Returns true if time represents Monday.
t = Time.local(2003, 8, 4) #=> 2003-08-04 00:00:00 -0500 t.monday? #=> true
Deletes all data from the database.
Returns a Hash (not a DBM database) created by using each value in the database as a key, with the corresponding key as its value.
Flushes input and output buffers in kernel.
You must require ‘io/console’ to use this method.
Reads and returns a line without echo back. Prints prompt unless it is nil.
You must require ‘io/console’ to use this method.
Returns an File instance opened console.
If sym is given, it will be sent to the opened console with args and the result will be returned instead of the console IO itself.
You must require ‘io/console’ to use this method.
Returns true if an IO object is in non-blocking mode.
Enables non-blocking mode on a stream when set to true, and blocking mode when set to false.
Yields self in non-blocking mode.
When false is given as an argument, self is yielded in blocking mode. The original mode is restored after the block is executed.
Waits until IO is readable or writable without blocking and returns self, or nil when times out. Returns true immediately when buffered data is available. Optional parameter mode is one of :read, :write, or :read_write.
Opens the file, optionally seeks to the given offset, writes string, then returns the length written. write ensures the file is closed before returning. If offset is not given in write mode, the file is truncated. Otherwise, it is not truncated.
IO.write("testfile", "0123456789", 20) #=> 10 # File could contain: "This is line one\nThi0123456789two\nThis is line three\nAnd so on...\n" IO.write("testfile", "0123456789") #=> 10 # File would now read: "0123456789"
If the last argument is a hash, it specifies options for the internal open(). It accepts the following keys:
string or encoding
Specifies the encoding of the read string. See Encoding.aliases for possible encodings.
string or integer
Specifies the mode argument for open(). It must start with “w”, “a”, or “r+”, otherwise it will cause an error. See IO.new for the list of possible modes.
integer
Specifies the perm argument for open().
array
Specifies arguments for open() as an array. This key can not be used in combination with other keys.
Same as IO.write except opening the file in binary mode and ASCII-8BIT encoding (“wb:ASCII-8BIT”).
This is a deprecated alias for each_char.
Writes the given string to ios using a low-level write. Returns the number of bytes written. Do not mix with other methods that write to ios or you may get unpredictable results. Raises SystemCallError on error.
f = File.new("out", "w") f.syswrite("ABCDEF") #=> 6
Writes the given string to ios at offset using pwrite() system call. This is advantageous to combining IO#seek and IO#write in that it is atomic, allowing multiple threads/process to share the same IO object for reading the file at various locations. This bypasses any userspace buffering of the IO layer. Returns the number of bytes written. Raises SystemCallError on error and NotImplementedError if platform does not implement the system call.
File.open("out", "w") do |f| f.pwrite("ABCDEF", 3) #=> 6 end File.read("out") #=> "\u0000\u0000\u0000ABCDEF"
Writes the given strings to ios. The stream must be opened for writing. Arguments that are not a string will be converted to a string using to_s. Returns the number of bytes written in total.
count = $stdout.write("This is", " a test\n") puts "That was #{count} bytes of data"
produces:
This is a test That was 15 bytes of data
Reads a one-character string from ios. Raises an EOFError on end of file.
f = File.new("testfile") f.readchar #=> "h" f.readchar #=> "e"
Provides a mechanism for issuing low-level commands to control or query I/O devices. Arguments and results are platform dependent. If arg is a number, its value is passed directly. If it is a string, it is interpreted as a binary sequence of bytes. On Unix platforms, see ioctl(2) for details. Not implemented on all platforms.
Removes all the key-value pairs within gdbm.
Returns a hash created by using gdbm’s values as keys, and the keys as values.
By using binary search, finds a value in range which meets the given condition in O(log n) where n is the size of the range.
You can use this method in two use cases: a find-minimum mode and a find-any mode. In either case, the elements of the range must be monotone (or sorted) with respect to the block.
In find-minimum mode (this is a good choice for typical use case), the block must return true or false, and there must be a value x so that:
the block returns false for any value which is less than x, and
the block returns true for any value which is greater than or equal to x.
If x is within the range, this method returns the value x. Otherwise, it returns nil.
ary = [0, 4, 7, 10, 12] (0...ary.size).bsearch {|i| ary[i] >= 4 } #=> 1 (0...ary.size).bsearch {|i| ary[i] >= 6 } #=> 2 (0...ary.size).bsearch {|i| ary[i] >= 8 } #=> 3 (0...ary.size).bsearch {|i| ary[i] >= 100 } #=> nil (0.0...Float::INFINITY).bsearch {|x| Math.log(x) >= 0 } #=> 1.0
In find-any mode (this behaves like libc’s bsearch(3)), the block must return a number, and there must be two values x and y (x <= y) so that:
the block returns a positive number for v if v < x,
the block returns zero for v if x <= v < y, and
the block returns a negative number for v if y <= v.
This method returns any value which is within the intersection of the given range and x…y (if any). If there is no value that satisfies the condition, it returns nil.
ary = [0, 100, 100, 100, 200] (0..4).bsearch {|i| 100 - ary[i] } #=> 1, 2 or 3 (0..4).bsearch {|i| 300 - ary[i] } #=> nil (0..4).bsearch {|i| 50 - ary[i] } #=> nil
You must not mix the two modes at a time; the block must always return either true/false, or always return a number. It is undefined which value is actually picked up at each iteration.
provides a unified clone operation, for REXML::XPathParser to use across multiple Object types
Same as sym.to_s.capitalize.intern.
Callback invoked whenever a subclass of the current class is created.
Example:
class Foo def self.inherited(subclass) puts "New subclass: #{subclass}" end end class Bar < Foo end class Baz < Bar end
produces:
New subclass: Bar New subclass: Baz
Returns clean pathname of self with consecutive slashes and useless dots removed. The filesystem is not accessed.
If consider_symlink is true, then a more conservative algorithm is used to avoid breaking symbolic linkages. This may retain more .. entries than absolutely necessary, but without accessing the filesystem, this can’t be avoided.
See Pathname#realpath.