creates a UNIX socket server on path. It calls the block for each socket accepted.
If host is specified, it is used with port to determine the server ports.
The socket is not closed when the block returns. So application should close it.
This method deletes the socket file pointed by path at first if the file is a socket file and it is owned by the user of the application. This is safe only if the directory of path is not changed by a malicious user. So don’t use /tmp/malicious-users-directory/socket. Note that /tmp/socket and /tmp/your-private-directory/socket is safe assuming that /tmp has sticky bit.
# Sequential echo server. # It services only one client at a time. Socket.unix_server_loop("/tmp/sock") {|sock, client_addrinfo| begin IO.copy_stream(sock, sock) ensure sock.close end }
Returns the size of optional parameters.
tobj = WIN32OLE_TYPE.new('Microsoft Excel 9.0 Object Library', 'Workbook') method = WIN32OLE_METHOD.new(tobj, 'SaveAs') puts method.size_opt_params # => 4
Task
description for the rdoc task or its renamed equivalent
Returns the class for the given object
.
class A def foo ObjectSpace::trace_object_allocations do obj = Object.new p "#{ObjectSpace::allocation_class_path(obj)}" end end end A.new.foo #=> "Class"
See ::trace_object_allocations
for more information and examples.
Specifies a Proc
object proc
to determine if a character in the user’s input is escaped. It should take the user’s input and the index of the character in question as input, and return a boolean (true if the specified character is escaped).
Readline
will only call this proc with characters specified in completer_quote_characters
, to discover if they indicate the end of a quoted argument, or characters specified in completer_word_break_characters
, to discover if they indicate a break between arguments.
If completer_quote_characters
is not set, or if the user input doesn’t contain one of the completer_quote_characters
or a ++ character, Readline
will not attempt to use this proc at all.
Raises ArgumentError
if proc
does not respond to the call method.
Returns the quoting detection Proc
object.
Sets whether or not to ignore case on completion.
Returns true if completion ignores case. If no, returns false.
NOTE: Returns the same object that is specified by Readline.completion_case_fold=
method.
require "readline" Readline.completion_case_fold = "This is a String." p Readline.completion_case_fold # => "This is a String."
Sets a list of characters which can be used to quote a substring of the line. Completion occurs on the entire substring, and within the substring Readline.completer_word_break_characters
are treated as any other character, unless they also appear within this list.
Raises NotImplementedError
if the using readline library does not support.
Gets a list of characters which can be used to quote a substring of the line.
Raises NotImplementedError
if the using readline library does not support.
The file name and line number of the caller of the caller of this method.
depth
is how many layers up the call stack it should go.
e.g.,
def a; Gem.location_of_caller
; end a #=> [“x.rb”, 2] # (it’ll vary depending on file name and line number)
def b; c; end def c; Gem.location_of_caller(2)
; end b #=> [“x.rb”, 6] # (it’ll vary depending on file name and line number)
Returns a String
containing the API compatibility version of Ruby
Returns the latest release version of RubyGems.
Returns the version of the latest release-version of gem name
User Code Block
Get a single optional argument from the command line. If more than one argument is given, return only the first. Return nil if none are given.
Iterates backwards over array elements.
When a block given, passes, in reverse order, each element to the block; returns self
:
a = [:foo, 'bar', 2] a.reverse_each {|element| puts "#{element.class} #{element}" }
Output:
Integer 2 String bar Symbol foo
Allows the array to be modified during iteration:
a = [:foo, 'bar', 2] a.reverse_each {|element| puts element; a.clear if element.to_s.start_with?('b') }
Output:
2 bar
When no block given, returns a new Enumerator:
a = [:foo, 'bar', 2] e = a.reverse_each e # => #<Enumerator: [:foo, "bar", 2]:reverse_each> a1 = e.each {|element| puts "#{element.class} #{element}" }
Output:
Integer 2 String bar Symbol foo
Related: each
, each_index
.
Calls the block with each repeated combination of length n
of the elements of self
; each combination is an Array; returns self
. The order of the combinations is indeterminate.
When a block and a positive Integer argument n
are given, calls the block with each n
-tuple repeated combination of the elements of self
. The number of combinations is (n+1)(n+2)/2
.
n
= 1:
a = [0, 1, 2] a.repeated_combination(1) {|combination| p combination }
Output:
[0] [1] [2]
n
= 2:
a.repeated_combination(2) {|combination| p combination }
Output:
[0, 0] [0, 1] [0, 2] [1, 1] [1, 2] [2, 2]
If n
is zero, calls the block once with an empty Array.
If n
is negative, does not call the block:
a.repeated_combination(-1) {|combination| fail 'Cannot happen' }
Returns a new Enumerator if no block given:
a = [0, 1, 2] a.repeated_combination(2) # => #<Enumerator: [0, 1, 2]:combination(2)>
Using Enumerators, it’s convenient to show the combinations and counts for some values of n
:
e = a.repeated_combination(0) e.size # => 1 e.to_a # => [[]] e = a.repeated_combination(1) e.size # => 3 e.to_a # => [[0], [1], [2]] e = a.repeated_combination(2) e.size # => 6 e.to_a # => [[0, 0], [0, 1], [0, 2], [1, 1], [1, 2], [2, 2]]
Like backtrace
, but returns each line of the execution stack as a Thread::Backtrace::Location
. Accepts the same arguments as backtrace
.
f = Fiber.new { Fiber.yield } f.resume loc = f.backtrace_locations.first loc.label #=> "yield" loc.path #=> "test.rb" loc.lineno #=> 1