Controls tracing of assignments to global variables. The parameter symbol
identifies the variable (as either a string name or a symbol identifier). cmd (which may be a string or a Proc
object) or block is executed whenever the variable is assigned. The block or Proc
object receives the variable’s new value as a parameter. Also see Kernel::untrace_var.
trace_var :$_, proc {|v| puts "$_ is now '#{v}'" } $_ = "hello" $_ = ' there'
produces:
$_ is now 'hello' $_ is now ' there'
Removes tracing for the specified command on the given global variable and returns nil
. If no command is specified, removes all tracing for that variable and returns an array containing the commands actually removed.
Initializes the MonitorMixin
after being included in a class or when an object has been extended with the MonitorMixin
Returns the source file origin from the given object
.
See ::trace_object_allocations
for more information and examples.
Adds aProc as a finalizer, to be called after obj was destroyed. The object ID of the obj will be passed as an argument to aProc. If aProc is a lambda or method, make sure it can be called with a single argument.
The return value is an array [0, aProc]
.
The two recommended patterns are to either create the finaliser proc in a non-instance method where it can safely capture the needed state, or to use a custom callable object that stores the needed state explicitly as instance variables.
class Foo def initialize(data_needed_for_finalization) ObjectSpace.define_finalizer(self, self.class.create_finalizer(data_needed_for_finalization)) end def self.create_finalizer(data_needed_for_finalization) proc { puts "finalizing #{data_needed_for_finalization}" } end end class Bar class Remover def initialize(data_needed_for_finalization) @data_needed_for_finalization = data_needed_for_finalization end def call(id) puts "finalizing #{@data_needed_for_finalization}" end end def initialize(data_needed_for_finalization) ObjectSpace.define_finalizer(self, Remover.new(data_needed_for_finalization)) end end
Note that if your finalizer references the object to be finalized it will never be run on GC
, although it will still be run at exit. You will get a warning if you capture the object to be finalized as the receiver of the finalizer.
class CapturesSelf def initialize(name) ObjectSpace.define_finalizer(self, proc { # this finalizer will only be run on exit puts "finalizing #{name}" }) end end
Also note that finalization can be unpredictable and is never guaranteed to be run except on exit.
Removes all finalizers for obj.
Returns the version of libyaml being used
Returns the string which represents the version of zlib library.
Returns a string containing the RFC-2045-compliant Base64-encoding of bin
.
Per RFC 2045, the returned string may contain the URL-unsafe characters +
or /
; see Encoding Character Set above:
Base64.strict_encode64("\xFB\xEF\xBE") # => "++++\n" Base64.strict_encode64("\xFF\xFF\xFF") # => "////\n"
The returned string may include padding; see Padding above.
Base64.strict_encode64('*') # => "Kg==\n"
The returned string will have no newline characters, regardless of its length; see Newlines above:
Base64.strict_encode64('*') # => "Kg==" Base64.strict_encode64('*' * 46) # => "KioqKioqKioqKioqKioqKioqKioqKioqKioqKioqKioqKioqKioqKioqKioqKg=="
The string to be encoded may itself contain newlines, which will be encoded as ordinary Base64:
Base64.strict_encode64("\n\n\n") # => "CgoK" s = "This is line 1\nThis is line 2\n" Base64.strict_encode64(s) # => "VGhpcyBpcyBsaW5lIDEKVGhpcyBpcyBsaW5lIDIK"
Returns a string containing the decoding of an RFC-2045-compliant Base64-encoded string str
:
s = "VGhpcyBpcyBsaW5lIDEKVGhpcyBpcyBsaW5lIDIK" Base64.strict_decode64(s) # => "This is line 1\nThis is line 2\n"
Non-Base64 characters in str
not allowed; see Encoding Character Set above: these include newline characters and characters -
and /
:
Base64.strict_decode64("\n") # Raises ArgumentError Base64.strict_decode64('-') # Raises ArgumentError Base64.strict_decode64('_') # Raises ArgumentError
Padding in str
, if present, must be correct:
Base64.strict_decode64("MDEyMzQ1Njc") # Raises ArgumentError Base64.strict_decode64("MDEyMzQ1Njc=") # => "01234567" Base64.strict_decode64("MDEyMzQ1Njc==") # Raises ArgumentError
Adds a post-installs hook that will be passed a Gem::DependencyInstaller
and a list of installed specifications when Gem::DependencyInstaller#install
is complete
An Array
of the default sources that come with RubyGems
Creates hard links; returns nil
.
