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Edit File: csv.rb
# CSV -- module for generating/parsing CSV data. # Copyright (C) 2000-2004 NAKAMURA, Hiroshi <nakahiro@sarion.co.jp>. # $Id: csv.rb 11708 2007-02-12 23:01:19Z shyouhei $ # This program is copyrighted free software by NAKAMURA, Hiroshi. You can # redistribute it and/or modify it under the same terms of Ruby's license; # either the dual license version in 2003, or any later version. class CSV class IllegalFormatError < RuntimeError; end # deprecated class Cell < String def initialize(data = "", is_null = false) super(is_null ? "" : data) end def data to_s end end # deprecated class Row < Array end # Open a CSV formatted file for reading or writing. # # For reading. # # EXAMPLE 1 # CSV.open('csvfile.csv', 'r') do |row| # p row # end # # EXAMPLE 2 # reader = CSV.open('csvfile.csv', 'r') # row1 = reader.shift # row2 = reader.shift # if row2.empty? # p 'row2 not find.' # end # reader.close # # ARGS # filename: filename to parse. # col_sep: Column separator. ?, by default. If you want to separate # fields with semicolon, give ?; here. # row_sep: Row separator. nil by default. nil means "\r\n or \n". If you # want to separate records with \r, give ?\r here. # # RETURNS # reader instance. To get parse result, see CSV::Reader#each. # # # For writing. # # EXAMPLE 1 # CSV.open('csvfile.csv', 'w') do |writer| # writer << ['r1c1', 'r1c2'] # writer << ['r2c1', 'r2c2'] # writer << [nil, nil] # end # # EXAMPLE 2 # writer = CSV.open('csvfile.csv', 'w') # writer << ['r1c1', 'r1c2'] << ['r2c1', 'r2c2'] << [nil, nil] # writer.close # # ARGS # filename: filename to generate. # col_sep: Column separator. ?, by default. If you want to separate # fields with semicolon, give ?; here. # row_sep: Row separator. nil by default. nil means "\r\n or \n". If you # want to separate records with \r, give ?\r here. # # RETURNS # writer instance. See CSV::Writer#<< and CSV::Writer#add_row to know how # to generate CSV string. # def CSV.open(path, mode, fs = nil, rs = nil, &block) if mode == 'r' or mode == 'rb' open_reader(path, mode, fs, rs, &block) elsif mode == 'w' or mode == 'wb' open_writer(path, mode, fs, rs, &block) else raise ArgumentError.new("'mode' must be 'r', 'rb', 'w', or 'wb'") end end def CSV.foreach(path, rs = nil, &block) open_reader(path, 'r', ',', rs, &block) end def CSV.read(path, length = nil, offset = nil) CSV.parse(IO.read(path, length, offset)) end def CSV.readlines(path, rs = nil) reader = open_reader(path, 'r', ',', rs) begin reader.collect { |row| row } ensure reader.close end end def CSV.generate(path, fs = nil, rs = nil, &block) open_writer(path, 'w', fs, rs, &block) end # Parse lines from given string or stream. Return rows as an Array of Arrays. def CSV.parse(str_or_readable, fs = nil, rs = nil, &block) if File.exist?(str_or_readable) STDERR.puts("CSV.parse(filename) is deprecated." + " Use CSV.open(filename, 'r') instead.") return open_reader(str_or_readable, 'r', fs, rs, &block) end if block CSV::Reader.parse(str_or_readable, fs, rs) do |row| yield(row) end nil else CSV::Reader.create(str_or_readable, fs, rs).collect { |row| row } end end # Parse a line from given string. Bear in mind it parses ONE LINE. Rest of # the string is ignored for example "a,b\r\nc,d" => ['a', 'b'] and the # second line 'c,d' is ignored. # # If you don't know whether a target string to parse is exactly 1 line or # not, use CSV.parse_row instead of this method. def CSV.parse_line(src, fs = nil, rs = nil) fs ||= ',' if fs.is_a?(Fixnum) fs = fs.chr end if !rs.nil? and rs.is_a?(Fixnum) rs = rs.chr end idx = 0 res_type = :DT_COLSEP row = [] begin while res_type == :DT_COLSEP res_type, idx, cell = parse_body(src, idx, fs, rs) row << cell end rescue IllegalFormatError return [] end row end # Create a line from cells. each cell is stringified by to_s. def CSV.generate_line(row, fs = nil, rs = nil) if row.size == 0 return '' end fs ||= ',' if fs.is_a?