IO

Undocumented

Undocumented

Synonym for IO.new.

Returns a new IO object (a stream) for the given integer file descriptor fd and mode string. opt may be used to specify parts of mode in a more readable fashion.

Reassociates I/O stream with the I/O stream given in another I/O or to a new stream opened on path. This may dynamically change the actual class of this stream.

Reassociates I/O stream with the I/O stream given in another I/O or to a new stream opened on path. This may dynamically change the actual class of this stream.

With no associated block, IO.open is a synonym for IO.new. If the optional code block is given, it will be passed io as an argument, and the IO object will automatically be closed when the block terminates.

Reads length bytes from the I/O stream. Length must be a non-negative integer or File#read will return empty string.

let file = "file.txt"
File.read(file)                 #=> "RbSwift\n"
File.read(file, offset: 1)      #=> "bSwift\n"
File.read(file, offset: 100)        #=> ""

Opens the file with File#open and writes the given string to I/O stream. The stream must be opened for writing.

File.open("empty.txt", "w") { file in
    file.write("Content")
}
let readFile = File.open("empty.txt", "r")
readFile.read()     #=> "Content"

Writes the given object(s) to I/O stream.

File.open("print-empty.txt", "w") { file in
    file.print("This is ", 10, " lines\n")
}
let file = File.open("print-empty.txt")
file.read()     #=> "This is 10 lines\n"

Writes the given object(s) to I/O stream. Writes a newline after any that do not already end with a newline sequence.

File.open("puts-empty.txt", "w") { file in
    file.puts("This", "is", "a", "test")
}
let file = File.open("puts-empty.txt")
file.read()     #=> "This\nis\na\ntest\n"

If obj is Numeric, write the character whose code is the least-significant byte of obj, otherwise write the first byte of the string representation of obj to I/O stream.

File.open("putc.txt", "w") { file in
    file.putc("aaa")
    file.putc(97)
}
let file = File.open("putc.txt")
file.read()     #=> "aa"

If obj is Numeric, write the character whose code is the least-significant byte of obj, otherwise write the first byte of the string representation of obj to I/O stream.

File.open("putc.txt", "w") { file in
    file.putc("aaa")
    file.putc(97)
}
let file = File.open("putc.txt")
file.read()     #=> "aa"

Reads length bytes from the I/O stream. Length must be a non-negative integer or File#read will return empty string.

let file = File.open("file.txt")
file.read(file)     #=> "RbSwift\n"
file.read(file)     #=> "bSwift\n"
file.read(file)     #=> ""

Writes the given string to I/O stream. The stream must be opened for writing.

File.open("empty.txt", "w") { file in
    file.write("Content")   #=> 7
}

Reads the next “line” from the I/O stream; lines are separated by sep. A separator of nil and a zero-length separator reads the entire contents.

let file = File.open("file.txt")
file.gets()     #=> "first line\n"
file.gets("s")  #=> "s"
file.gets()     #=> "econd line\n"

Reads a one-character string from IO stream. Returns nil if called at end of file.

let file = Fixture.name("file.txt")
File.open(file) { file in
    file.getc!      #=> "f"
}

let file = Fixture.name("file.txt")
File.open(file) { file in
    file.gets()
    file.gets()
    file.getc       #=> nil
}

Reads a one-character string from IO stream. Returns nil if called at end of file. An alias to IO#getc.

Reads the next “line” from the I/O stream; lines are separated by sep. A separator of nil and a zero-length separator reads the entire contents.

Flushes any buffered data within IO stream to the underlying operating system.

An enum value as the mapping of SEEK_SET/SEEK_CUR/SEEK_END

• set: SEEK_SEK
• cur: SEEK_CUR
• end: SEEK_END
• int: A custom seek position for IO#seek(offset:whence:)

Positions IO stream to the beginning of input, resetting lineno to zero.

file.rewind() <=> file.seek(0)

Seeks to a given offset in the stream according to the value of whence.

Closes I/O stream and flushes any pending writes to the operating system.

Returns an integer representing the numeric file descriptor for I/O stream.

An alias to fileno var.

Returns true if I/O stream is associated with a terminal device (tty), false otherwise.

The current offset (in bytes) of IO stream. Set this var to seek to the given position (in bytes) in IO stream. It is not guaranteed that seeking to the right position when IO stream is textmode.

Undocumented