Returns a JSON
string representing self
:
require 'json/add/datetime' puts DateTime.now.to_json
Output:
{"json_class":"DateTime","y":2023,"m":11,"d":21,"sg":2299161.0}
Returns self.
Returns a Date
object which denotes self.
Returns a DateTime
object which denotes self.
See as_json
.
Returns a JSON
string representing self
:
require 'json/add/time' puts Time.now.to_json
Output:
{"json_class":"Time","s":1700931678,"n":980650786}
Returns a hash of the name/value pairs, to use in pattern matching. Possible keys are: :year
, :month
, :day
, :yday
, :wday
, :hour
, :min
, :sec
, :subsec
, :dst
, :zone
.
Possible usages:
t = Time.utc(2022, 10, 5, 21, 25, 30) if t in wday: 3, day: ..7 # uses deconstruct_keys underneath puts "first Wednesday of the month" end #=> prints "first Wednesday of the month" case t in year: ...2022 puts "too old" in month: ..9 puts "quarter 1-3" in wday: 1..5, month: puts "working day in month #{month}" end #=> prints "working day in month 10"
Note that deconstruction by pattern can also be combined with class check:
if t in Time(wday: 3, day: ..7) puts "first Wednesday of the month" end
Set
the cursor position at column
in the same line of the current position.
You must require ‘io/console’ to use this method.
Erases the screen at the cursor corresponding to mode
. mode
may be either: 0: after cursor 1: before and cursor 2: entire screen
You must require ‘io/console’ to use this method.
Scrolls the entire scrolls forward n
lines.
You must require ‘io/console’ to use this method.
Clears the entire screen and moves the cursor top-left corner.
You must require ‘io/console’ to use this method.
Waits until IO
is readable and returns a truthy value, or a falsy value when times out. Returns a truthy value immediately when buffered data is available.
You must require ‘io/wait’ to use this method.
Waits until IO
is priority and returns a truthy value or a falsy value when times out. Priority data is sent and received using the Socket::MSG_OOB flag and is typically limited to streams.
You must require ‘io/wait’ to use this method.
Synonym for IO.new
.
Returns self
.
Closes the stream for reading if open for reading; returns nil
. See Open and Closed Streams.
If the stream was opened by IO.popen
and is also closed for writing, sets global variable $?
(child exit status).
Example:
IO.popen('ruby', 'r+') do |pipe| puts pipe.closed? pipe.close_write puts pipe.closed? pipe.close_read puts $? puts pipe.closed? end
Output:
false false pid 14748 exit 0 true
Related: IO#close
, IO#close_write
, IO#closed?
.
Returns the path associated with the IO
, or nil
if there is no path associated with the IO
. It is not guaranteed that the path exists on the filesystem.
$stdin.path # => "<STDIN>" File.open("testfile") {|f| f.path} # => "testfile"
Reads at most maxlen bytes from ios using the read(2) system call after O_NONBLOCK is set for the underlying file descriptor.
If the optional outbuf argument is present, it must reference a String
, which will receive the data. The outbuf will contain only the received data after the method call even if it is not empty at the beginning.
read_nonblock
just calls the read(2) system call. It causes all errors the read(2) system call causes: Errno::EWOULDBLOCK, Errno::EINTR, etc. The caller should care such errors.
If the exception is Errno::EWOULDBLOCK or Errno::EAGAIN, it is extended by IO::WaitReadable
. So IO::WaitReadable
can be used to rescue the exceptions for retrying read_nonblock.
read_nonblock
causes EOFError
on EOF.
On some platforms, such as Windows, non-blocking mode is not supported on IO
objects other than sockets. In such cases, Errno::EBADF will be raised.
If the read byte buffer is not empty, read_nonblock
reads from the buffer like readpartial. In this case, the read(2) system call is not called.
When read_nonblock
raises an exception kind of IO::WaitReadable
, read_nonblock
should not be called until io is readable for avoiding busy loop. This can be done as follows.
# emulates blocking read (readpartial). begin result = io.read_nonblock(maxlen) rescue IO::WaitReadable IO.select([io]) retry end
Although IO#read_nonblock
doesn’t raise IO::WaitWritable
. OpenSSL::Buffering#read_nonblock
can raise IO::WaitWritable
. If IO
and SSL should be used polymorphically, IO::WaitWritable
should be rescued too. See the document of OpenSSL::Buffering#read_nonblock
for sample code.
Note that this method is identical to readpartial except the non-blocking flag is set.
By specifying a keyword argument exception to false
, you can indicate that read_nonblock
should not raise an IO::WaitReadable
exception, but return the symbol :wait_readable
instead. At EOF, it will return nil instead of raising EOFError
.
Returns a JSON
string representing self
:
require 'json/add/bigdecimal' puts BigDecimal(2).to_json puts BigDecimal(2.0, 4).to_json puts BigDecimal(Complex(2, 0)).to_json
Output:
{"json_class":"BigDecimal","b":"27:0.2e1"} {"json_class":"BigDecimal","b":"36:0.2e1"} {"json_class":"BigDecimal","b":"27:0.2e1"}