class IO::FileDescriptor
Overview
An IO
over a file descriptor.
Included Modules
- Crystal::System::FileDescriptor
- IO::Buffered
Direct Known Subclasses
Defined in:
io/console.crio/file_descriptor.cr
Constructors
Class Method Summary
Instance Method Summary
- #blocking
- #blocking=(value)
- #close_on_exec=(value : Bool)
- #close_on_exec? : Bool
-
#close_on_finalize=(close_on_finalize : Bool)
Whether or not to close the file descriptor when this object is finalized.
-
#close_on_finalize? : Bool
Whether or not to close the file descriptor when this object is finalized.
-
#closed? : Bool
Returns
true
if thisIO
is closed. -
#cooked(& : self -> _)
Yields
self
to the given block, enables character processing for the duration of the block, and returns the block's value. -
#cooked! : Nil
Enables character processing on this
IO
. -
#echo(& : self -> _)
Yields
self
to the given block, enables character echoing for the duration of the block, and returns the block's value. -
#echo! : Nil
Enables character echoing on this
IO
. - #fcntl(cmd, arg = 0)
-
#fd : Int
The raw file-descriptor.
- #finalize
- #flock_exclusive(blocking = true, &)
-
#flock_exclusive(blocking = true) : Nil
Places an exclusive advisory lock.
- #flock_shared(blocking = true, &)
-
#flock_shared(blocking = true) : Nil
Places a shared advisory lock.
-
#flock_unlock : Nil
Removes an existing advisory lock held by this process.
-
#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.
-
#info : File::Info
Returns a
File::Info
object for this file descriptor, or raisesIO::Error
in case of an error. -
#inspect(io : IO) : Nil
Appends a String representation of this object which includes its class name, its object address and the values of all instance variables.
-
#noecho(& : self -> _)
Yields
self
to the given block, disables character echoing for the duration of the block, and returns the block's value. -
#noecho! : Nil
Disables character echoing on this
IO
. -
#pos=(value)
Sets the current position (in bytes) in this
IO
. - #pretty_print(pp)
-
#raw(& : self -> _)
Yields
self
to the given block, enables raw mode for the duration of the block, and returns the block's value. -
#raw! : Nil
Enables raw mode on this
IO
. - #reopen(other : IO::FileDescriptor)
-
#seek(offset, whence : Seek = Seek::Set)
Seeks to a given offset (in bytes) according to the whence argument.
-
#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. -
#tty? : Bool
Returns
true
if thisIO
is associated with a terminal device (tty),false
otherwise.
Macro Summary
-
cooked_from_tc_mode!
DEPRECATED
-
noecho_from_tc_mode!
DEPRECATED
-
raw_from_tc_mode!
DEPRECATED
Instance methods inherited from module IO::Buffered
buffer_size : Int32
buffer_size,
buffer_size=(value)
buffer_size=,
close : Nil
close,
flush
flush,
flush_on_newline=(flush_on_newline)
flush_on_newline=,
flush_on_newline? : Bool
flush_on_newline?,
peek : Bytes
peek,
pos : Int64
pos,
read(slice : Bytes) : Int32
read,
read_buffering=(read_buffering)
read_buffering=,
read_buffering? : Bool
read_buffering?,
rewind
rewind,
sync=(sync)
sync=,
sync? : Bool
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 : Nil
file_descriptor_close
Class methods inherited from module Crystal::System::FileDescriptor
cfmakeraw(termios_p)
cfmakeraw,
fcntl(fd, cmd, arg = 0)
fcntl,
from_stdio(fd)
from_stdio,
pipe(read_blocking, write_blocking)
pipe,
pread(fd, buffer, offset)
pread,
system_info(fd)
system_info,
tcgetattr(fd)
tcgetattr,
tcsetattr(fd, optional_actions, termios_p)
tcsetattr
Instance methods inherited from module IO::Evented
evented_close : Nil
evented_close,
evented_read(slice : Bytes, errno_msg : String, &) : Int32
evented_read,
evented_reopen : Nil
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 | Nil
read_timeout,
read_timeout=(read_timeout : Number) : Numberread_timeout=(timeout : Time::Span | Nil) : Time::Span | Nil read_timeout=, write_timeout : Time::Span | Nil write_timeout, write_timeout=(write_timeout : Number) : Number
write_timeout=(timeout : Time::Span | Nil) : Time::Span | Nil write_timeout=
Instance methods inherited from class IO
<<(obj) : self
<<,
close
close,
closed? : Bool
closed?,
each_byte(&) : Nileach_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, getb_to_end : Bytes getb_to_end, gets(limit : Int, chomp = false) : String | Nil
gets(delimiter : Char, limit : Int, chomp = false) : String | Nil
gets(delimiter : Char, chomp = false) : String | Nil
gets(delimiter : String, chomp = false) : String | Nil
gets(chomp = true) : String | Nil gets, gets_to_end : String gets_to_end, peek : Bytes | Nil 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 | Nil read_byte, read_bytes(type, format : IO::ByteFormat = IO::ByteFormat::SystemEndian) read_bytes, read_char : Char | Nil read_char, read_fully(slice : Bytes) : Int32 read_fully, read_fully?(slice : Bytes) : Int32 | Nil 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 : UInt8 | Nil read_utf8_byte, rewind rewind, seek(offset, whence : Seek = Seek::Set) seek, set_encoding(encoding : String, invalid : Symbol | Nil = nil) : 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) : Nil write_byte, write_bytes(object, format : IO::ByteFormat = IO::ByteFormat::SystemEndian) : Nil write_bytes, write_string(slice : Bytes) : Nil write_string, write_utf8(slice : Bytes) : Nil write_utf8
Class methods inherited from class IO
copy(src, dst, limit : Int) : Int64copy(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) : Bool same_content?
