Sets the named constant to the given object, returning that object. Creates a new constant if no constant with the given name previously existed.
Math.const_set("HIGH_SCHOOL_PI", 22.0/7.0) #=> 3.14285714285714 Math::HIGH_SCHOOL_PI - Math::PI #=> 0.00126448926734968
If sym
or str
is not a valid constant name a NameError
will be raised with a warning “wrong constant name”.
Object.const_set('foobar', 42) #=> NameError: wrong constant name foobar
Return the number of seconds the specified time zone differs from UTC.
Numeric
time zones that include minutes, such as -10:00
or +1330
will work, as will simpler hour-only time zones like -10
or +13
.
Textual time zones listed in ZoneOffset are also supported.
If the time zone does not match any of the above, zone_offset
will check if the local time zone (both with and without potential Daylight Saving Time changes being in effect) matches zone
. Specifying a value for year
will change the year used to find the local time zone.
If zone_offset
is unable to determine the offset, nil will be returned.
Try to convert obj into an IO
, using to_io
method. Returns converted IO
or nil
if obj cannot be converted for any reason.
IO.try_convert(STDOUT) #=> STDOUT IO.try_convert("STDOUT") #=> nil require 'zlib' f = open("/tmp/zz.gz") #=> #<File:/tmp/zz.gz> z = Zlib::GzipReader.open(f) #=> #<Zlib::GzipReader:0x81d8744> IO.try_convert(z) #=> #<File:/tmp/zz.gz>
Provides marshalling support for use by the Marshal
library.
Provides marshalling support for use by the Marshal
library.
Try to convert obj into a Regexp
, using to_regexp method. Returns converted regexp or nil if obj cannot be converted for any reason.
Regexp.try_convert(/re/) #=> /re/ Regexp.try_convert("re") #=> nil o = Object.new Regexp.try_convert(o) #=> nil def o.to_regexp() /foo/ end Regexp.try_convert(o) #=> /foo/
Accepts an incoming connection using accept(2) after O_NONBLOCK is set for the underlying file descriptor. It returns an array containing the accepted socket for the incoming connection, client_socket, and an Addrinfo
, client_addrinfo.
# In one script, start this first require 'socket' include Socket::Constants socket = Socket.new(AF_INET, SOCK_STREAM, 0) sockaddr = Socket.sockaddr_in(2200, 'localhost') socket.bind(sockaddr) socket.listen(5) begin # emulate blocking accept client_socket, client_addrinfo = socket.accept_nonblock rescue IO::WaitReadable, Errno::EINTR IO.select([socket]) retry end puts "The client said, '#{client_socket.readline.chomp}'" client_socket.puts "Hello from script one!" socket.close # In another script, start this second require 'socket' include Socket::Constants socket = Socket.new(AF_INET, SOCK_STREAM, 0) sockaddr = Socket.sockaddr_in(2200, 'localhost') socket.connect(sockaddr) socket.puts "Hello from script 2." puts "The server said, '#{socket.readline.chomp}'" socket.close
Refer to Socket#accept
for the exceptions that may be thrown if the call to accept_nonblock fails.
Socket#accept_nonblock
may raise any error corresponding to accept(2) failure, including Errno::EWOULDBLOCK.
If the exception is Errno::EWOULDBLOCK, Errno::EAGAIN, Errno::ECONNABORTED
or Errno::EPROTO
, it is extended by IO::WaitReadable
. So IO::WaitReadable
can be used to rescue the exceptions for retrying accept_nonblock.
By specifying a keyword argument exception to false
, you can indicate that accept_nonblock
should not raise an IO::WaitReadable
exception, but return the symbol :wait_readable
instead.
yield socket and client address for each a connection accepted via given sockets.
The arguments are a list of sockets. The individual argument should be a socket or an array of sockets.
This method yields the block sequentially. It means that the next connection is not accepted until the block returns. So concurrent mechanism, thread for example, should be used to service multiple clients at a time.
Requests a connection to be made on the given remote_sockaddr
after O_NONBLOCK is set for the underlying file descriptor. Returns 0 if successful, otherwise an exception is raised.
# +remote_sockaddr+ - the +struct+ sockaddr contained in a string or Addrinfo object
# Pull down Google's web page require 'socket' include Socket::Constants socket = Socket.new(AF_INET, SOCK_STREAM, 0) sockaddr = Socket.sockaddr_in(80, 'www.google.com') begin # emulate blocking connect socket.connect_nonblock(sockaddr) rescue IO::WaitWritable IO.select(nil, [socket]) # wait 3-way handshake completion begin socket.connect_nonblock(sockaddr) # check connection failure rescue Errno::EISCONN end end socket.write("GET / HTTP/1.0\r\n\r\n") results = socket.read
Refer to Socket#connect
for the exceptions that may be thrown if the call to connect_nonblock fails.
Socket#connect_nonblock
may raise any error corresponding to connect(2) failure, including Errno::EINPROGRESS.