(Fixnum) fs = fs.chr end if !rs.nil? and rs.is_a?(Fixnum) rs = rs.chr end res_type = :DT_COLSEP result_str = '' idx = 0 while true generate_body(row[idx], result_str, fs, rs) idx += 1 if (idx == row.size) break end generate_separator(:DT_COLSEP, result_str, fs, rs) end result_str end # Parse a line from string. Consider using CSV.parse_line instead. # To parse lines in CSV string, see EXAMPLE below. # # EXAMPLE # src = "a,b\r\nc,d\r\ne,f" # idx = 0 # begin # parsed = [] # parsed_cells, idx = CSV.parse_row(src, idx, parsed) # puts "Parsed #{ parsed_cells } cells." # p parsed # end while parsed_cells > 0 # # ARGS # src: a CSV data to be parsed. Must respond '[](idx)'. # src[](idx) must return a char. (Not a string such as 'a', but 97). # src[](idx_out_of_bounds) must return nil. A String satisfies this # requirement. # idx: index of parsing location of 'src'. 0 origin. # out_dev: buffer for parsed cells. Must respond '<<(aString)'. # col_sep: Column separator. ?, by default. If you want to separate # fields with semicolon, give ?; here. # row_sep: Row separator. nil by default. nil means "\r\n or \n". If you # want to separate records with \r, give ?\r here. # # RETURNS # parsed_cells: num of parsed cells. # idx: index of next parsing location of 'src'. # def CSV.parse_row(src, idx, out_dev, fs = nil, rs = nil) fs ||= ',' if fs.is_a?(Fixnum) fs = fs.chr end if !rs.nil? and rs.is_a?(Fixnum) rs = rs.chr end idx_backup = idx parsed_cells = 0 res_type = :DT_COLSEP begin while res_type != :DT_ROWSEP res_type, idx, cell = parse_body(src, idx, fs, rs) if res_type == :DT_EOS if idx == idx_backup #((parsed_cells == 0) and cell.nil?) return 0, 0 end res_type = :DT_ROWSEP end parsed_cells += 1 out_dev << cell end rescue IllegalFormatError return 0, 0 end return parsed_cells, idx end # Convert a line from cells data to string. Consider using CSV.generate_line # instead. To generate multi-row CSV string, see EXAMPLE below. # # EXAMPLE # row1 = ['a', 'b'] # row2 = ['c', 'd'] # row3 = ['e', 'f'] # src = [row1, row2, row3] # buf = '' # src.each do |row| # parsed_cells = CSV.generate_row(row, 2, buf) # puts "Created #{ parsed_cells } cells." # end # p buf # # ARGS # src: an Array of String to be converted to CSV string. Must respond to # 'size' and '[](idx)'. src[idx] must return String. # cells: num of cells in a line. # out_dev: buffer for generated CSV string. Must respond to '<<(string)'. # col_sep: Column separator. ?, by default. If you want to separate # fields with semicolon, give ?; here. # row_sep: Row separator. nil by default. nil means "\r\n or \n". If you # want to separate records with \r, give ?\r here. # # RETURNS # parsed_cells: num of converted cells. # def CSV.generate_row(src, cells, out_dev, fs = nil, rs = nil) fs ||= ',' if fs.is_a?(Fixnum) fs = fs.chr end if !rs.nil? and rs.is_a?(Fixnum) rs = rs.chr end src_size = src.size if (src_size == 0) if cells == 0 generate_separator(:DT_ROWSEP, out_dev, fs, rs) end return 0 end res_type = :DT_COLSEP parsed_cells = 0 generate_body(src[parsed_cells], out_dev, fs, rs) parsed_cells += 1 while ((parsed_cells < cells) and (parsed_cells != src_size)) generate_separator(:DT_COLSEP, out_dev, fs, rs) generate_body(src[parsed_cells], out_dev, fs, rs) parsed_cells += 1 end if (parsed_cells == cells) generate_separator(:DT_ROWSEP, out_dev, fs, rs) else generate_separator(:DT_COLSEP, out_dev, fs, rs) end parsed_cells end # Private class methods. class << self private def open_reader(path, mode, fs, rs, &block) file = File.open(path, mode) if block begin CSV::Reader.parse(file, fs, rs) do |row| yield(row) end ensure file.close end nil else reader = CSV::Reader.create(file, fs, rs) reader.close_on_terminate reader end end def open_writer(path, mode, fs, rs, &block) file = File.open(path, mode) if block begin CSV::Writer.generate(file, fs, rs) do |writer| yield(writer) end ensure file.close end nil else writer = CSV::Writer.create(file, fs, rs) writer.close_on_terminate writer end end def parse_body(src, idx, fs, rs) fs_str = fs fs_size = fs_str.size rs_str = rs || "\n" rs_size = rs_str.size fs_idx = rs_idx = 0 cell = Cell.new state = :ST_START quoted = cr = false c = nil last_idx = idx while c = src[idx] unless quoted fschar = (c == fs_str[fs_idx]) rschar = (c == rs_str[rs_idx]) # simple 1 char backtrack if !fschar and c == fs_str[0] fs_idx = 0 fschar = true if state == :ST_START state = :ST_DATA elsif state == :ST_QUOTE raise IllegalFormatError end end if !rschar and c == rs_str[0] rs_idx = 0 rschar = true if state == :ST_START state = :ST_DATA elsif state == :ST_QUOTE raise IllegalFormatError end end end if c == ?" fs_idx = rs_idx = 0 if cr raise IllegalFormatError end cell << src[last_idx, (idx - last_idx)] last_idx = idx if state == :ST_DATA if quoted last_idx += 1 quoted = false state = :ST_QUOTE else raise IllegalFormatError end elsif state == :ST_QUOTE cell << c.chr last_idx += 1 quoted = true state = :ST_DATA else # :ST_START quoted = true last_idx += 1 state = :ST_DATA end elsif fschar or rschar if fschar fs_idx += 1 end if rschar rs_idx += 1 end sep = nil if fs_idx == fs_size if state == :ST_START and rs_idx > 0 and fs_idx < rs_idx state = :ST_DATA end cell << src[last_idx, (idx - last_idx - (fs_size - 1))] last_idx = idx fs_idx = rs_idx = 0 if cr raise IllegalFormatError end sep = :DT_COLSEP elsif rs_idx == rs_size if state == :ST_START and fs_idx > 0 and rs_idx < fs_idx state = :ST_DATA end if !(rs.nil? and cr) cell << src[last_idx, (idx - last_idx - (rs_size - 1))] last_idx = idx end fs_idx = rs_idx = 0 sep = :DT_ROWSEP end if sep if state == :ST_DATA return sep, idx + 1, cell; elsif state == :ST_QUOTE return sep, idx + 1, cell; else # :ST_START return sep, idx + 1, nil end end elsif rs.nil? and c == ?\r # special \r treatment for backward compatibility fs_idx = rs_idx = 0 if cr raise IllegalFormatError end cell << src[last_idx, (idx - last_idx)] last_idx = idx if quoted state = :ST_DATA else cr = true end else fs_idx = rs_idx = 0 if state == :ST_DATA or state == :ST_START if cr raise IllegalFormatError end state = :ST_DATA else # :ST_QUOTE raise IllegalFormatError end end idx += 1 end if state == :ST_START if fs_idx > 0 or rs_idx > 0 state = :ST_DATA else return :DT_EOS, idx, nil end elsif quoted raise IllegalFormatError elsif cr raise IllegalFormatError end cell << src[last_idx, (idx - last_idx)] last_idx = idx return :DT_EOS, idx, cell end def generate_body(cell, out_dev, fs, rs) if cell.nil? # empty else cell = cell.to_s row_data = cell.dup if (row_data.gsub!('"', '""') or row_data.index(fs) or (rs and row_data.index(rs)) or (/[\r\n]/ =~ row_data) or (cell.empty?)) out_dev << '"' << row_data << '"' else out_dev << row_data end end end def generate_separator(type, out_dev, fs, rs) case type when :DT_COLSEP out_dev << fs when :DT_ROWSEP out_dev << (rs || "\n") end end end # CSV formatted string/stream reader. # # EXAMPLE # read CSV lines untill the first column is 'stop'. # # CSV::Reader.parse(File.open('bigdata', 'rb')) do |row| # p row # break if !row[0].is_null && row[0].data == 'stop' # end # class Reader include Enumerable # Parse CSV data and get lines. Given block is called for each parsed row. # Block value is always nil. Rows are not cached for performance reason. def Reader.parse(str_or_readable, fs = ',', rs = nil, &block) reader = Reader.create(str_or_readable, fs, rs) if block reader.each do |row| yield(row) end reader.close nil else reader end end # Returns reader instance. def Reader.create(str_or_readable, fs = ',', rs = nil) case str_or_readable when IO IOReader.new(str_or_readable, fs, rs) when String