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/Crystal 0.31

class IO::MultiWriter

Overview

An IO which writes to a number of underlying writer IOs.

io1 = IO::Memory.new
io2 = IO::Memory.new
writer = IO::MultiWriter.new(io1, io2)
writer.puts "foo bar"
io1.to_s # => "foo bar\n"
io2.to_s # => "foo bar\n"

Defined in:

io/multi_writer.cr

Constructors

Instance Method Summary

Instance methods inherited from class IO

<self <<, close close, closed? closed?, each_byte(&block) : Nil
each_byte each_byte
, each_char(&block) : Nil
each_char each_char
, each_line(*args, **options, &block : String -> ) : Nil
each_line(*args, **options) each_line
, encoding : String encoding, flush flush, gets(delimiter : Char, limit : Int, chomp = false) : String?
gets(delimiter : Char, chomp = false) : String?
gets(chomp = true) : String?
gets(limit : Int, chomp = false) : String?
gets(delimiter : String, chomp = false) : String? gets
, gets_to_end : String gets_to_end, peek : Bytes? peek, pos pos, pos=(value) pos=, print(*objects : UNDERSCORE) : Nil
print(obj) : Nil print
, printf(format_string, *args) : Nil
printf(format_string, args : Array | Tuple) : Nil printf
, puts(*objects : UNDERSCORE) : Nil
puts : Nil
puts(obj) : Nil
puts(string : String) : Nil puts
, read(slice : Bytes) read, read_at(offset, bytesize, &block) read_at, read_byte : UInt8? read_byte, read_bytes(type, format : IO::ByteFormat = IO::ByteFormat::SystemEndian) read_bytes, read_char : Char? read_char, read_fully(slice : Bytes) read_fully, read_fully?(slice : Bytes) read_fully?, read_line(*args, **options) : String read_line, read_string(bytesize : Int) : String read_string, read_utf8(slice : Bytes) read_utf8, read_utf8_byte read_utf8_byte, rewind rewind, seek(offset, whence : Seek = Seek::Set) seek, set_encoding(encoding : String, invalid : Symbol? = nil) set_encoding, skip(bytes_count : Int) : Nil skip, skip_to_end : Nil skip_to_end, tell tell, tty? : Bool tty?, write(slice : Bytes) : Nil write, write_byte(byte : UInt8) write_byte, write_bytes(object, format : IO::ByteFormat = IO::ByteFormat::SystemEndian) write_bytes, write_utf8(slice : Bytes) write_utf8

Class methods inherited from class IO

copy(src, dst, limit : Int) : UInt64
copy(src, dst) : UInt64 copy
, pipe(read_blocking = false, write_blocking = false) : Tuple(IO::FileDescriptor, IO::FileDescriptor)
pipe(read_blocking = false, write_blocking = false, &block) pipe

Instance methods inherited from class Reference

==(other : self)
==(other : JSON::Any)
==(other : YAML::Any)
==(other) ==
, dup dup, hash(hasher) hash, inspect(io : IO) : Nil inspect, object_id : UInt64 object_id, pretty_print(pp) : Nil pretty_print, same?(other : Reference)
same?(other : Nil) same?
, to_s(io : IO) : Nil to_s

Constructor methods inherited from class Reference

new new

Instance methods inherited from class Object

!=(other) !=, !~(other) !~, ==(other) ==, ===(other : JSON::Any)
===(other : YAML::Any)
===(other) ===
, =~(other) =~, class class, dup dup, hash(hasher)
hash hash
, inspect(io : IO) : Nil
inspect : String inspect
, itself itself, not_nil! not_nil!, pretty_inspect(width = 79, newline = "\n", indent = 0) : String pretty_inspect, pretty_print(pp : PrettyPrint) : Nil pretty_print, tap(&block) tap, to_json(io : IO)
to_json to_json
, to_pretty_json(indent : String = " ")
to_pretty_json(io : IO, indent : String = " ") to_pretty_json
, to_s : String
to_s(io : IO) : Nil to_s
, to_yaml(io : IO)
to_yaml to_yaml
, try(&block) try, unsafe_as(type : T.class) forall T unsafe_as

Constructor methods inherited from class Object

from_json(string_or_io, root : String) : self
from_json(string_or_io) : self from_json
, from_yaml(string_or_io : String | IO) : self from_yaml

Constructor Detail

def self.new(writers : Array(IO), sync_close = false)Source

Creates a new IO::MultiWriter which writes to writers. If sync_close is set, calling #close calls #close on all underlying writers.

def self.new(*writers : IO, sync_close = false)Source

Creates a new IO::MultiWriter which writes to writers. If sync_close is set, calling #close calls #close on all underlying writers.

Instance Method Detail

def closeSource

Description copied from class IO

Closes this IO.

IO defines this is a no-op method, but including types may override.

def closed? : BoolSource

Description copied from class IO

Returns true if this IO is closed.

IO defines returns false, but including types may override.

def flushSource

Description copied from class IO

Flushes buffered data, if any.

IO defines this is a no-op method, but including types may override.

def read(slice : Bytes)Source

Description copied from class IO

Reads at most slice.size bytes from this IO into slice. Returns the number of bytes read, which is 0 if and only if there is no more data to read (so checking for 0 is the way to detect end of file).

io = IO::Memory.new "hello"
slice = Bytes.new(4)
io.read(slice) # => 4
slice          # => Bytes[104, 101, 108, 108]
io.read(slice) # => 1
slice          # => Bytes[111, 101, 108, 108]
io.read(slice) # => 0

def sync_close=(sync_close)Source

If #sync_close? is true, closing this IO will close all of the underlying IOs.

def sync_close? : BoolSource

If #sync_close? is true, closing this IO will close all of the underlying IOs.

def write(slice : Bytes) : NilSource

Description copied from class IO

Writes the contents of slice into this IO.

io = IO::Memory.new
slice = Bytes.new(4) { |i| ('a'.ord + i).to_u8 }
io.write(slice)
io.to_s # => "abcd"

© 2012–2019 Manas Technology Solutions.
Licensed under the Apache License, Version 2.0.
https://crystal-lang.org/api/0.31.1/IO/MultiWriter.html