Net::SSH::Multi::Channel

Net::SSH::Multi::Channel encapsulates a collection of Net::SSH::Connection::Channel instances from multiple different connections. It allows for operations to be performed on all contained channels, simultaneously, using an interface mostly identical to Net::SSH::Connection::Channel itself.

You typically obtain a Net::SSH::Multi::Channel instance via Net::SSH::Multi::Session#open_channel or Net::SSH::Multi::Session#exec, though there is nothing stopping you from instantiating one yourself with a handful of Net::SSH::Connection::Channel objects (though they should be associated with connections managed by a Net::SSH::Multi::Session object for consistent behavior).

channel = session.open_channel do |ch|
  # ...
end
channel.wait

Methods

Public Class

new

Public Instance

[]
[]=
active?
channels
close
connection
each
eof!
exec
on_close
on_data
on_eof
on_extended_data
on_open_failed
on_process
on_request
properties
request_pty
send_data
wait

Included modules

Enumerable

Attributes

channels	[R]	The collection of Net::SSH::Connection::Channel instances that this multi-channel aggregates.
connection	[R]	The Net::SSH::Multi::Session instance that controls this channel collection.
properties	[R]	A Hash of custom properties that may be set and queried on this object.

Public Class methods

new (connection, channels)

Instantiate a new Net::SSH::Multi::Channel instance, controlled by the given connection (a Net::SSH::Multi::Session object) and wrapping the given channels (Net::SSH::Connection::Channel instances).

You will typically never call this directly; rather, you'll get your multi-channel references via Net::SSH::Multi::Session#open_channel and friends.

# File lib/net/ssh/multi/channel.rb, line 38
def initialize(connection, channels)
  @connection = connection
  @channels = channels
  @properties = {}
end

Public Instance methods

[] (key)

Retrieve the property (see properties) with the given key.

host = channel[:host]

# File lib/net/ssh/multi/channel.rb, line 53
def [](key)
  @properties[key]
end

[]= (key, value)

Set the property (see properties) with the given key to the given value.

channel[:visited] = true

# File lib/net/ssh/multi/channel.rb, line 61
def []=(key, value)
  @properties[key] = value
end

active? ()

Returns true as long as any of the component channels are active.

connection.loop { channel.active? }

# File lib/net/ssh/multi/channel.rb, line 112
def active?
  channels.any? { |channel| channel.active? }
end

close ()

Closes all component channels.

# File lib/net/ssh/multi/channel.rb, line 127
def close
  channels.each { |channel| channel.close }
  self
end

each ()

Iterate over each component channel object, yielding each in order to the associated block.

# File lib/net/ssh/multi/channel.rb, line 46
def each
  @channels.each { |channel| yield channel }
end

eof! ()

Tells the remote process for each component channel not to expect any further data from this end of the channel.

# File lib/net/ssh/multi/channel.rb, line 134
def eof!
  channels.each { |channel| channel.eof! }
  self
end

exec (command, &block)

Perform an exec command on all component channels. The block, if given, is passed to each component channel, so it will (potentially) be invoked once for every channel in the collection. The block will receive two parameters: the specific channel object being operated on, and a boolean indicating whether the exec succeeded or not.

channel.exec "ls -l" do |ch, success|
  # ...
end

See the documentation in Net::SSH for Net::SSH::Connection::Channel#exec for more information on how to work with the callback.

# File lib/net/ssh/multi/channel.rb, line 77
def exec(command, &block)
  channels.each { |channel| channel.exec(command, &block) }
  self
end

on_close (&block)

Registers a callback on all component channels, to be invoked when the remote server terminates the channel. The callback will be invoked with one argument: the specific channel object being closed.

channel.on_close do |ch|
  # ...
end

# File lib/net/ssh/multi/channel.rb, line 185
def on_close(&block)
  channels.each { |channel| channel.on_close(&block) }
  self
end

on_data (&block)

Registers a callback on all component channels, to be invoked when the remote process emits data (usually on its stdout stream). The block will be invoked with two arguments: the specific channel object, and the data that was received.

channel.on_data do |ch, data|
  puts "got data: #{data}"
end

# File lib/net/ssh/multi/channel.rb, line 147
def on_data(&block)
  channels.each { |channel| channel.on_data(&block) }
  self
end

on_eof (&block)

Registers a callback on all component channels, to be invoked when the remote server has no further data to send. The callback will be invoked with one argument: the specific channel object being marked EOF.

channel.on_eof do |ch|
  # ...
end

# File lib/net/ssh/multi/channel.rb, line 197
def on_eof(&block)
  channels.each { |channel| channel.on_eof(&block) }
  self
end

on_extended_data (&block)

Registers a callback on all component channels, to be invoked when the remote process emits "extended" data (typically on its stderr stream). The block will be invoked with three arguments: the specific channel object, an integer describing the data type (usually a 1 for stderr) and the data that was received.

channel.on_extended_data do |ch, type, data|
  puts "got extended data: #{data}"
end

# File lib/net/ssh/multi/channel.rb, line 161
def on_extended_data(&block)
  channels.each { |channel| channel.on_extended_data(&block) }
  self
end

on_open_failed (&block)

Registers a callback on all component channels, to be invoked when the remote server is unable to open the channel. The callback will be invoked with three arguments: the channel object that couldn't be opened, a description of the error (as a string), and an integer code representing the error.

channel.on_open_failed do |ch, description, code|
  # ...
end

# File lib/net/ssh/multi/channel.rb, line 211
def on_open_failed(&block)
  channels.each { |channel| channel.on_open_failed(&block) }
  self
end

on_process (&block)

Registers a callback on all component channels, to be invoked during the idle portion of the connection event loop. The callback will be invoked with one argument: the specific channel object being processed.

channel.on_process do |ch|
  # ...
end

# File lib/net/ssh/multi/channel.rb, line 173
def on_process(&block)
  channels.each { |channel| channel.on_process(&block) }
  self
end

on_request (type, &block)

Registers a callback on all component channels, to be invoked when the remote server sends a channel request of the given type. The callback will be invoked with two arguments: the specific channel object receiving the request, and a Net::SSH::Buffer instance containing the request-specific data.

channel.on_request("exit-status") do |ch, data|
  puts "exited with #{data.read_long}"
end

# File lib/net/ssh/multi/channel.rb, line 225
def on_request(type, &block)
  channels.each { |channel| channel.on_request(type, &block) }
  self
end

request_pty (opts={}, &block)

Perform a request_pty command on all component channels. The block, if given, is passed to each component channel, so it will (potentially) be invoked once for every channel in the collection. The block will receive two parameters: the specific channel object being operated on, and a boolean indicating whether the pty request succeeded or not.

channel.request_pty do |ch, success|
  # ...
end

See the documentation in Net::SSH for Net::SSH::Connection::Channel#request_pty for more information on how to work with the callback.

# File lib/net/ssh/multi/channel.rb, line 95
def request_pty(opts={}, &block)
  channels.each { |channel| channel.request_pty(opts, &block) }
  self
end

send_data (data)

Send the given data to each component channel. It will be sent to the remote process, typically being received on the process' stdin stream.

channel.send_data "password\n"

# File lib/net/ssh/multi/channel.rb, line 104
def send_data(data)
  channels.each { |channel| channel.send_data(data) }
  self
end

wait ()

Runs the connection's event loop until the channel is no longer active (see active?).

channel.exec "something"
channel.wait

# File lib/net/ssh/multi/channel.rb, line 121
def wait
  connection.loop { active? }
  self
end