StringReader.new(str_or_readable, fs, rs) else IOReader.new(str_or_readable, fs, rs) end end def each while true row = [] parsed_cells = get_row(row) if parsed_cells == 0 break end yield(row) end nil end def shift row = [] parsed_cells = get_row(row) row end def close terminate end private def initialize(dev) raise RuntimeError.new('Do not instanciate this class directly.') end def get_row(row) raise NotImplementedError.new('Method get_row must be defined in a derived class.') end def terminate # Define if needed. end end class StringReader < Reader def initialize(string, fs = ',', rs = nil) @fs = fs @rs = rs @dev = string @idx = 0 if @dev[0, 3] == "\xef\xbb\xbf" @idx += 3 end end private def get_row(row) parsed_cells, next_idx = CSV.parse_row(@dev, @idx, row, @fs, @rs) if parsed_cells == 0 and next_idx == 0 and @idx != @dev.size raise IllegalFormatError.new end @idx = next_idx parsed_cells end end class IOReader < Reader def initialize(io, fs = ',', rs = nil) @io = io @fs = fs @rs = rs @dev = CSV::IOBuf.new(@io) @idx = 0 if @dev[0] == 0xef and @dev[1] == 0xbb and @dev[2] == 0xbf @idx += 3 end @close_on_terminate = false end # Tell this reader to close the IO when terminated (Triggered by invoking # CSV::IOReader#close). def close_on_terminate @close_on_terminate = true end private def get_row(row) parsed_cells, next_idx = CSV.parse_row(@dev, @idx, row, @fs, @rs) if parsed_cells == 0 and next_idx == 0 and !@dev.is_eos? raise IllegalFormatError.new end dropped = @dev.drop(next_idx) @idx = next_idx - dropped parsed_cells end def terminate if @close_on_terminate @io.close end if @dev @dev.close end end end # CSV formatted string/stream writer. # # EXAMPLE # Write rows to 'csvout' file. # # outfile = File.open('csvout', 'wb') # CSV::Writer.generate(outfile) do |csv| # csv << ['c1', nil, '', '"', "\r\n", 'c2'] # ... # end # # outfile.close # class Writer # Given block is called with the writer instance. str_or_writable must # handle '<<(string)'. def Writer.generate(str_or_writable, fs = ',', rs = nil, &block) writer = Writer.create(str_or_writable, fs, rs) if block yield(writer) writer.close nil else writer end end # str_or_writable must handle '<<(string)'. def Writer.create(str_or_writable, fs = ',', rs = nil) BasicWriter.new(str_or_writable, fs, rs) end # dump CSV stream to the device. argument must be an Array of String. def <<(row) CSV.generate_row(row, row.size, @dev, @fs, @rs) self end alias add_row << def close terminate end private def initialize(dev) raise RuntimeError.new('Do not instanciate this class directly.') end def terminate # Define if needed. end end class BasicWriter < Writer def initialize(str_or_writable, fs = ',', rs = nil) @fs = fs @rs = rs @dev = str_or_writable @close_on_terminate = false end # Tell this writer to close the IO when terminated (Triggered by invoking # CSV::BasicWriter#close). def close_on_terminate @close_on_terminate = true end private def terminate if @close_on_terminate @dev.close end end end private # Buffered stream. # # EXAMPLE 1 -- an IO. # class MyBuf < StreamBuf # # Do initialize myself before a super class. Super class might call my # # method 'read'. (Could be awful for C++ user. :-) # def initialize(s) # @s = s # super() # end # # # define my own 'read' method. # # CAUTION: Returning nil means EnfOfStream. # def read(size) # @s.read(size) # end # # # release buffers. in Ruby which has GC, you do not have to call this... # def terminate # @s = nil # super() # end # end # # buf = MyBuf.new(STDIN) # my_str = '' # p buf[0, 0] # => '' (null string) # p buf[0] # => 97 (char code of 'a') # p buf[0, 1] # => 'a' # my_str = buf[0, 5] # p my_str # => 'abcde' (5 chars) # p buf[0, 6] # => "abcde\n" (6 chars) # p buf[0, 7] # => "abcde\n" (6 chars) # p buf.drop(3) # => 3 (dropped chars) # p buf.get(0, 2) # => 'de' (2 chars) # p buf.is_eos? # => false (is not EOS here) # p