Option row_sep

Specifies the row separator, a String or the Symbol :auto (see below), to be used for both parsing and generating.

Default value:

CSV::DEFAULT_OPTIONS.fetch(:row_sep) # => :auto

When row_sep is a String, that String becomes the row separator. The String will be transcoded into the data’s Encoding before use.

Using "\n":

row_sep = "\n"
str = CSV.generate(row_sep: row_sep) do |csv|
  csv << [:foo, 0]
  csv << [:bar, 1]
  csv << [:baz, 2]
end
str # => "foo,0\nbar,1\nbaz,2\n"
ary = CSV.parse(str)
ary # => [["foo", "0"], ["bar", "1"], ["baz", "2"]]

Using | (pipe):

row_sep = '|'
str = CSV.generate(row_sep: row_sep) do |csv|
  csv << [:foo, 0]
  csv << [:bar, 1]
  csv << [:baz, 2]
end
str # => "foo,0|bar,1|baz,2|"
ary = CSV.parse(str, row_sep: row_sep)
ary # => [["foo", "0"], ["bar", "1"], ["baz", "2"]]

Using -- (two hyphens):

row_sep = '--'
str = CSV.generate(row_sep: row_sep) do |csv|
  csv << [:foo, 0]
  csv << [:bar, 1]
  csv << [:baz, 2]
end
str # => "foo,0--bar,1--baz,2--"
ary = CSV.parse(str, row_sep: row_sep)
ary # => [["foo", "0"], ["bar", "1"], ["baz", "2"]]

Using '' (empty string):

row_sep = ''
str = CSV.generate(row_sep: row_sep) do |csv|
  csv << [:foo, 0]
  csv << [:bar, 1]
  csv << [:baz, 2]
end
str # => "foo,0bar,1baz,2"
ary = CSV.parse(str, row_sep: row_sep)
ary # => [["foo", "0bar", "1baz", "2"]]

When row_sep is the Symbol :auto (the default), generating uses "\n" as the row separator:

str = CSV.generate do |csv|
  csv << [:foo, 0]
  csv << [:bar, 1]
  csv << [:baz, 2]
end
str # => "foo,0\nbar,1\nbaz,2\n"

Parsing, on the other hand, invokes auto-discovery of the row separator.

Auto-discovery reads ahead in the data looking for the next \r\n, \n, or \r sequence. The sequence will be selected even if it occurs in a quoted field, assuming that you would have the same line endings there.

Example:

str = CSV.generate do |csv|
  csv << [:foo, 0]
  csv << [:bar, 1]
  csv << [:baz, 2]
end
str # => "foo,0\nbar,1\nbaz,2\n"
ary = CSV.parse(str)
ary # => [["foo", "0"], ["bar", "1"], ["baz", "2"]]

The default $INPUT_RECORD_SEPARATOR ($/) is used if any of the following is true:

• None of those sequences is found.

• Data is ARGF, STDIN, STDOUT, or STDERR.

• The stream is only available for output.

Obviously, discovery takes a little time. Set manually if speed is important. Also note that IO objects should be opened in binary mode on Windows if this feature will be used as the line-ending translation can cause problems with resetting the document position to where it was before the read ahead.