# -*- mode: rdoc; coding: utf-8; fill-column: 74; -*- == 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. $LOADED_FEATURES:: The alias to the $". $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.