x, but now it’s in FileUtils. So this is essentially an alias to it. Silly ftools, trix are for kids.



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# File 'lib/amp/support/ruby_19_compatibility.rb', line 59

def self.move(*args)
  FileUtils.move(*args)
end

.read(fileName) ⇒ Object

singleton method read does not exist in 1.6.x



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# File 'lib/amp/dependencies/zip/stdrubyext.rb', line 29

def self.read(fileName)
  open(fileName) { |f| f.read }
end

Instance Method Details

#[](range) ⇒ String

Reads a range from the file.

Parameters:

  • range (Range) —

    the byte indices to read between (and including)

Returns:

  • (String) —

    the data read from the file



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# File 'lib/amp/support/support.rb', line 423

def [](range)
  p = pos
  seek(range.first)
  val = read(range.last - range.first + 1)
  seek p
  val
end

#amp_each_chunk(num_bytes = 4.kb) {|the| ... } ⇒ Object

Reads n bytes at a time and yield them from the given file

Parameters:

  • num_bytes (Integer) (defaults to: 4.kb) —

    the number of bytes to yield

Yields:

  • Yields a chunk that is at most num_bytes from the file until the file is exhausted. Poor file, it’s so tired.

Yield Parameters:

  • the (String) —

    chunk from the file.



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# File 'lib/amp/support/support.rb', line 438

def amp_each_chunk(num_bytes = 4.kb)
  buffer = nil
  while buffer = read(num_bytes)
    yield buffer
  end
end

#amp_lexist?(filename) ⇒ Boolean

Checks if a file exists, without following symlinks.

Parameters:

  • filename (String) —

    the path to the file to check

Returns:

  • (Boolean) —

    whether or not the file exists (ignoring symlinks)



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# File 'lib/amp/support/support.rb', line 290

def amp_lexist?(filename)
  !!File.lstat(filename) rescue false
end