Ruby Pocket Reference

Running Ruby

Test to see whether Ruby is running on your computer by typing the following at a shell or command prompt:

ruby --version

An affirmative response will look similar to this (this example is for version 1.8.6 running on Mac OS X):

ruby 1.8.6 (2007-03-13 patchlevel 0) [powerpc-darwin8.9.0]

You can install Ruby on any of the major platforms. For Ruby file archives and installation instructions, see http://www.ruby-lang.org/en/downloads.

Running the Ruby Interpreter

Usage:

ruby [switches] [--] [program filename] [arguments]

Switches (or command-line options):

-0[octal]

Specify a record separator (\0 if no argument).

-a

Autosplit mode with -n or -p (splits $_ into $F).

-c

Check syntax only.

-Cdirectory

cd to directory before executing your script or program.

-d

Set debugging flags (set predefined variable $DEBUG to true).

-e 'command'

Execute one line of script. Several -es allowed. Omit [program filename].

-Fpattern

split( ) pattern for autosplit (-a).

-i[extension]

Edit ARGV files in place (make backup if extension supplied).

-Idirectory

Specify $LOAD_PATH (predefined variable) directory; may be used more than once.

-Kkcode

Specify the character set. See Table 16.

-l

Enable line-ending processing.

-n

Assume 'while gets( ); ... end' loop around your script.

-p

Assume loop like -n but print line also like sed.

-rlibrary

Require the library before executing your script.

-s

Enable some switch parsing for switches after script name.

-S

Look for the script using PATH environment variable.

-T[level]

Turn on tainting checks. ...