buf.drop(5) # => 3 (dropped chars) # p buf.is_eos? # => true (is EOS here) # p buf[0] # => nil (is EOS here) # # EXAMPLE 2 -- String. # This is a conceptual example. No pros with this. # # class StrBuf < StreamBuf # def initialize(s) # @str = s # @idx = 0 # super() # end # # def read(size) # str = @str[@idx, size] # @idx += str.size # str # end # end # class StreamBuf # get a char or a partial string from the stream. # idx: index of a string to specify a start point of a string to get. # unlike String instance, idx < 0 returns nil. # n: size of a string to get. # returns char at idx if n == nil. # returns a partial string, from idx to (idx + n) if n != nil. at EOF, # the string size could not equal to arg n. def [](idx, n = nil) if idx < 0 return nil end if (idx_is_eos?(idx)) if n and (@offset + idx == buf_size(@cur_buf)) # Like a String, 'abc'[4, 1] returns nil and # 'abc'[3, 1] returns '' not nil. return '' else return nil end end my_buf = @cur_buf my_offset = @offset next_idx = idx while (my_offset + next_idx >= buf_size(my_buf)) if (my_buf == @buf_tail_idx) unless add_buf break end end next_idx = my_offset + next_idx - buf_size(my_buf) my_buf += 1 my_offset = 0 end loc = my_offset + next_idx if !n return @buf_list[my_buf][loc] # Fixnum of char code. elsif (loc + n - 1 < buf_size(my_buf)) return @buf_list[my_buf][loc, n] # String. else # should do loop insted of (tail) recursive call... res = @buf_list[my_buf][loc, BufSize] size_added = buf_size(my_buf) - loc if size_added > 0 idx += size_added n -= size_added ret = self[idx, n] if ret res << ret end end return res end end alias get [] # drop a string from the stream. # returns dropped size. at EOF, dropped size might not equals to arg n. # Once you drop the head of the stream, access to the dropped part via [] # or get returns nil. def drop(n) if is_eos? return 0 end size_dropped = 0 while (n > 0) if !@is_eos or (@cur_buf != @buf_tail_idx) if (@offset + n < buf_size(@cur_buf)) size_dropped += n @offset += n n = 0 else size = buf_size(@cur_buf) - @offset size_dropped += size n -= size @offset = 0 unless rel_buf unless add_buf break end @cur_buf = @buf_tail_idx end end end end size_dropped end def is_eos? return idx_is_eos?(0) end # WARN: Do not instantiate this class directly. Define your own class # which derives this class and define 'read' instance method. def initialize @buf_list = [] @cur_buf = @buf_tail_idx = -1 @offset = 0 @is_eos = false add_buf @cur_buf = @buf_tail_idx end protected def terminate while (rel_buf); end end # protected method 'read' must be defined in derived classes. # CAUTION: Returning a string which size is not equal to 'size' means # EnfOfStream. When it is not at EOS, you must block the callee, try to # read and return the sized string. def read(size) # raise EOFError raise NotImplementedError.new('Method read must be defined in a derived class.') end private def buf_size(idx) @buf_list[idx].size end def add_buf if @is_eos return false end begin str_read = read(BufSize) rescue EOFError str_read = nil rescue terminate raise end if str_read.nil? @is_eos = true @buf_list.push('') @buf_tail_idx += 1 false else @buf_list.push(str_read) @buf_tail_idx += 1 true end end def rel_buf if (@cur_buf < 0) return false end @buf_list[@cur_buf] = nil if (@cur_buf == @buf_tail_idx) @cur_buf = -1 return false else @cur_buf += 1 return true end end def idx_is_eos?(idx) (@is_eos and ((@cur_buf < 0) or (@cur_buf == @buf_tail_idx))) end BufSize = 1024 * 8 end # Buffered IO. # # EXAMPLE # # File 'bigdata' could be a giga-byte size one! # buf = CSV::IOBuf.new(File.open('bigdata', 'rb')) # CSV::Reader.new(buf).each do |row| # p row # break if row[0].data == 'admin' # end # class IOBuf < StreamBuf def initialize(s) @s = s super() end def close terminate end private def read(size) @s.read(size) end def terminate super() end end end