The Ruby Programming Language

Invoking the Ruby Interpreter

The standard C-based Ruby implementation is invoked from the command line like this:

ruby [options] [--] program [arguments]

options is zero or more command-line arguments that affect the operation of the interpreter. The legal arguments are described shortly.

program is the name of the file that holds the Ruby program to be run. If the name of the program begins with a hyphen, precede it with -- to force it to be treated as a program name rather than as an option. If you use a single hyphen as the program name, or omit program and arguments altogether, the interpreter will read program text from standard input.

Finally, arguments is any number of additional tokens on the command line. These tokens become the elements of the ARGV array.

The subsections that follow describe the options supported by the standard C-based Ruby implementation. Note that you may set the RUBYOPT environment variable to include any of the -W, -w, -v, -d, -I, -r, -K, -E, and -T options. These will automatically be applied to every invocation of the interpreter, as if they were specified on the command line, unless the command line includes --disable-rubyopt.

Common Options

The following options are probably the most commonly used. Most Ruby implementations can be expected to support these options or to provide a work-alike alternative:

-w

This option enables warnings about deprecated or problematic code and sets $VERBOSE to true. Many Ruby programmers use this option routinely to ensure ...