зеркало из https://github.com/github/ruby.git
423 строки
8.5 KiB
Plaintext
423 строки
8.5 KiB
Plaintext
= Pre-Defined Global Variables
|
|
|
|
Some of the pre-defined global variables have synonyms
|
|
that are available via module Engish.
|
|
For each of those, the \English synonym is given.
|
|
|
|
To use the module:
|
|
|
|
require 'English'
|
|
|
|
== Exceptions
|
|
|
|
=== <tt>$!</tt> (\Exception)
|
|
|
|
Contains the Exception object set by Kernel#raise:
|
|
|
|
begin
|
|
raise RuntimeError.new('Boo!')
|
|
rescue RuntimeError
|
|
p $!
|
|
end
|
|
|
|
Output:
|
|
|
|
#<RuntimeError: Boo!>
|
|
|
|
English - <tt>$ERROR_INFO</tt>
|
|
|
|
=== <tt>$@</tt> (Backtrace)
|
|
|
|
Same as <tt>$!.backtrace</tt>;
|
|
returns an array of backtrace positions:
|
|
|
|
begin
|
|
raise RuntimeError.new('Boo!')
|
|
rescue RuntimeError
|
|
pp $@.take(4)
|
|
end
|
|
|
|
Output:
|
|
|
|
["(irb):338:in `<top (required)>'",
|
|
"/snap/ruby/317/lib/ruby/3.2.0/irb/workspace.rb:119:in `eval'",
|
|
"/snap/ruby/317/lib/ruby/3.2.0/irb/workspace.rb:119:in `evaluate'",
|
|
"/snap/ruby/317/lib/ruby/3.2.0/irb/context.rb:502:in `evaluate'"]
|
|
|
|
English - <tt>$ERROR_POSITION</tt>.
|
|
|
|
== Pattern Matching
|
|
|
|
These global variables store information about the most recent
|
|
successful match in the current scope.
|
|
|
|
For details and examples,
|
|
see {Regexp Global Variables}[rdoc-ref:Regexp@Global+Variables].
|
|
|
|
=== <tt>$~</tt> (\MatchData)
|
|
|
|
MatchData object created from the match;
|
|
thread-local and frame-local.
|
|
|
|
English - <tt>$LAST_MATCH_INFO</tt>.
|
|
|
|
=== <tt>$&</tt> (Matched Substring)
|
|
|
|
The matched string.
|
|
|
|
English - <tt>$MATCH</tt>.
|
|
|
|
=== <tt>$`</tt> (Pre-Match Substring)
|
|
|
|
The string to the left of the match.
|
|
|
|
English - <tt>$PREMATCH</tt>.
|
|
|
|
=== <tt>$'</tt> (Post-Match Substring)
|
|
|
|
The string to the right of the match.
|
|
|
|
English - <tt>$POSTMATCH</tt>.
|
|
|
|
=== <tt>$+</tt> (Last Matched Group)
|
|
|
|
The last group matched.
|
|
|
|
English - <tt>$LAST_PAREN_MATCH</tt>.
|
|
|
|
=== <tt>$1</tt>, <tt>$2</tt>, \Etc. (Matched Group)
|
|
|
|
For <tt>$_n_</tt> the _nth_ group of the match.
|
|
|
|
No \English.
|
|
|
|
== Separators
|
|
|
|
=== <tt>$/</tt> (Input Record Separator)
|
|
|
|
An input record separator, initially newline.
|
|
|
|
English - <tt>$INPUT_RECORD_SEPARATOR</tt>, <tt>$RS</tt>.
|
|
|
|
Aliased as <tt>$-0</tt>.
|
|
|
|
=== <tt>$;</tt> (Input Field Separator)
|
|
|
|
An input field separator, initially +nil+.
|
|
|
|
English - <tt>$FIELD_SEPARATOR</tt>, <tt>$FS</tt>.
|
|
|
|
Aliased as <tt>$-F</tt>.
|
|
|
|
=== <tt>$\\</tt> (Output Record Separator)
|
|
|
|
An output record separator, initially +nil+.
|
|
|
|
English - <tt>$OUTPUT_RECORD_SEPARATOR</tt>, <tt>$ORS</tt>.
|
|
|
|
== Streams
|
|
|
|
=== <tt>$stdin</tt> (Standard Input)
|
|
|
|
The current standard input stream; initially:
|
|
|
|
$stdin # => #<IO:<STDIN>>
|
|
|
|
=== <tt>$stdout</tt> (Standard Output)
|
|
|
|
The current standard output stream; initially:
|
|
|
|
$stdout # => #<IO:<STDOUT>>
|
|
|
|
=== <tt>$stderr</tt> (Standard Error)
|
|
|
|
The current standard error stream; initially:
|
|
|
|
$stderr # => #<IO:<STDERR>>
|
|
|
|
=== <tt>$<</tt> (\ARGF or $stdin)
|
|
|
|
Points to stream ARGF if not empty, else to stream $stdin; read-only.
|
|
|
|
English - <tt>$DEFAULT_INPUT</tt>.
