Dump the contents of a ruby object as JSON
.
This method is only expected to work with C Ruby. This is an experimental method and is subject to change. In particular, the function signature and output format are not guaranteed to be compatible in future versions of ruby.
Dump Ruby object o
to a YAML string. Optional options
may be passed in to control the output format. If an IO
object is passed in, the YAML will be dumped to that IO
object.
Example:
# Dump an array, get back a YAML string Psych.dump(['a', 'b']) # => "---\n- a\n- b\n" # Dump an array to an IO object Psych.dump(['a', 'b'], StringIO.new) # => #<StringIO:0x000001009d0890> # Dump an array with indentation set Psych.dump(['a', ['b']], :indentation => 3) # => "---\n- a\n- - b\n" # Dump an array to an IO with indentation set Psych.dump(['a', ['b']], StringIO.new, :indentation => 3)
Calculates Adler-32 checksum for string
, and returns updated value of adler
. If string
is omitted, it returns the Adler-32 initial value. If adler
is omitted, it assumes that the initial value is given to adler
.
Example usage:
require "zlib" data = "foo" puts "Adler32 checksum: #{Zlib.adler32(data).to_s(16)}" #=> Adler32 checksum: 2820145
Returns true
if the named file is readable by the effective user and group id of this process. See eaccess(3).
Returns true
if the named file is writable by the effective user and group id of this process. See eaccess(3).
Returns true
if the named file is executable by the effective user and group id of this process. See eaccess(3).
Returns true
if the named file
exists and is a regular file.
file
can be an IO
object.
If the file
argument is a symbolic link, it will resolve the symbolic link and use the file referenced by the link.
Enables garbage collection, returning true
if garbage collection was previously disabled.
GC.disable #=> false GC.enable #=> true GC.enable #=> false
Disables garbage collection, returning true
if garbage collection was already disabled.
GC.disable #=> false GC.disable #=> true
Returns the Base64-decoded version of str
. This method complies with RFC 2045. Characters outside the base alphabet are ignored.
require 'base64' str = 'VGhpcyBpcyBsaW5lIG9uZQpUaGlzIG' + 'lzIGxpbmUgdHdvClRoaXMgaXMgbGlu' + 'ZSB0aHJlZQpBbmQgc28gb24uLi4K' puts Base64.decode64(str)
Generates:
This is line one This is line two This is line three And so on...
Options: (none)
Returns true if new
is newer than all old_list
. Non-existent files are older than any file.
FileUtils.uptodate?('hello.o', %w(hello.c hello.h)) or \ system 'make hello.o'
Options: (none)
Returns true if new
is newer than all old_list
. Non-existent files are older than any file.
FileUtils.uptodate?('hello.o', %w(hello.c hello.h)) or \ system 'make hello.o'
See Mutex#sleep
Escapes a string so that it can be safely used in a Bourne shell command line. str
can be a non-string object that responds to to_s
.
Note that a resulted string should be used unquoted and is not intended for use in double quotes nor in single quotes.
argv = Shellwords.escape("It's better to give than to receive") argv #=> "It\\'s\\ better\\ to\\ give\\ than\\ to\\ receive"
String#shellescape
is a shorthand for this function.
argv = "It's better to give than to receive".shellescape argv #=> "It\\'s\\ better\\ to\\ give\\ than\\ to\\ receive" # Search files in lib for method definitions pattern = "^[ \t]*def " open("| grep -Ern #{pattern.shellescape} lib") { |grep| grep.each_line { |line| file, lineno, matched_line = line.split(':', 3) # ... } }
It is the caller’s responsibility to encode the string in the right encoding for the shell environment where this string is used.
Multibyte characters are treated as multibyte characters, not as bytes.
Returns an empty quoted String if str
has a length of zero.
Escapes a string so that it can be safely used in a Bourne shell command line. str
can be a non-string object that responds to to_s
.
Note that a resulted string should be used unquoted and is not intended for use in double quotes nor in single quotes.
argv = Shellwords.escape("It's better to give than to receive") argv #=> "It\\'s\\ better\\ to\\ give\\ than\\ to\\ receive"
String#shellescape
is a shorthand for this function.
argv = "It's better to give than to receive".shellescape argv #=> "It\\'s\\ better\\ to\\ give\\ than\\ to\\ receive" # Search files in lib for method definitions pattern = "^[ \t]*def " open("| grep -Ern #{pattern.shellescape} lib") { |grep| grep.each_line { |line| file, lineno, matched_line = line.split(':', 3) # ... } }
It is the caller’s responsibility to encode the string in the right encoding for the shell environment where this string is used.
Multibyte characters are treated as multibyte characters, not as bytes.
Returns an empty quoted String if str
has a length of zero.
Raises a TypeError
to prevent duping.
By default, do not retain any state when marshalling.
Serializes obj and all descendant objects. If anIO is specified, the serialized data will be written to it, otherwise the data will be returned as a String. If limit is specified, the traversal of subobjects will be limited to that depth. If limit is negative, no checking of depth will be performed.
class Klass def initialize(str) @str = str end def say_hello @str end end
(produces no output)
o = Klass.new("hello\n") data = Marshal.dump(o) obj = Marshal.load(data) obj.say_hello #=> "hello\n"
Marshal
can’t dump following objects:
anonymous Class/Module.
objects which are related to system (ex: Dir
, File::Stat
, IO
, File
, Socket
and so on)
an instance of MatchData
, Data
, Method
, UnboundMethod
, Proc
, Thread
, ThreadGroup
, Continuation
objects which define singleton methods