Ruby

class IO

#

# call-seq:

# IO.write(name, string, [offset] ) => fixnum

# IO.write(name, string, [offset], open_args ) => fixnum

#

# Opens the file, optionally seeks to the given <i>offset</i>, writes

# <i>string</i>, then returns the length written.

# <code>write</code> ensures the file is closed before returning.

# If <i>offset</i> is not given, the file is truncated. Otherwise,

# it is not truncated.

#

# If the last argument is a hash, it specifies option for internal

# open(). The key would be the following. open_args: is exclusive

# to others.

#

# encoding: string or encoding

#

# specifies encoding of the read string. encoding will be ignored

# if length is specified.

#

# mode: string

#

# specifies mode argument for open(). it should start with "w" or "a" or "r+"

# otherwise it would cause error.

#

# perm: fixnum

#

# specifies perm argument for open().

#

# open_args: array of strings

#

# specifies arguments for open() as an array.

#

# IO.write("testfile", "0123456789") #=> "0123456789"

# IO.write("testfile", "0123456789", 20) #=> "This is line one\nThi0123456789two\nThis is line three\nAnd so on...\n"

#

def self.write name, string, offset=nil, open_args = nil

# 3rd param could be offset or open_args

if !open_args && offset.is_a?(Hash)

open_args = offset

offset = nil

end

if offset

open_args ||= (File::RDWR|File::CREAT)

else

open_args ||= 'w'

end

open(name, open_args || 'w') do |f|

if offset

f.seek offset

end

f.write string

end

end

# call-seq:

# IO.binwrite(name, string, [offset] ) => fixnum

#

# Opens the file, optionally seeks to the given <i>offset</i>, write

# <i>string</i> then returns the length written.

# <code>binwrite</code> ensures the file is closed before returning.

# The open mode would be "wb:ASCII-8BIT".

# If <i>offset</i> is not given, the file is truncated. Otherwise,

# it is not truncated.

#

# IO.binwrite("testfile", "0123456789") #=> "0123456789"

# IO.binwrite("testfile", "0123456789", 20) #=> "This is line one\nThi0123456789two\nThis is line three\nAnd so on...\n"

#

def self.binwrite name, string, offset = nil

open_args = offset ? (File::RDWR|File::CREAT|File::BINARY) : 'wb'

open(name, open_args) do |f|

if offset

f.seek offset

end

f.write string

end

end

end

def test_s_write

t = Tempfile.new("foo")

path = t.path

t.close(false)

File.write(path, "foo\nbar\nbaz")

assert_equal("foo\nbar\nbaz", File.read(path))

File.write(path, "FOO", 0)

assert_equal("FOO\nbar\nbaz", File.read(path))

File.write(path, "BAR")

assert_equal("BAR", File.read(path))

File.write(path, "\u{3042}", mode: "w", encoding: "EUC-JP")

assert_equal("\u{3042}".encode("EUC-JP"), File.read(path, encoding: "EUC-JP"))

File.delete t

assert_equal(6, File.write(path,'string',2))

File.delete t

assert_raise(Errno::EINVAL) { File.write('/tmp/nonexisting','string',-2) }

assert_equal(6, File.write(path, 'string'))

assert_equal(3, File.write(path, 'sub', 1))

assert_equal("ssubng", File.read(path))

t.unlink

end

def test_s_binwrite

t = Tempfile.new("foo")

path = t.path

t.close(false)

File.binwrite(path, "foo\nbar\nbaz")

assert_equal("foo\nbar\nbaz", File.read(path))

File.binwrite(path, "FOO", 0)

assert_equal("FOO\nbar\nbaz", File.read(path))

File.binwrite(path, "BAR")

assert_equal("BAR", File.read(path))

File.binwrite(path, "\u{3042}")

assert_equal("\u{3042}".force_encoding("ASCII-8BIT"), File.binread(path))

File.delete t

assert_equal(6, File.binwrite(path,'string',2))

File.delete t

assert_equal(6, File.binwrite(path, 'string'))

assert_equal(3, File.binwrite(path, 'sub', 1))

assert_equal("ssubng", File.binread(path))

assert_equal(6, File.size(path))

assert_raise(Errno::EINVAL) { File.binwrite('/tmp/nonexisting','string',-2) }

assert_raise(TypeError) { File.binwrite(path, "string", mode: "w", encoding: "EUC-JP") }

t.unlink

end