|
|
|
|
=== <tt>$></tt> (Default Standard Output)
|
|
|
|
An output stream, initially <tt>$stdout</tt>.
|
|
|
|
English - <tt>$DEFAULT_OUTPUT
|
|
|
|
=== <tt>$.</tt> (Input Position)
|
|
|
|
The input position (line number) in the most recently read stream.
|
|
|
|
English - <tt>$INPUT_LINE_NUMBER</tt>, <tt>$NR</tt>
|
|
|
|
=== <tt>$_</tt> (Last Read Line)
|
|
|
|
The line (string) from the most recently read stream.
|
|
|
|
English - <tt>$LAST_READ_LINE</tt>.
|
|
|
|
== Processes
|
|
|
|
=== <tt>$0</tt>
|
|
|
|
Initially, contains the name of the script being executed;
|
|
may be reassigned.
|
|
|
|
=== <tt>$*</tt> (\ARGV)
|
|
|
|
Points to ARGV.
|
|
|
|
English - <tt>$ARGV</tt>.
|
|
|
|
=== <tt>$$</tt> (Process ID)
|
|
|
|
The process ID of the current process. Same as Process.pid.
|
|
|
|
English - <tt>$PROCESS_ID</tt>, <tt>$PID</tt>.
|
|
|
|
=== <tt>$?</tt> (Child Status)
|
|
|
|
Initially +nil+, otherwise the Process::Status object
|
|
created for the most-recently exited child process;
|
|
thread-local.
|
|
|
|
English - <tt>$CHILD_STATUS</tt>.
|
|
|
|
=== <tt>$LOAD_PATH</tt> (Load Path)
|
|
|
|
Contains the array of paths to be searched
|
|
by Kernel#load and Kernel#require.
|
|
|
|
Singleton method <tt>$LOAD_PATH.resolve_feature_path(feature)</tt>
|
|
returns:
|
|
|
|
- <tt>[:rb, _path_]</tt>, where +path+ is the path to the Ruby file
|
|
to be loaded for the given +feature+.
|
|
- <tt>[:so+ _path_]</tt>, where +path+ is the path to the shared object file
|
|
to be loaded for the given +feature+.
|
|
- +nil+ if there is no such +feature+ and +path+.
|
|
|
|
Examples:
|
|
|
|
$LOAD_PATH.resolve_feature_path('timeout')
|
|
# => [:rb, "/snap/ruby/317/lib/ruby/3.2.0/timeout.rb"]
|
|
$LOAD_PATH.resolve_feature_path('date_core')
|
|
# => [:so, "/snap/ruby/317/lib/ruby/3.2.0/x86_64-linux/date_core.so"]
|
|
$LOAD_PATH.resolve_feature_path('foo')
|
|
# => nil
|
|
|
|
Aliased as <tt>$:</tt> and <tt>$-I</tt>.
|
|
|
|
=== <tt>$LOADED_FEATURES</tt>
|
|
|
|
Contains an array of the paths to the loaded files:
|
|
|
|
$LOADED_FEATURES.take(10)
|
|
# =>
|
|
["enumerator.so",
|
|
"thread.rb",
|
|
"fiber.so",
|
|
"rational.so",
|
|
"complex.so",
|
|
"ruby2_keywords.rb",
|
|
"/snap/ruby/317/lib/ruby/3.2.0/x86_64-linux/enc/encdb.so",
|
|
"/snap/ruby/317/lib/ruby/3.2.0/x86_64-linux/enc/trans/transdb.so",
|
|
"/snap/ruby/317/lib/ruby/3.2.0/x86_64-linux/rbconfig.rb",
|
|
"/snap/ruby/317/lib/ruby/3.2.0/rubygems/compatibility.rb"]
|
|
|
|
Aliased as <tt>$"</tt>.
|
|
|
|
== Debugging
|
|
|
|
=== <tt>$FILENAME</tt>
|
|
|
|
The value returned by method ARGF.filename.
|
|
|
|
=== <tt>$DEBUG</tt>
|
|
|
|
Initially +true+ if command-line option <tt>-d</tt> or <tt>--debug</tt> is given,
|
|
otherwise initially +false+;
|
|
may be set to either value in the running program.
|
|
|
|
When +true+, prints each raised exception to <tt>$stderr</tt>.
|
|
|
|
Aliased as <tt>$-d</tt>.
|
|
|
|
=== <tt>$VERBOSE</tt>
|
|
|
|
Initially +true+ if command-line option <tt>-v</tt> or <tt>-w</tt> is given,
|
|
otherwise initially +false+;
|
|
may be set to either value, or to +nil+, in the running program.
|
|
|
|
When +true+, enables Ruby warnings.
|
|
|
|
When +nil+, disables warnings, including those from Kernel#warn.
|
|
|
|
Aliased as <tt>$-v</tt> and <tt>$-w</tt>.
|
|
|
|
== Other Variables
|
|
|
|
=== <tt>$-a</tt>
|
|
|
|
Whether command-line option <tt>-a</tt> was given; read-only.
|
|
|
|
=== <tt>$-i</tt>
|
|
|
|
Contains the extension given with command-line option <tt>-i</tt>,
|
|
or +nil+ if none.
