Executes the block for every line in the named I/O port, where lines are separated by sep.
If no block is given, an enumerator is returned instead.
If name starts with a pipe character ("|") and the receiver is the IO class, a subprocess is created in the same way as Kernel#open, and its output is returned. Consider to use File.foreach to disable the behavior of subprocess invocation.
File.foreach("testfile") {|x| print "GOT ", x } IO.foreach("| cat testfile") {|x| print "GOT ", x }
produces:
GOT This is line one GOT This is line two GOT This is line three GOT And so on...
If the last argument is a hash, it’s the keyword argument to open. See IO.readlines for details about getline_args. And see also IO.read for details about open_args.
If obj is Numeric, write the character whose code is the least-significant byte of obj. If obj is String, write the first character of obj to ios. Otherwise, raise TypeError.
$stdout.putc "A" $stdout.putc 65
produces:
AA
Executes the block for every line in ios, where lines are separated by sep. ios must be opened for reading or an IOError will be raised.
If no block is given, an enumerator is returned instead.
f = File.new("testfile") f.each {|line| puts "#{f.lineno}: #{line}" }
produces:
1: This is line one 2: This is line two 3: This is line three 4: And so on...
See IO.readlines for details about getline_args.
Immediately writes to disk all data buffered in the stream, via the operating system’s: fdatasync(2), if supported, otherwise via fsync(2), if supported; otherwise raises an exception.
Reads a one-character string from ios. Returns nil if called at end of file.
f = File.new("testfile") f.getc #=> "h" f.getc #=> "e"
Reads a one-character string from ios. Raises an EOFError on end of file.
f = File.new("testfile") f.readchar #=> "h" f.readchar #=> "e"
Pushes back characters (passed as a parameter) onto ios, such that a subsequent buffered read will return it. It is only guaranteed to support a single byte, and only if ungetbyte or ungetc has not already been called on ios since the previous read of at least a single byte from ios. However, it can support additional bytes if there is space in the internal buffer to allow for it.
f = File.new("testfile") #=> #<File:testfile> c = f.getc #=> "8" f.ungetc(c) #=> nil f.getc #=> "8"
If given an integer, the integer must represent a valid codepoint in the external encoding of ios.
Calling this method prepends to the existing buffer, even if the method has already been called previously:
f = File.new("testfile") #=> #<File:testfile> f.ungetc("ab") #=> nil f.ungetc("cd") #=> nil f.read(5) #=> "cdab8"
Has no effect with unbuffered reads (such as IO#sysread).
Returns true if ios is associated with a terminal device (tty), false otherwise.
File.new("testfile").isatty #=> false File.new("/dev/tty").isatty #=> true
Puts ios into binary mode. Once a stream is in binary mode, it cannot be reset to nonbinary mode.
newline conversion disabled
encoding conversion disabled
content is treated as ASCII-8BIT
Returns true if ios is binmode.
With a block given, passes each element of self to the block:
a = [] (1..4).each {|element| a.push(element) } # => 1..4 a # => [1, 2, 3, 4]
Raises an exception unless self.first.respond_to?(:succ).
With no block given, returns an enumerator.
Returns the maximum value in self, using method <=> or a given block for comparison.
With no argument and no block given, returns the maximum-valued element of self.
(1..4).max # => 4 ('a'..'d').max # => "d" (-4..-1).max # => -1
With non-negative integer argument n given, and no block given, returns the n maximum-valued elements of self in an array:
(1..4).max(2) # => [4, 3] ('a'..'d').max(2) # => ["d", "c"] (-4..-1).max(2) # => [-1, -2] (1..4).max(50) # => [4, 3, 2, 1]
If a block is given, it is called:
First, with the first two element of self.
Then, sequentially, with the so-far maximum value and the next element of self.
To illustrate:
(1..4).max {|a, b| p [a, b]; a <=> b } # => 4
Output:
[2, 1] [3, 2] [4, 3]
With no argument and a block given, returns the return value of the last call to the block:
(1..4).max {|a, b| -(a <=> b) } # => 1
With non-negative integer argument n given, and a block given, returns the return values of the last n calls to the block in an array:
(1..4).max(2) {|a, b| -(a <=> b) } # => [1, 2] (1..4).max(50) {|a, b| -(a <=> b) } # => [1, 2, 3, 4]
Returns an empty array if n is zero:
(1..4).max(0) # => [] (1..4).max(0) {|a, b| -(a <=> b) } # => []
Returns nil or an empty array if:
The begin value of the range is larger than the end value:
(4..1).max # => nil (4..1).max(2) # => [] (4..1).max {|a, b| -(a <=> b) } # => nil (4..1).max(2) {|a, b| -(a <=> b) } # => []
The begin value of an exclusive range is equal to the end value:
(1...1).max # => nil (1...1).max(2) # => [] (1...1).max {|a, b| -(a <=> b) } # => nil (1...1).max(2) {|a, b| -(a <=> b) } # => []
Raises an exception if either:
self is a endless range: (1..).
A block is given and self is a beginless range.
Related: Range#min, Range#minmax.
Returns a new set that is a copy of the set, flattening each containing set recursively.
Equivalent to Set#flatten, but replaces the receiver with the result in place. Returns nil if no modifications were made.
Calls the given block once for each element in the set, passing the element as parameter. Returns an enumerator if no block is given.
Allocates space for a new object of class’s class and does not call initialize on the new instance. The returned object must be an instance of class.
klass = Class.new do def initialize(*args) @initialized = true end def initialized? @initialized || false end end klass.allocate.initialized? #=> false
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.
The opposite of Pathname#absolute?
It returns false if the pathname begins with a slash.
p = Pathname.new('/im/sure') p.relative? #=> false p = Pathname.new('not/so/sure') p.relative? #=> true
Returns the children of the directory (files and subdirectories, not recursive) as an array of Pathname objects.
By default, the returned pathnames will have enough information to access the files. If you set with_directory to false, then the returned pathnames will contain the filename only.
For example:
pn = Pathname("/usr/lib/ruby/1.8")
pn.children
# -> [ Pathname:/usr/lib/ruby/1.8/English.rb,
Pathname:/usr/lib/ruby/1.8/Env.rb,
Pathname:/usr/lib/ruby/1.8/abbrev.rb, ... ]
pn.children(false)
# -> [ Pathname:English.rb, Pathname:Env.rb, Pathname:abbrev.rb, ... ]
Note that the results never contain the entries . and .. in the directory because they are not children.
Creates a full path, including any intermediate directories that don’t yet exist.
See FileUtils.mkpath and FileUtils.mkdir_p
Returns the real (absolute) pathname for self in the actual filesystem.
Does not contain symlinks or useless dots, .. and ..
All components of the pathname must exist when this method is called.
Returns the real (absolute) pathname of self in the actual filesystem.
Does not contain symlinks or useless dots, .. and ..
The last component of the real pathname can be nonexistent.