Arguments src
and dest
should be interpretable as paths.
If src
is the path to a file and dest
does not exist, creates a hard link at dest
pointing to src
:
FileUtils.touch('src0.txt') File.exist?('dest0.txt') # => false FileUtils.link_entry('src0.txt', 'dest0.txt') File.file?('dest0.txt') # => true
If src
is the path to a directory and dest
does not exist, recursively creates hard links at dest
pointing to paths in src
:
FileUtils.mkdir_p(['src1/dir0', 'src1/dir1']) src_file_paths = [ 'src1/dir0/t0.txt', 'src1/dir0/t1.txt', 'src1/dir1/t2.txt', 'src1/dir1/t3.txt', ] FileUtils.touch(src_file_paths) File.directory?('dest1') # => true FileUtils.link_entry('src1', 'dest1') File.file?('dest1/dir0/t0.txt') # => true File.file?('dest1/dir0/t1.txt') # => true File.file?('dest1/dir1/t2.txt') # => true File.file?('dest1/dir1/t3.txt') # => true
Keyword arguments:
dereference_root: true
- dereferences src
if it is a symbolic link.
remove_destination: true
- removes dest
before creating links.
Raises an exception if dest
is the path to an existing file or directory and keyword argument remove_destination: true
is not given.
Related: FileUtils.ln
(has different options).
Creates hard links; returns nil
.
Arguments src
and dest
should be interpretable as paths.
If src
is the path to a file and dest
does not exist, creates a hard link at dest
pointing to src
:
FileUtils.touch('src0.txt') File.exist?('dest0.txt') # => false FileUtils.link_entry('src0.txt', 'dest0.txt') File.file?('dest0.txt') # => true
If src
is the path to a directory and dest
does not exist, recursively creates hard links at dest
pointing to paths in src
:
FileUtils.mkdir_p(['src1/dir0', 'src1/dir1']) src_file_paths = [ 'src1/dir0/t0.txt', 'src1/dir0/t1.txt', 'src1/dir1/t2.txt', 'src1/dir1/t3.txt', ] FileUtils.touch(src_file_paths) File.directory?('dest1') # => true FileUtils.link_entry('src1', 'dest1') File.file?('dest1/dir0/t0.txt') # => true File.file?('dest1/dir0/t1.txt') # => true File.file?('dest1/dir1/t2.txt') # => true File.file?('dest1/dir1/t3.txt') # => true
Keyword arguments:
dereference_root: true
- dereferences src
if it is a symbolic link.
remove_destination: true
- removes dest
before creating links.
Raises an exception if dest
is the path to an existing file or directory and keyword argument remove_destination: true
is not given.
Related: FileUtils.ln
(has different options).
Takes a hash as its argument. The key is a symbol or an array of symbols. These symbols correspond to method names, instance variable names, or constant names (see def_delegator
). The value is the accessor to which the methods will be delegated.
Returns whether or not the given entry point func
can be found within lib
. If func
is nil
, the main()
entry point is used by default. If found, it adds the library to list of libraries to be used when linking your extension.
If headers
are provided, it will include those header files as the header files it looks in when searching for func
.
The real name of the library to be linked can be altered by --with-FOOlib
configuration option.
Returns whether or not the entry point func
can be found within the library lib
in one of the paths
specified, where paths
is an array of strings. If func
is nil
, then the main()
function is used as the entry point.
If lib
is found, then the path it was found on is added to the list of library paths searched and linked against.
Returns a hash of the defined schemes:
URI.scheme_list # => {"MAILTO"=>URI::MailTo, "LDAPS"=>URI::LDAPS, "WS"=>URI::WS, "HTTP"=>URI::HTTP, "HTTPS"=>URI::HTTPS, "LDAP"=>URI::LDAP, "FILE"=>URI::File, "FTP"=>URI::FTP}
Related: URI.register_scheme
.
