Prepends each string in other_strings to self and returns self:
s = 'foo' s.prepend('bar', 'baz') # => "barbazfoo" s # => "barbazfoo"
Related: String#concat.
Returns self modulo other as a float.
For float f and real number r, these expressions are equivalent:
f % r f-r*(f/r).floor f.divmod(r)[1]
See Numeric#divmod.
Examples:
10.0 % 2 # => 0.0 10.0 % 3 # => 1.0 10.0 % 4 # => 2.0 10.0 % -2 # => 0.0 10.0 % -3 # => -2.0 10.0 % -4 # => -2.0 10.0 % 4.0 # => 2.0 10.0 % Rational(4, 1) # => 2.0
Returns a 2-element array [q, r], where
q = (self/other).floor # Quotient r = self % other # Remainder
Examples:
11.0.divmod(4) # => [2, 3.0] 11.0.divmod(-4) # => [-3, -1.0] -11.0.divmod(4) # => [-3, 1.0] -11.0.divmod(-4) # => [2, -3.0] 12.0.divmod(4) # => [3, 0.0] 12.0.divmod(-4) # => [-3, 0.0] -12.0.divmod(4) # => [-3, -0.0] -12.0.divmod(-4) # => [3, -0.0] 13.0.divmod(4.0) # => [3, 1.0] 13.0.divmod(Rational(4, 1)) # => [3, 1.0]
Returns true if self is greater than 0, false otherwise.
Returns true if self is less than 0, false otherwise.
Returns the current fiber. If you are not running in the context of a fiber this method will return the root fiber.
Resumes the fiber from the point at which the last Fiber.yield was called, or starts running it if it is the first call to resume. Arguments passed to resume will be the value of the Fiber.yield expression or will be passed as block parameters to the fiber’s block if this is the first resume.
Alternatively, when resume is called it evaluates to the arguments passed to the next Fiber.yield statement inside the fiber’s block or to the block value if it runs to completion without any Fiber.yield
Returns true if the fiber can still be resumed (or transferred to). After finishing execution of the fiber block this method will always return false.
Calls the block with each entry name in the directory at dirpath; sets the given encoding onto each passed entry_name:
Dir.foreach('/example') {|entry_name| p entry_name }
Output:
"config.h" "lib" "main.rb" ".." "."
Encoding:
Dir.foreach('/example') {|entry_name| p entry_name.encoding; break } Dir.foreach('/example', encoding: 'US-ASCII') {|entry_name| p entry_name.encoding; break }
Output:
#<Encoding:UTF-8> #<Encoding:US-ASCII>
See String Encoding.
Returns an enumerator if no block is given.
Returns an array of the entry names in the directory at dirpath except for '.' and '..'; sets the given encoding onto each returned entry name:
Dir.children('/example') # => ["config.h", "lib", "main.rb"] Dir.children('/example').first.encoding # => #<Encoding:UTF-8> Dir.children('/example', encoding: 'US-ASCII').first.encoding # => #<Encoding:US-ASCII>
See String Encoding.
Raises an exception if the directory does not exist.
Reads and returns the next entry name from self; returns nil if at end-of-stream; see Dir As Stream-Like:
dir = Dir.new('example') dir.read # => "." dir.read # => ".." dir.read # => "config.h"
Returns an array of the entry names in self except for '.' and '..':
dir = Dir.new('/example') dir.children # => ["config.h", "lib", "main.rb"]
Sets the position in self to zero; see Dir As Stream-Like:
dir = Dir.new('example') dir.read # => "." dir.read # => ".." dir.pos # => 2 dir.rewind # => #<Dir:example> dir.pos # => 0
Returns whether dirpath specifies an empty directory:
dirpath = '/tmp/foo' Dir.mkdir(dirpath) Dir.empty?(dirpath) # => true Dir.empty?('/example') # => false Dir.empty?('/example/main.rb') # => false
Raises an exception if dirpath does not specify a directory or file in the underlying file system.
Changes permission bits on the named file(s) to the bit pattern represented by mode_int. Actual effects are operating system dependent (see the beginning of this section). On Unix systems, see chmod(2) for details. Returns the number of files processed.
File.chmod(0644, "testfile", "out") #=> 2
Equivalent to File::chmod, but does not follow symbolic links (so it will change the permissions associated with the link, not the file referenced by the link). Often not available.
Returns the name of the file referenced by the given link. Not available on all platforms.
File.symlink("testfile", "link2test") #=> 0 File.readlink("link2test") #=> "testfile"
Renames the given file to the new name. Raises a SystemCallError if the file cannot be renamed.
File.rename("afile", "afile.bak") #=> 0
Returns the real (absolute) pathname of pathname in the actual filesystem not containing symlinks or useless dots.
If dir_string is given, it is used as a base directory for interpreting relative pathname instead of the current directory.
All components of the pathname must exist when this method is called.
Returns the real (absolute) pathname of pathname in the actual filesystem. The real pathname doesn’t contain symlinks or useless dots.
If dir_string is given, it is used as a base directory for interpreting relative pathname instead of the current directory.
The last component of the real pathname can be nonexistent.
Changes permission bits on file to the bit pattern represented by mode_int. Actual effects are platform dependent; on Unix systems, see chmod(2) for details. Follows symbolic links. Also see File#lchmod.
f = File.new("out", "w"); f.chmod(0644) #=> 0
With string object given, returns true if path is a string path leading to a directory, or to a symbolic link to a directory; false otherwise:
File.directory?('.') # => true File.directory?('foo') # => false File.symlink('.', 'dirlink') # => 0 File.directory?('dirlink') # => true File.symlink('t,txt', 'filelink') # => 0 File.directory?('filelink') # => false
Argument path can be an IO object.
Returns true if the named file is readable by the effective user and group id of this process. See eaccess(3).
Note that some OS-level security features may cause this to return true even though the file is not readable by the effective user/group.
Returns true if the named file exists and has a zero size.
file_name can be an IO object.
Rewinds the enumeration sequence to the beginning.
If the enclosed object responds to a “rewind” method, it is called.