Concatenates the given object(s) to str. If an object is an Integer, it is considered a codepoint and converted to a character before concatenation.
concat can take multiple arguments, and all the arguments are concatenated in order.
a = "hello " a.concat("world", 33) #=> "hello world!" a #=> "hello world!" b = "sn" b.concat("_", b, "_", b) #=> "sn_sn_sn"
See also String#<<, which takes a single argument.
Returns the string generated by calling crypt(3) standard library function with str and salt_str, in this order, as its arguments. Please do not use this method any longer. It is legacy; provided only for backward compatibility with ruby scripts in earlier days. It is bad to use in contemporary programs for several reasons:
* Behaviour of C's <code>crypt(3)</code> depends on the OS it is
run. The generated string lacks data portability.
* On some OSes such as Mac OS, <code>crypt(3)</code> never fails
(i.e. silently ends up in unexpected results).
* On some OSes such as Mac OS, <code>crypt(3)</code> is not
thread safe.
* So-called "traditional" usage of <code>crypt(3)</code> is very
very very weak. According to its manpage, Linux's traditional
<code>crypt(3)</code> output has only 2**56 variations; too
easy to brute force today. And this is the default behaviour.
* In order to make things robust some OSes implement so-called
"modular" usage. To go through, you have to do a complex
build-up of the <code>salt_str</code> parameter, by hand.
Failure in generation of a proper salt string tends not to
yield any errors; typos in parameters are normally not
detectable.
* For instance, in the following example, the second invocation
of <code>String#crypt</code> is wrong; it has a typo in
"round=" (lacks "s"). However the call does not fail and
something unexpected is generated.
"foo".crypt("$5$rounds=1000$salt$") # OK, proper usage
"foo".crypt("$5$round=1000$salt$") # Typo not detected
* Even in the "modular" mode, some hash functions are considered
archaic and no longer recommended at all; for instance module
<code>$1$</code> is officially abandoned by its author: see
http://phk.freebsd.dk/sagas/md5crypt_eol.html . For another
instance module <code>$3$</code> is considered completely
broken: see the manpage of FreeBSD.
* On some OS such as Mac OS, there is no modular mode. Yet, as
written above, <code>crypt(3)</code> on Mac OS never fails.
This means even if you build up a proper salt string it
generates a traditional DES hash anyways, and there is no way
for you to be aware of.
"foo".crypt("$5$rounds=1000$salt$") # => "$5fNPQMxC5j6."
If for some reason you cannot migrate to other secure contemporary password hashing algorithms, install the string-crypt gem and require 'string/crypt' to continue using it.
Returns the Symbol corresponding to str, creating the symbol if it did not previously exist. See Symbol#id2name.
"Koala".intern #=> :Koala s = 'cat'.to_sym #=> :cat s == :cat #=> true s = '@cat'.to_sym #=> :@cat s == :@cat #=> true
This can also be used to create symbols that cannot be represented using the :xxx notation.
'cat and dog'.to_sym #=> :"cat and dog"
Centers str in width. If width is greater than the length of str, returns a new String of length width with str centered and padded with padstr; otherwise, returns str.
"hello".center(4) #=> "hello" "hello".center(20) #=> " hello " "hello".center(20, '123') #=> "1231231hello12312312"
Returns a new String with the last character removed. If the string ends with \r\n, both characters are removed. Applying chop to an empty string returns an empty string. String#chomp is often a safer alternative, as it leaves the string unchanged if it doesn’t end in a record separator.
"string\r\n".chop #=> "string" "string\n\r".chop #=> "string\n" "string\n".chop #=> "string" "string".chop #=> "strin" "x".chop.chop #=> ""
Returns a copy of the receiver with trailing whitespace removed. See also String#lstrip and String#strip.
Refer to String#strip for the definition of whitespace.
" hello ".rstrip #=> " hello" "hello".rstrip #=> "hello"
Processes str as for String#chop, returning str, or nil if str is the empty string. See also String#chomp!.
Removes trailing whitespace from the receiver. Returns the altered receiver, or nil if no change was made. See also String#lstrip! and String#strip!.
Refer to String#strip for the definition of whitespace.
" hello ".rstrip! #=> " hello" " hello".rstrip! #=> nil "hello".rstrip! #=> nil
Returns 0 if the value is positive, pi otherwise.
Returns 0 if the value is positive, pi otherwise.
provides a unified clone operation, for REXML::XPathParser to use across multiple Object types
Returns an array with both numeric and float represented as Float objects.
This is achieved by converting numeric to a Float.
1.2.coerce(3) #=> [3.0, 1.2] 2.5.coerce(1.1) #=> [1.1, 2.5]
Returns true if float is 0.0.
Returns true if float is greater than 0.
Returns true if float is less than 0.
Returns the numerator. The result is machine dependent.
n = 0.3.numerator #=> 5404319552844595 d = 0.3.denominator #=> 18014398509481984 n.fdiv(d) #=> 0.3
See also Float#denominator.
Transfer control to another fiber, resuming it from where it last stopped or starting it if it was not resumed before. The calling fiber will be suspended much like in a call to Fiber.yield. You need to require 'fiber' before using this method.
The fiber which receives the transfer call is treats it much like a resume call. Arguments passed to transfer are treated like those passed to resume.
You cannot resume a fiber that transferred control to another one. This will cause a double resume error. You need to transfer control back to this fiber before it can yield and resume.
Example:
fiber1 = Fiber.new do puts "In Fiber 1" Fiber.yield end fiber2 = Fiber.new do puts "In Fiber 2" fiber1.transfer puts "Never see this message" end fiber3 = Fiber.new do puts "In Fiber 3" end fiber2.resume fiber3.resume
produces
In fiber 2 In fiber 1 In fiber 3
The optional encoding keyword argument specifies the encoding of the directory. If not specified, the filesystem encoding is used.
With no block, open is a synonym for Dir::new. If a block is present, it is passed aDir as a parameter. The directory is closed at the end of the block, and Dir::open returns the value of the block.
Seeks to a particular location in dir. integer must be a value returned by Dir#tell.
d = Dir.new("testdir") #=> #<Dir:0x401b3c40> d.read #=> "." i = d.tell #=> 12 d.read #=> ".." d.seek(i) #=> #<Dir:0x401b3c40> d.read #=> ".."
Closes the directory stream. Calling this method on closed Dir object is ignored since Ruby 2.3.
d = Dir.new("testdir") d.close #=> nil
Returns true if the named file is an empty directory, false if it is not a directory or non-empty.
Returns the last access time for the named file as a Time object.
file_name can be an IO object.
File.atime("testfile") #=> Wed Apr 09 08:51:48 CDT 2003
Returns the modification time for the named file as a Time object.
file_name can be an IO object.
File.mtime("testfile") #=> Tue Apr 08 12:58:04 CDT 2003
Returns the change time for the named file (the time at which directory information about the file was changed, not the file itself).
file_name can be an IO object.
Note that on Windows (NTFS), returns creation time (birth time).
File.ctime("testfile") #=> Wed Apr 09 08:53:13 CDT 2003