Returns true if float is a valid IEEE floating point number (it is not infinite, and Float#nan? is false).
Returns a string containing a representation of self. As well as a fixed or exponential form of the float, the call may return NaN, Infinity, and -Infinity.
Return a string describing this Dir object.
Repositions dir to the first entry.
d = Dir.new("testdir") d.read #=> "." d.rewind #=> #<Dir:0x401b3fb0> d.read #=> "."
Deletes the named directory. Raises a subclass of SystemCallError if the directory isn’t empty.
Creates a new name for an existing file using a hard link. Will not overwrite new_name if it already exists (raising a subclass of SystemCallError). Not available on all platforms.
File.link("testfile", ".testfile") #=> 0 IO.readlines(".testfile")[0] #=> "This is line one\n"
Creates a symbolic link called new_name for the existing file old_name. Raises a NotImplemented exception on platforms that do not support symbolic links.
File.symlink("testfile", "link2test") #=> 0
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"
Deletes the named files, returning the number of names passed as arguments. Raises an exception on any error. See also Dir::rmdir.
Returns the current umask value for this process. If the optional argument is given, set the umask to that value and return the previous value. Umask values are subtracted from the default permissions, so a umask of 0222 would make a file read-only for everyone.
File.umask(0006) #=> 18 File.umask #=> 6
Returns a new string formed by joining the strings using File::SEPARATOR.
File.join("usr", "mail", "gumby") #=> "usr/mail/gumby"
Returns true if the named file is a symbolic link.
Returns a string which represents the encoding for programmers.
Encoding::UTF_8.inspect #=> "#<Encoding:UTF-8>" Encoding::ISO_2022_JP.inspect #=> "#<Encoding:ISO-2022-JP (dummy)>"
Search the encoding with specified name. name should be a string.
Encoding.find("US-ASCII") #=> #<Encoding:US-ASCII>
Names which this method accept are encoding names and aliases including following special aliases
default external encoding
default internal encoding
locale encoding
filesystem encoding
An ArgumentError is raised when no encoding with name. Only Encoding.find("internal") however returns nil when no encoding named “internal”, in other words, when Ruby has no default internal encoding.
Rewinds the enumeration sequence to the beginning.
If the enclosed object responds to a “rewind” method, it is called.
Creates a printable version of e.
Return this exception’s class name and message
Invokes Module.append_features on each parameter in reverse order.
Import class refinements from module into the current class or module definition.
Returns the list of Modules nested at the point of call.
module M1 module M2 $a = Module.nesting end end $a #=> [M1::M2, M1] $a[0].name #=> "M1::M2"
Callback invoked whenever the receiver is included in another module or class. This should be used in preference to Module.append_features if your code wants to perform some action when a module is included in another.
module A def A.included(mod) puts "#{self} included in #{mod}" end end module Enumerable include A end # => prints "A included in Enumerable"
Returns true if module is included in mod or one of mod’s ancestors.
module A end class B include A end class C < B end B.include?(A) #=> true C.include?(A) #=> true A.include?(A) #=> false
Returns a string representing this module or class. For basic classes and modules, this is the name. For singletons, we show information on the thing we’re attached to as well.