Top Level Namespace

Defined Under Namespace

Modules: Comparable, Enumerable, Errno, FileTest, GC, Kernel, Marshal, Math, ObjectSpace, Process, Signal, UnicodeNormalize, Warning Classes: ArgumentError, Array, BasicObject, Binding, Class, ClosedQueueError, Complex, Continuation, Data, Dir, ENV, EOFError, Encoding, EncodingError, Enumerator, Exception, FalseClass, Fiber, FiberError, File, Float, FloatDomainError, FrozenError, Hash, IO, IOError, IndexError, Integer, Interrupt, KeyError, LoadError, LocalJumpError, MatchData, Method, Module, NameError, NilClass, NoMatchingPatternError, NoMatchingPatternKeyError, NoMemoryError, NoMethodError, NotImplementedError, Numeric, Object, Proc, Ractor, Random, Range, RangeError, Rational, Refinement, Regexp, RegexpError, RubyVM, RuntimeError, ScriptError, SecurityError, SignalException, StandardError, StopIteration, String, Struct, Symbol, SyntaxError, SystemCallError, SystemExit, SystemStackError, Thread, ThreadError, ThreadGroup, Time, TracePoint, TrueClass, TypeError, UnboundMethod, UncaughtThrowError, ZeroDivisionError, fatal

Constant Summary

STDIN =

Holds the original stdin

rb_stdin

STDOUT =

Holds the original stdout

rb_stdout

STDERR =

Holds the original stderr

rb_stderr

ARGF =

$ ruby argf.rb –verbose file1 file2

ARGV  #=> ["--verbose", "file1", "file2"]
option = ARGV.shift #=> "--verbose"
ARGV  #=> ["file1", "file2"]

You can now use ARGF to work with a concatenation of each of these named files. For instance, ARGF.read will return the contents of file1 followed by the contents of file2.

After a file in ARGV has been read ARGF removes it from the Array. Thus, after all files have been read ARGV will be empty.

You can manipulate ARGV yourself to control what ARGF operates on. If you remove a file from ARGV, it is ignored by ARGF; if you add files to ARGV, they are treated as if they were named on the command line. For example:

ARGV.replace ["file1"]
ARGF.readlines # Returns the contents of file1 as an Array
ARGV           #=> []
ARGV.replace ["file2", "file3"]
ARGF.read      # Returns the contents of file2 and file3

If ARGV is empty, ARGF acts as if it contained "-" that makes ARGF read from STDIN, i.e. the data piped or typed to your script. For example:

$ echo "glark" | ruby -e 'p ARGF.read'
"glark\n"

$ echo Glark > file1
$ echo "glark" | ruby -e 'p ARGF.read' -- - file1
"glark\nGlark\n"

ARGF is a stream designed for use in scripts that process files given as
command-line arguments or passed in via STDIN.

The arguments passed to your script are stored in the +ARGV+ Array, one
argument per element. ARGF assumes that any arguments that aren't
filenames have been removed from +ARGV+. For example

TOPLEVEL_BINDING =

The Binding of the top level scope

rb_binding_new()

ARGV =

ARGV contains the command line arguments used to run ruby.

A library like OptionParser can be used to process command-line arguments.

rb_argv

RUBY_VERSION =

MKSTR(version)

/* MKSTR(version) */ version

RUBY_RELEASE_DATE =

The date this ruby was released

MKSTR(release_date)

RUBY_PLATFORM =

The platform for this ruby

MKSTR(platform)

RUBY_PATCHLEVEL =

The patchlevel for this ruby. If this is a development build of ruby the patchlevel will be -1

MKINT(patchlevel)

RUBY_REVISION =

The GIT commit hash for this ruby.

MKSTR(revision)

RUBY_COPYRIGHT =

The copyright string for ruby

MKSTR(copyright)

RUBY_ENGINE =

MKSTR(engine)

/* MKSTR(engine) */ ruby_engine_name

RUBY_ENGINE_VERSION =

MKSTR(version)

/* MKSTR(version) */ version

RUBY_DESCRIPTION =

MKSTR(description)

/* MKSTR(description) */ description