class IO::FileDescriptor

Overview

An IO over a file descriptor.

Included Modules

Direct Known Subclasses

Defined in:

io/console.cr
io/file_descriptor.cr

Constructors

Class Method Summary

Instance Method Summary

Macro Summary

Instance methods inherited from module IO::Buffered

buffer_size buffer_size, buffer_size=(value) buffer_size=, close : Nil close, flush flush, flush_on_newline=(flush_on_newline) flush_on_newline=, flush_on_newline? flush_on_newline?, peek : Bytes? peek, read(slice : Bytes) read, read_buffering=(read_buffering) read_buffering=, read_buffering? read_buffering?, rewind rewind, sync=(sync) sync=, sync? sync?, unbuffered_close unbuffered_close, unbuffered_flush unbuffered_flush, unbuffered_read(slice : Bytes) unbuffered_read, unbuffered_rewind unbuffered_rewind, unbuffered_write(slice : Bytes) unbuffered_write, write(slice : Bytes) : Nil write

Instance methods inherited from module Crystal::System::FileDescriptor

file_descriptor_close file_descriptor_close

Class methods inherited from module Crystal::System::FileDescriptor

fcntl(fd, cmd, arg = 0) fcntl, from_stdio(fd) from_stdio, pipe(read_blocking, write_blocking) pipe, pread(fd, buffer, offset) pread

Instance methods inherited from module IO::Evented

evented_close evented_close, evented_read(slice : Bytes, errno_msg : String, &) : Int32 evented_read, evented_reopen evented_reopen, evented_send(slice : Bytes, errno_msg : String, &) : Int32 evented_send, evented_write(slice : Bytes, errno_msg : String, &) : Nil evented_write, read_timeout : Time::Span? read_timeout, read_timeout=(read_timeout : Number) : Number
read_timeout=(timeout : Time::Span?) : Time::Span?
read_timeout=
, write_timeout : Time::Span? write_timeout, write_timeout=(write_timeout : Number) : Number
write_timeout=(timeout : Time::Span?) : Time::Span?
write_timeout=

Instance methods inherited from class IO

<<(obj) : self <<, close close, closed? closed?, each_byte(&) : Nil
each_byte
each_byte
, each_char(&) : Nil
each_char
each_char
, each_line(*args, **options, &block : String -> ) : Nil
each_line(*args, **options)
each_line
, encoding : String encoding, flush flush, gets(limit : Int, chomp = false) : String?
gets(delimiter : Char, limit : Int, chomp = false) : String?
gets(delimiter : Char, chomp = false) : String?
gets(delimiter : String, chomp = false) : String?
gets(chomp = true) : String?
gets
, gets_to_end : String gets_to_end, peek : Bytes? peek, pos pos, pos=(value) pos=, print(obj) : Nil
print(*objects : _) : Nil
print
, printf(format_string, args : Array | Tuple) : Nil
printf(format_string, *args) : Nil
printf
, puts(string : String) : Nil
puts(obj) : Nil
puts : Nil
puts(*objects : _) : Nil
puts
, read(slice : Bytes) read, read_at(offset, bytesize, & : IO -> ) 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) : Int64
copy(src, dst) : Int64
copy
, pipe(read_blocking = false, write_blocking = false) : Tuple(IO::FileDescriptor, IO::FileDescriptor)
pipe(read_blocking = false, write_blocking = false, &)
pipe
, same_content?(stream1 : IO, stream2 : IO) same_content?

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

! : Bool !, !=(other) !=, !~(other) !~, ==(other) ==, ===(other : JSON::Any)
===(other : YAML::Any)
===(other)
===
, =~(other) =~, as(type : Class) as, as?(type : Class) as?, class class, dup dup, hash(hasher)
hash
hash
, in?(collection) : Bool
in?(*values : Object) : Bool
in?
, inspect(io : IO) : Nil
inspect : String
inspect
, is_a?(type : Class) : Bool is_a?, itself itself, nil? : Bool nil?, not_nil! not_nil!, pretty_inspect(width = 79, newline = "\n", indent = 0) : String pretty_inspect, pretty_print(pp : PrettyPrint) : Nil pretty_print, responds_to?(name : Symbol) : Bool responds_to?, tap(&) 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(io : IO) : Nil
to_s : String
to_s
, to_yaml(io : IO)
to_yaml
to_yaml
, try(&) try, unsafe_as(type : T.class) forall T unsafe_as

Class methods inherited from class Object

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

Constructor Detail

def self.new(fd, blocking = nil) #

[View source]

Class Method Detail

def self.fcntl(fd, cmd, arg = 0) #

[View source]

Instance Method Detail

def blocking #

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def blocking=(value) #

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def close_on_exec=(value : Bool) #

[View source]
def close_on_exec? #

[View source]
def closed? : Bool #
Description copied from class IO

Returns true if this IO is closed.

