method

open

v2_6_3 - Show latest stable - 0 notes - Class: CSV

open(filename, mode="r", **options) public

This method opens an IO object, and wraps that with CSV. This is intended as the primary interface for writing a CSV file.

You must pass a filename and may optionally add a mode for Ruby’s open(). You may also pass an optional Hash containing any options CSV::new() understands as the final argument.

This method works like Ruby’s open() call, in that it will pass a CSV object to a provided block and close it when the block terminates, or it will return the CSV object when no block is provided. (Note: This is different from the Ruby 1.8 CSV library which passed rows to the block. Use CSV::foreach() for that behavior.)

You must provide a mode with an embedded Encoding designator unless your data is in Encoding::default_external(). CSV will check the Encoding of the underlying IO object (set by the mode you pass) to determine how to parse the data. You may provide a second Encoding to have the data transcoded as it is read just as you can with a normal call to IO::open(). For example, "rb:UTF-32BE:UTF-8" would read UTF-32BE data from the file but transcode it to UTF-8 before CSV parses it.

An opened CSV object will delegate to many IO methods for convenience. You may call:

binmode()
binmode?()
close()
close_read()
close_write()
closed?()
eof()
eof?()
external_encoding()
fcntl()
fileno()
flock()
flush()
fsync()
internal_encoding()
ioctl()
isatty()
path()
pid()
pos()
pos=()
reopen()
seek()
stat()
sync()
sync=()
tell()
to_i()
to_io()
truncate()
tty?()

Show source

# File lib/csv.rb, line 633
  def self.open(filename, mode="r", **options)
    # wrap a File opened with the remaining +args+ with no newline
    # decorator
    file_opts = {universal_newline: false}.merge(options)

    begin
      f = File.open(filename, mode, file_opts)
    rescue ArgumentError => e
      raise unless /needs binmode/.match?(e.message) and mode == "r"
      mode = "rb"
      file_opts = {encoding: Encoding.default_external}.merge(file_opts)
      retry
    end
    begin
      csv = new(f, options)
    rescue Exception
      f.close
      raise
    end

    # handle blocks like Ruby's open(), not like the CSV library
    if block_given?
      begin
        yield csv
      ensure
        csv.close
      end
    else
      csv
    end
  end

open

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