Class: File

Inherits:
Object show all
Defined in:
lib/standard/facets/yaml.rb,
lib/core/facets/file/ext.rb,
lib/core/facets/file/null.rb,
lib/core/facets/file/write.rb,
lib/core/facets/file/append.rb,
lib/core/facets/file/create.rb,
lib/core/facets/file/rewrite.rb,
lib/core/facets/file/rootname.rb,
lib/core/facets/file/sanitize.rb,
lib/core/facets/file/read_list.rb,
lib/core/facets/file/split_all.rb,
lib/core/facets/file/split_root.rb,
lib/core/facets/file/writelines.rb,
lib/core/facets/file/read_binary.rb

Direct Known Subclasses

AtomicFile

Class Method Summary (collapse)

Class Method Details

+ (Object) append(file, str)

Append to a file.

CREDIT: George Moschovitis



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# File 'lib/core/facets/file/append.rb', line 7

def self.append(file, str)
  File.open(file, 'ab') { |f|
    f << str
  }
end

+ (Object) create(path, str = '',, &blk)

Creates a new file, or overwrites an existing file, and writes a string into it. Can also take a block just like File#open, which is yielded after the string is writ.

str = 'The content for the file'
File.create('myfile.txt', str)

CREDIT: George Moschovitis



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# File 'lib/core/facets/file/create.rb', line 13

def self.create(path, str='', &blk)
  open(path, 'wb') do |f|
    f << str
    blk.call(f) if blk
  end
end

+ (Object) ext(filename, new_ext = nil)

Takes a file name string and returns or changes its extension.

Without a new extension argument, returns the extension of the file name. In this respect #ext is like #extname, but unlike #extname it does not include the dot prefix.

With a new extension argument, changes the exension of the file name to the new extension and returns it.

Examples

File.ext('file.rb')          # => 'rb'
File.ext('file.rb', 'txt')   # => 'file.txt'
File.ext('file.rb', '.txt')  # => 'file.txt'
File.ext('file.rb', '')      # => 'file'

This method can be used with String#file for more object-oriented notation:

'file.rb'.file.ext('txt')    # => 'file.txt'

CREDIT: Lavir the Whiolet



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# File 'lib/core/facets/file/ext.rb', line 25

def self.ext(filename, new_ext=nil)
  old_ext = extname(filename)
  if new_ext == nil
    old_ext.sub(/^\./, '')
  else
    new_ext = '.' + new_ext unless (new_ext.empty? || new_ext[0,1] == '.')
    filename.chomp(old_ext) + new_ext
  end
end

+ (Object) null

Platform dependent null device.

CREDIT: Daniel Burger



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# File 'lib/core/facets/file/null.rb', line 7

def self.null
  case RUBY_PLATFORM
  when /mswin/i
    'NUL'
  when /amiga/i
    'NIL:'
  when /openvms/i
    'NL:'
  else
    '/dev/null'
  end
end

+ (Object) read_binary(fname)

Read in a file as binary data.

Assuming we had a binary file 'binary.dat'.

File.read_binary('binary.dat')

CREDIT: George Moschovitis



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# File 'lib/core/facets/file/read_binary.rb', line 11

def self.read_binary(fname)
  open(fname, 'rb') do |f|
    return f.read
  end
end

+ (Object) read_list(filepath, options = {})

Reads in a file, removes blank lines and removes lines starting with '#' and then returns an array of all the remaining lines.

Thr remark indicator can be overridden via the :omit: option, which can be a regualar expression or a string that is match against the start of a line.

CREDIT: Trans



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# File 'lib/core/facets/file/read_list.rb', line 12

def self.read_list(filepath, options={})
  chomp = options[:chomp]
  omit  = case options[:omit]
          when Regexp
            omit
          when nil
            /^\s*\#/
          else
            /^\s*#{Regexp.escape(omit)}/
          end

  list = []
  readlines(filepath).each do |line|
    line = line.strip.chomp(chomp)
    next if line.empty?
    next if omit === line
    list << line
  end
  list
end

+ (Object) rewrite(name, mode = ""))

Opens a file as a string and writes back the string to the file at the end of the block.

Returns the number of written bytes or nil if the file wasn't modified.

Note that the file will even be written back in case the block raises an exception.

Mode can either be "b" or "+" and specifies to open the file in binary mode (no mapping of the plattform's newlines to "n" is done) or to append to it.

Assuming we had a file 'message.txt' and had a binary file 'binary.dat'.

# Reverse contents of "message.txt"
File.rewrite("message.txt") { |str| str.reverse }

# Replace "foo" by "bar" in "binary.dat".
File.rewrite("binary.dat", "b") { |str| str.gsub("foo", "bar") }

IMPORTANT: The old version of this method required in place modification of the file string. The new version will write whatever the block returns instead!!!

CREDIT: George Moschovitis



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# File 'lib/core/facets/file/rewrite.rb', line 30

def self.rewrite(name, mode = "") #:yield:
  unless block_given?
    raise(ArgumentError, "Need to supply block to File.rewrite")
  end

  if mode.is_a?(Numeric) then
    flag, mode = mode, ""
    mode += "b" if flag & File::Constants::BINARY != 0
    mode += "+" if flag & File::Constants::APPEND != 0
  else
    mode.delete!("^b+")
  end

  old_str = open(name, "r#{mode}") { |file| file.read } #rescue ""
  old_str = old_str.clone

  begin
    new_str = yield(old_str)
  ensure
    if old_str != new_str
      open(name, "w#{mode}") { |file| file.write(new_str) }
    end
  end
end

+ (Object) rewrite!(name, mode = ""))

In place version of #rewrite. This version of method requires that the string be modified in place within the block.

