Pre-defined variables¶ ↑
- $!
-
The exception information message set by 'raise'.
- $@
-
Array of backtrace of the last exception thrown.
- $&
-
The string matched by the last successful match.
- $`
-
The string to the left of the last successful match.
- $'
-
The string to the right of the last successful match.
- $+
-
The highest group matched by the last successful match.
- $1
-
The Nth group of the last successful match. May be > 1.
- $~
-
The information about the last match in the current scope.
- $=
-
The flag for case insensitive, nil by default.
- $/
-
The input record separator, newline by default.
- $\
-
The output record separator for the print and IO#write. Default is nil.
- $,
-
The output field separator for the print and Array#join.
- $;
-
The default separator for String#split.
- $.
-
The current input line number of the last file that was read.
- $<
-
The virtual concatenation file of the files given on command line (or from $stdin if no files were given).
- $>
-
The default output for print, printf. $stdout by default.
- $_
-
The last input line of string by gets or readline.
- $0
-
Contains the name of the script being executed. May be assignable.
- $*
-
Command line arguments given for the script sans args.
- $$
-
The process number of the Ruby running this script.
- $?
-
The status of the last executed child process. This value is thread-local.
- $:
-
Load path for scripts and binary modules by load or require.
- $“
-
The array contains the module names loaded by require.
- $DEBUG
-
The debug flag, which is set by the -d switch. Enabling debug output prints each exception raised to $stderr (but not its backtrace). Setting this to a true value enables debug output as if -d were given on the command line. Setting this to a false value disables debug output.
- $FILENAME
-
Current input file from $<. Same as $<.filename.
- $LOAD_PATH
-
The alias to the $:.
- $stderr
-
The current standard error output.
- $stdin
-
The current standard input.
- $stdout
-
The current standard output.
- $VERBOSE
-
The verbose flag, which is set by the -w or -v switch. Setting this to a true value enables warnings as if -w or -v were given on the command line. Setting this to nil disables warnings, including from Kernel#warn.
- $-0
-
The alias to $/.
- $-a
-
True if option -a is set. Read-only variable.
- $-d
-
The alias of $DEBUG. See $DEBUG above for further discussion.
- $-F
-
The alias to $;.
- $-i
-
In in-place-edit mode, this variable holds the extension, otherwise nil.
- $-I
-
The alias to $:.
- $-l
-
True if option -l is set. Read-only variable.
- $-p
-
True if option -p is set. Read-only variable.
- $-v
-
An alias of $VERBOSE. See $VERBOSE above for further discussion.
- $-w
-
An alias of $VERBOSE. See $VERBOSE above for further discussion.
Pre-defined global constants¶ ↑
- TRUE
-
The typical true value.
- FALSE
-
The false itself.
- NIL
-
The nil itself.
- STDIN
-
The standard input. The default value for $stdin.
- STDOUT
-
The standard output. The default value for $stdout.
- STDERR
-
The standard error output. The default value for $stderr.
- ENV
-
The hash contains current environment variables.
- ARGF
-
The alias to the $<.
- ARGV
-
The alias to the $*.
- DATA
-
The file object of the script, pointing just after __END__.
- RUBY_VERSION
-
The ruby version string (VERSION was deprecated).
- RUBY_RELEASE_DATE
-
The release date string.
- RUBY_PLATFORM
-
The platform identifier.