IO defines returns false, but including types may override.


[View source]
def cooked(&) #

Enables character processing for the duration of the given block. The so called cooked mode is the standard behavior of a terminal, doing line wise editing by the terminal and only sending the input to the program on a newline. Only call this when this IO is a TTY, such as a not redirected stdin.


[View source]
def cooked! #

Enables character processing for this IO. The so called cooked mode is the standard behavior of a terminal, doing line wise editing by the terminal and only sending the input to the program on a newline. Only call this when this IO is a TTY, such as a not redirected stdin.


[View source]
def fcntl(cmd, arg = 0) #

[View source]
def fd #

The raw file-descriptor. It is defined to be an Int, but its size is platform-specific.


[View source]
def finalize #

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def flock_exclusive(blocking = true, &) #

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def flock_exclusive(blocking = true) #

Places an exclusive advisory lock. Only one process may hold an exclusive lock for a given file descriptor at a given time. IO::Error is raised if blocking is set to false and any existing lock is set.


[View source]
def flock_shared(blocking = true, &) #

[View source]
def flock_shared(blocking = true) #

Places a shared advisory lock. More than one process may hold a shared lock for a given file descriptor at a given time. IO::Error is raised if blocking is set to false and an existing exclusive lock is set.


[View source]
def flock_unlock #

Removes an existing advisory lock held by this process.


[View source]
def fsync(flush_metadata = true) : Nil #

Flushes all data written to this File Descriptor to the disk device so that all changed information can be retrieved even if the system crashes or is rebooted. The call blocks until the device reports that the transfer has completed. To reduce disk activity the flush_metadata parameter can be set to false, then the syscall fdatasync will be used and only data required for subsequent data retrieval is flushed. Metadata such as modified time and access time is not written.

NOTE Metadata is flushed even when flush_metadata is false on Windows and DragonFly BSD.


[View source]
def info #

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def inspect(io : IO) : Nil #
Description copied from class Reference

Appends a String representation of this object which includes its class name, its object address and the values of all instance variables.

class Person
  def initialize(@name : String, @age : Int32)
  end
end

Person.new("John", 32).inspect # => #<Person:0x10fd31f20 @name="John", @age=32>

[View source]
def noecho(&) #

Turns off character echoing for the duration of the given block. This will prevent displaying back to the user what they enter on the terminal. Only call this when this IO is a TTY, such as a not redirected stdin.

print "Enter password: "
password = STDIN.noecho &.gets.try &.chomp
puts

[View source]
def noecho! #

Turns off character echoing for this IO. This will prevent displaying back to the user what they enter on the terminal. Only call this when this IO is a TTY, such as a not redirected stdin.


[View source]
def pos #

Returns the current position (in bytes) in this IO.

File.write("testfile", "hello")

file = File.new("testfile")
file.pos     # => 0
file.gets(2) # => "he"
file.pos     # => 2

[View source]
def pos=(value) #

Sets the current position (in bytes) in this IO.

File.write("testfile", "hello")

file = File.new("testfile")
file.pos = 3
file.gets_to_end # => "lo"

[View source]
def pretty_print(pp) #

[View source]
def raw(&) #

Enables raw mode for the duration of the given block. In raw mode every keypress is directly sent to the program, no interpretation is done by the terminal. Only call this when this IO is a TTY, such as a not redirected stdin.


[View source]
def raw! #

Enables raw mode for this IO. In raw mode every keypress is directly sent to the program, no interpretation is done by the terminal. Only call this when this IO is a TTY, such as a not redirected stdin.


[View source]
def reopen(other : IO::FileDescriptor) #

[View source]
def seek(offset, whence : Seek = Seek::Set) #

Seeks to a given offset (in bytes) according to the whence argument. Returns self.

File.write("testfile", "abc")

file = File.new("testfile")
file.gets(3) # => "abc"
file.seek(1, IO::Seek::Set)
file.gets(2) # => "bc"
file.seek(-1, IO::Seek::Current)
file.gets(1) # => "c"

[View source]
def seek(offset, whence : Seek = Seek::Set, &) #

Same as #seek but yields to the block after seeking and eventually seeks back to the original position when the block returns.


[View source]
def tty? #
Description copied from class IO

Returns true if this IO is associated with a terminal device (tty), false otherwise.

IO returns false, but including types may override.

STDIN.tty?          # => true
IO::Memory.new.tty? # => false

[View source]

Macro Detail

macro cooked_from_tc_mode! #

[View source]
macro noecho_from_tc_mode! #

[View source]
macro raw_from_tc_mode! #

[View source]