# Reverse contents of "message"
File.rewrite("message.txt") { |str| str.reverse! }

# Replace "foo" by "bar" in "binary"
File.rewrite("binary.dat", "b") { |str| str.gsub!("foo", "bar") }


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# File 'lib/core/facets/file/rewrite.rb', line 64

def self.rewrite!(name, mode = "") #:yield:
  unless block_given?
    raise(ArgumentError, "Need to supply block to File.rewrite")
  end

  if mode.is_a?(Numeric) then
    flag, mode = mode, ""
    mode += "b" if flag & File::Constants::BINARY != 0
    mode += "+" if flag & File::Constants::APPEND != 0
  else
    mode.delete!("^b+")
  end

  old_str = open(name, "r#{mode}") { |file| file.read } #rescue ""
  new_str = old_str.clone

  begin
    yield(new_str)
  ensure
    if old_str != new_str
      open(name, "w#{mode}") { |file| file.write(new_str) }
    end
  end
end

+ (Object) rootname(path)

Returns only the first portion of the directory of a file path name.

File.rootname('lib/jump.rb')  #=> 'lib'
File.rootname('/jump.rb')     #=> '/'
File.rootname('jump.rb')      #=> '.'

CREDIT: Trans



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# File 'lib/core/facets/file/rootname.rb', line 12

def self.rootname(path)
  # -- this should be fairly robust
  path_re = Regexp.new('[' + Regexp.escape(File::Separator + %q{\/}) + ']')

  head, tail = path.split(path_re, 2)
  return '.' if path == head
  return '/' if head.empty?
  return head
end

+ (Object) sanitize(filename)

Cleans up a filename to ensure it will work on a filesystem.

File.sanitize("yo+baby!")   #=> 'yo+baby_'
File.sanitize(".what&up")  #=> '.what_up'

CREDIT: George Moschovitis



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# File 'lib/core/facets/file/sanitize.rb', line 10

def self.sanitize(filename)
  filename = File.basename(filename.gsub("\\", "/")) # work-around for IE
  filename.gsub!(/[^a-zA-Z0-9\.\-\+_]/,"_")
  filename = "_#{filename}" if filename =~ /^\.+$/
  filename
end

+ (Object) split_all(path)

Splits a file path into an array of individual path components. This differs from File.split, which divides the path into only two parts, directory path and basename.

File.split_all("a/b/c")  #=> ['a', 'b', 'c']

CREDIT: Trans



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# File 'lib/core/facets/file/split_all.rb', line 11

def self.split_all(path)
  head, tail = File.split(path)
  return [tail] if head == '.' || tail == '/'
  return [head, tail] if head == '/'
  return split_all(head) + [tail]
end

+ (Object) split_root(path)

Return the head of path from the rest of the path.

File.split_root('etc/xdg/gtk')  #=> ['etc', 'xdg/gtk']


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# File 'lib/core/facets/file/split_root.rb', line 7

def self.split_root(path)
  path_re = Regexp.new('[' + Regexp.escape(File::Separator + %q{\/}) + ']')
  path.split(path_re, 2)
end

+ (Object) write(path, data)

Writes the given data to the given path and closes the file. This is done in binary mode, complementing IO.read in standard Ruby.

str = 'The content for the file'
File.write('write.txt', str)

Returns the number of bytes written.

CREDIT: Gavin Sinclair



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# File 'lib/core/facets/file/write.rb', line 15

def self.write(path, data)
  File.open(path, "wb") do |file|
    return file.write(data)
  end
end

+ (Object) writelines(path, data)

Writes the given array of data to the given path and closes the file. This is done in binary mode, complementing IO.readlines in standard Ruby.

Note that readlines (the standard Ruby method) returns an array of lines with newlines intact, whereas writelines uses puts, and so appends newlines if necessary. In this small way, readlines and writelines are not exact opposites.

data = ['The content', ['for the file']]
File.writelines('writelines.txt', data)

Returns number of lines written.

CREDIT: Noah Gibbs, Gavin Sinclair



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# File 'lib/core/facets/file/writelines.rb', line 19

def self.writelines(path, data)
  File.open(path, "wb") do |file|
    file.puts(data)
  end
  data.size
end

+ (Boolean) yaml?(file)

File.yaml? provides a way to check if a file is a YAML formatted file:

File.yaml?('project.yaml')  #=> true
File.yaml?('project.xml')   #=> false

Note this isn't perfect. At present it depends on the use use of an initial document separator (eg. '---'). With YAML 1.1 the %YAML delaration is supposed to be manditory, so in the future this can be adapted to fit that standard.

Returns:

  • (Boolean) 


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# File 'lib/standard/facets/yaml.rb', line 39

def self.yaml?(file)
  File.open(file) do |f|
    until f.eof?
      line = f.gets
      break true if line =~ /^---/
      break false unless line =~ /^(\s*#.*?|\s*)$/
    end
  end
end