Instance methods inherited from class Reference
==(other : self)==(other : JSON::Any)
==(other : YAML::Any)
==(other) ==, dup dup, hash(hasher) hash, initialize initialize, inspect(io : IO) : Nil inspect, object_id : UInt64 object_id, pretty_print(pp) : Nil pretty_print, same?(other : Reference) : Bool
same?(other : Nil) same?, to_s(io : IO) : Nil to_s
Constructor methods inherited from class Reference
new
new,
unsafe_construct(address : Pointer, *args, **opts) : self
unsafe_construct
Class methods inherited from class Reference
pre_initialize(address : Pointer)
pre_initialize
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 : Object) : 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!(message)
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) : Nil
to_json : String to_json, to_pretty_json(indent : String = " ") : String
to_pretty_json(io : IO, indent : String = " ") : Nil to_pretty_json, to_s(io : IO) : Nil
to_s : String to_s, to_yaml(io : IO) : Nil
to_yaml : String 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
Class Method Detail
Instance Method Detail
Whether or not to close the file descriptor when this object is finalized. Disabling this is useful in order to create an IO wrapper over a file descriptor returned from a C API that keeps ownership of the descriptor. Do note that, if the fd is closed by its owner at any point, any IO operations will then fail.
Whether or not to close the file descriptor when this object is finalized. Disabling this is useful in order to create an IO wrapper over a file descriptor returned from a C API that keeps ownership of the descriptor. Do note that, if the fd is closed by its owner at any point, any IO operations will then fail.
Returns true
if this IO
is closed.
IO
defines returns false
, but including types may override.
Yields self
to the given block, enables character processing for the
duration of the block, and returns the block's value.
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.
Enables character processing on 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.
Yields self
to the given block, enables character echoing for the
duration of the block, and returns the block's value.
This causes user input to be displayed as they are entered on the terminal.
Enables character echoing on this IO
.
This causes user input to be displayed as they are entered on the terminal.
The raw file-descriptor. It is defined to be an Int
, but its size is
platform-specific.
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.
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.
Returns a File::Info
object for this file descriptor, or raises
IO::Error
in case of an error.
Certain fields like the file size may not be updated until an explicit flush.
File.write("testfile", "abc")
file = File.new("testfile", "a")
file.info.size # => 3
file << "defgh"
file.info.size # => 3
file.flush
file.info.size # => 8
Use File.info
if the file is not open and a path to the file is available.
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>
Yields self
to the given block, disables character echoing for the
duration of the block, and returns the block's value.
This will prevent displaying back to the user what they enter on the terminal.
Raises IO::Error
if this IO
is not a terminal device.
print "Enter password: "
password = STDIN.noecho &.gets.try &.chomp
puts
Disables character echoing on this IO
.
This will prevent displaying back to the user what they enter on the terminal.
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"
Yields self
to the given block, enables raw mode for the duration of the
block, and returns the block's value.
In raw mode every keypress is directly sent to the program, no interpretation is done by the terminal. On Windows, this also enables ANSI input escape sequences.
Enables raw mode on this IO
.
In raw mode every keypress is directly sent to the program, no interpretation is done by the terminal. On Windows, this also enables ANSI input escape sequences.
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"
Same as #seek
but yields to the block after seeking and eventually seeks
back to the original position when the block returns.
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