If the exception is Errno::EINPROGRESS, it is extended by IO::WaitWritable
. So IO::WaitWritable
can be used to rescue the exceptions for retrying connect_nonblock.
By specifying a keyword argument exception to false
, you can indicate that connect_nonblock
should not raise an IO::WaitWritable
exception, but return the symbol :wait_writable
instead.
# Socket#connect
sendmsg_nonblock
sends a message using sendmsg(2) system call in non-blocking manner.
It is similar to BasicSocket#sendmsg
but the non-blocking flag is set before the system call and it doesn’t retry the system call.
By specifying a keyword argument exception to false
, you can indicate that sendmsg_nonblock
should not raise an IO::WaitWritable
exception, but return the symbol :wait_writable
instead.
creates a new Socket
connected to the address of local_addrinfo
.
If local_addrinfo is nil, the address of the socket is not bound.
The timeout specify the seconds for timeout. Errno::ETIMEDOUT is raised when timeout occur.
If a block is given the created socket is yielded for each address.
Returns the IP address and port number as 2-element array.
Addrinfo.tcp("127.0.0.1", 80).ip_unpack #=> ["127.0.0.1", 80] Addrinfo.tcp("::1", 80).ip_unpack #=> ["::1", 80]
Accepts an incoming connection using accept(2) after O_NONBLOCK is set for the underlying file descriptor. It returns an accepted TCPSocket
for the incoming connection.
require 'socket' serv = TCPServer.new(2202) begin # emulate blocking accept sock = serv.accept_nonblock rescue IO::WaitReadable, Errno::EINTR IO.select([serv]) retry end # sock is an accepted socket.
Refer to Socket#accept
for the exceptions that may be thrown if the call to TCPServer#accept_nonblock
fails.
TCPServer#accept_nonblock
may raise any error corresponding to accept(2) failure, including Errno::EWOULDBLOCK.
If the exception is Errno::EWOULDBLOCK, Errno::EAGAIN, Errno::ECONNABORTED
, Errno::EPROTO
, it is extended by IO::WaitReadable
. So IO::WaitReadable
can be used to rescue the exceptions for retrying accept_nonblock.
By specifying a keyword argument exception to false
, you can indicate that accept_nonblock
should not raise an IO::WaitReadable
exception, but return the symbol :wait_readable
instead.
Accepts an incoming connection using accept(2) after O_NONBLOCK is set for the underlying file descriptor. It returns an accepted UNIXSocket
for the incoming connection.
require 'socket' serv = UNIXServer.new("/tmp/sock") begin # emulate blocking accept sock = serv.accept_nonblock rescue IO::WaitReadable, Errno::EINTR IO.select([serv]) retry end # sock is an accepted socket.
Refer to Socket#accept
for the exceptions that may be thrown if the call to UNIXServer#accept_nonblock
fails.
UNIXServer#accept_nonblock
may raise any error corresponding to accept(2) failure, including Errno::EWOULDBLOCK.
If the exception is Errno::EWOULDBLOCK, Errno::EAGAIN, Errno::ECONNABORTED
or Errno::EPROTO
, it is extended by IO::WaitReadable
. So IO::WaitReadable
can be used to rescue the exceptions for retrying accept_nonblock.
By specifying a keyword argument exception to false
, you can indicate that accept_nonblock
should not raise an IO::WaitReadable
exception, but return the symbol :wait_readable
instead.
Sends io as file descriptor passing.
s1, s2 = UNIXSocket.pair s1.send_io STDOUT stdout = s2.recv_io p STDOUT.fileno #=> 1 p stdout.fileno #=> 6 stdout.puts "hello" # outputs "hello\n" to standard output.
io may be any kind of IO
object or integer file descriptor.
Duplicates a StringScanner
object.
Scans the string until the pattern
is matched. Advances the scan pointer if advance_pointer_p
, otherwise not. Returns the matched string if return_string_p
is true, otherwise returns the number of bytes advanced. This method does affect the match register.
Returns the size of arguments of the method.
tobj = WIN32OLE_TYPE.new('Microsoft Excel 9.0 Object Library', 'Workbook') method = WIN32OLE_METHOD.new(tobj, 'SaveAs') puts method.size_params # => 11
Try to convert obj into a hash, using to_hash
method. Returns converted hash or nil if obj cannot be converted for any reason.
Hash.try_convert({1=>2}) # => {1=>2} Hash.try_convert("1=>2") # => nil
Returns true
if unconverted_fields() to parsed results. See CSV::new
for details.
Returns true
if headers will be returned as a row of results. See CSV::new
for details.
Returns true
if headers are written in output. See CSV::new
for details.
Stores header row settings and loads header converters, if needed.
Processes fields
with @converters
, or @header_converters
if headers
is passed as true
, returning the converted field set. Any converter that changes the field into something other than a String halts the pipeline of conversion for that field. This is primarily an efficiency shortcut.