|
|
|
|
An alias of ARGF.inplace_mode.
|
|
|
|
=== <tt>$-l</tt>
|
|
|
|
Whether command-line option <tt>-l</tt> was set; read-only.
|
|
|
|
=== <tt>$-p</tt>
|
|
|
|
Whether command-line option <tt>-p</tt> was given; read-only.
|
|
|
|
== Deprecated
|
|
|
|
=== <tt>$=</tt>
|
|
|
|
=== <tt>$,</tt>
|
|
|
|
= Pre-Defined Global Constants
|
|
|
|
= Streams
|
|
|
|
=== <tt>STDIN</tt>
|
|
|
|
The standard input stream (the default value for <tt>$stdin</tt>):
|
|
|
|
STDIN # => #<IO:<STDIN>>
|
|
|
|
=== <tt>STDOUT</tt>
|
|
|
|
The standard output stream (the default value for <tt>$stdout</tt>):
|
|
|
|
STDOUT # => #<IO:<STDOUT>>
|
|
|
|
=== <tt>STDERR</tt>
|
|
|
|
The standard error stream (the default value for <tt>$stderr</tt>):
|
|
|
|
STDERR # => #<IO:<STDERR>>
|
|
|
|
== Environment
|
|
|
|
=== ENV
|
|
|
|
A hash of the contains current environment variables names and values:
|
|
|
|
ENV.take(5)
|
|
# =>
|
|
[["COLORTERM", "truecolor"],
|
|
["DBUS_SESSION_BUS_ADDRESS", "unix:path=/run/user/1000/bus"],
|
|
["DESKTOP_SESSION", "ubuntu"],
|
|
["DISPLAY", ":0"],
|
|
["GDMSESSION", "ubuntu"]]
|
|
|
|
=== ARGF
|
|
|
|
The virtual concatenation of the files given on the command line, or from
|
|
<tt>$stdin</tt> if no files were given, <tt>"-"</tt> is given, or after
|
|
all files have been read.
|
|
|
|
=== <tt>ARGV</tt>
|
|
|
|
An array of the given command-line arguments.
|
|
|
|
=== <tt>TOPLEVEL_BINDING</tt>
|
|
|
|
The Binding of the top level scope:
|
|
|
|
TOPLEVEL_BINDING # => #<Binding:0x00007f58da0da7c0>
|
|
|
|
=== <tt>RUBY_VERSION</tt>
|
|
|
|
The Ruby version:
|
|
|
|
RUBY_VERSION # => "3.2.2"
|
|
|
|
=== <tt>RUBY_RELEASE_DATE</tt>
|
|
|
|
The release date string:
|
|
|
|
RUBY_RELEASE_DATE # => "2023-03-30"
|
|
|
|
=== <tt>RUBY_PLATFORM</tt>
|
|
|
|
The platform identifier:
|
|
|
|
RUBY_PLATFORM # => "x86_64-linux"
|
|
|
|
=== <tt>RUBY_PATCHLEVEL</tt>
|
|
|
|
The integer patch level for this Ruby:
|
|
|
|
RUBY_PATCHLEVEL # => 53
|
|
|
|
For a development build the patch level will be -1.
|
|
|
|
=== <tt>RUBY_REVISION</tt>
|
|
|
|
The git commit hash for this Ruby:
|
|
|
|
RUBY_REVISION # => "e51014f9c05aa65cbf203442d37fef7c12390015"
|
|
|
|
=== <tt>RUBY_COPYRIGHT</tt>
|
|
|
|
The copyright string:
|
|
|
|
RUBY_COPYRIGHT
|
|
# => "ruby - Copyright (C) 1993-2023 Yukihiro Matsumoto"
|
|
|
|
=== <tt>RUBY_ENGINE</tt>
|
|
|
|
The name of the Ruby implementation:
|
|
|
|
RUBY_ENGINE # => "ruby"
|
|
|
|
=== <tt>RUBY_ENGINE_VERSION</tt>
|
|
|
|
The version of the Ruby implementation:
|
|
|
|
RUBY_ENGINE_VERSION # => "3.2.2"
|
|
|
|
=== <tt>RUBY_DESCRIPTION</tt>
|
|
|
|
The description of the Ruby implementation:
|
|
|
|
RUBY_DESCRIPTION
|
|
# => "ruby 3.2.2 (2023-03-30 revision e51014f9c0) [x86_64-linux]"
|
|
|
|
== Embedded \Data
|
|
|
|
=== <tt>DATA</tt>
|
|
|
|
Defined if and only if the program has this line:
|
|
|
|
__END__
|
|
|
|
When defined, <tt>DATA</tt> is a File object
|
|
containing the lines following the <tt>__END__</tt>,
|
|
positioned at the first of those lines:
|
|
|
|
p DATA
|
|
DATA.each_line { |line| p line }
|
|
__END__
|
|
Foo
|
|
Bar
|
|
Baz
|
|
|
|
Output:
|
|
|
|
#<File:t.rb>
|
|
"Foo\n"
|
|
"Bar\n"
|
|
"Baz\n"
|