stdlib_libraries/socket_reading_lengths.rb

tests/_examples/stdlib_libraries/socket_reading_lengths.rb in the metorex repository.

# A socket read of a length waits for that many bytes or for the other end
# to finish, and a read with no length waits for the end. `eof?` waits for
# either and leaves what arrived to be read.
require "socket"

near, far = UNIXSocket.pair
far.write("abc")
waiting = Thread.new { near.read(10) }
Thread.pass until waiting.stop?
p(waiting.status)
far.write("defghijklm")
p(waiting.value)
far.close
p(near.read)
p(near.read(5))

server = TCPServer.new("127.0.0.1", 0)
client = TCPSocket.new("127.0.0.1", server.addr[1])
peer = server.accept
peer.write("12")
p(client.eof?)
counted = Thread.new { client.read(4) }
Thread.pass until counted.stop?
peer.write("34")
p(counted.value)
peer.write("line one\r\n\r\nrest")
p(client.gets("\r\n\r\n"))
peer.close
p(client.read)
p(client.eof?)
p(client.read(3))

left, right = UNIXSocket.pair
left.write("foo")
p(left.close_write)
p(right.read(4))

Output:

"sleep"
"abcdefghij"
"klm"
nil
false
"1234"
"line one\r\n\r\n"
"rest"
true
nil
nil
"foo"