Basically a wrapper for Process.spawn
that:
Creates a child process for each of the given cmds
by calling Process.spawn
.
Pipes the stdout
from each child to the stdin
of the next child, or, for the first child, from the caller’s stdin
, or, for the last child, to the caller’s stdout
.
The method does not wait for child processes to exit, so the caller must do so.
With no block given, returns a 3-element array containing:
The stdin
stream of the first child process.
The stdout
stream of the last child process.
An array of the wait threads for all of the child processes.
Example:
first_stdin, last_stdout, wait_threads = Open3.pipeline_rw('sort', 'cat -n') # => [#<IO:fd 20>, #<IO:fd 21>, [#<Process::Waiter:0x000055e8de29ab40 sleep>, #<Process::Waiter:0x000055e8de29a690 sleep>]] first_stdin.puts("foo\nbar\nbaz") first_stdin.close # Send EOF to sort. puts last_stdout.read wait_threads.each do |wait_thread| wait_thread.join end
Output:
1 bar 2 baz 3 foo
With a block given, calls the block with the stdin
stream of the first child, the stdout
stream of the last child, and an array of the wait processes:
Open3.pipeline_rw('sort', 'cat -n') do |first_stdin, last_stdout, wait_threads| first_stdin.puts "foo\nbar\nbaz" first_stdin.close # send EOF to sort. puts last_stdout.read wait_threads.each do |wait_thread| wait_thread.join end end
Output:
1 bar 2 baz 3 foo
Like Process.spawn
, this method has potential security vulnerabilities if called with untrusted input; see Command Injection.
If the first argument is a hash, it becomes leading argument env
in each call to Process.spawn
; see Execution Environment.
If the last argument is a hash, it becomes trailing argument options
in each call to Process.spawn
; see Execution Options.
Each remaining argument in cmds
is one of:
A command_line
: a string that begins with a shell reserved word or special built-in, or contains one or more metacharacters.
An exe_path
: the string path to an executable to be called.
An array containing a command_line
or an exe_path
, along with zero or more string arguments for the command.
Basically a wrapper for Process.spawn
that:
Creates a child process for each of the given cmds
by calling Process.spawn
.
Pipes the stdout
from each child to the stdin
of the next child, or, for the first child, from the caller’s stdin
, or, for the last child, to the caller’s stdout
.
The method does not wait for child processes to exit, so the caller must do so.
With no block given, returns a 3-element array containing:
The stdin
stream of the first child process.
The stdout
stream of the last child process.
An array of the wait threads for all of the child processes.
Example:
first_stdin, last_stdout, wait_threads = Open3.pipeline_rw('sort', 'cat -n') # => [#<IO:fd 20>, #<IO:fd 21>, [#<Process::Waiter:0x000055e8de29ab40 sleep>, #<Process::Waiter:0x000055e8de29a690 sleep>]] first_stdin.puts("foo\nbar\nbaz") first_stdin.close # Send EOF to sort. puts last_stdout.read wait_threads.each do |wait_thread| wait_thread.join end
Output:
1 bar 2 baz 3 foo
With a block given, calls the block with the stdin
stream of the first child, the stdout
stream of the last child, and an array of the wait processes:
Open3.pipeline_rw('sort', 'cat -n') do |first_stdin, last_stdout, wait_threads| first_stdin.puts "foo\nbar\nbaz" first_stdin.close # send EOF to sort. puts last_stdout.read wait_threads.each do |wait_thread| wait_thread.join end end
Output:
1 bar 2 baz 3 foo
Like Process.spawn
, this method has potential security vulnerabilities if called with untrusted input; see Command Injection.
If the first argument is a hash, it becomes leading argument env
in each call to Process.spawn
; see Execution Environment.
If the last argument is a hash, it becomes trailing argument options
in each call to Process.spawn
; see Execution Options.
Each remaining argument in cmds
is one of:
A command_line
: a string that begins with a shell reserved word or special built-in, or contains one or more metacharacters.
An exe_path
: the string path to an executable to be called.
An array containing a command_line
or an exe_path
, along with zero or more string arguments for the command.