The argument string is passed to the block in which it should be converted to the desired class. ARGF will interpret all elements of the ARGV array as filenames and when read will produce a concatenation of the contents of these files. The directories will be created as necessary. A program can have many command-line arguments that identify sources or destinations of information, or that alter the operation of the program. Writing a Shell in 25 Lines of Ruby CodeJuly 12, 2016. When optional into keyword argument is provided, the parsed option values are stored there via []= method (so it can be Hash, or OpenStruct, or other similar object). This is the most complex and tedious method, but it pays off on the command line. Luckily, Ruby is smart enough to know that the argument "foo" is intended for your program, not for Ruby itself. Once there, you can list files, using the dir  Ruby is generally run from the command line in the following way − $ ruby [ options ] [.] 3 The Rails Advanced Command Line. $ ruby -e 'puts "Hello, world."' More About Methods, Variable-Length Argument Lists. size == 1 and Array === argv [ 0 ] permute! Separated by spaces, each word or string will be passed as a separate argument to the Ruby program. But Ruby is far more than a web language. To mark the file as executable, run the command chmod +x test.rb. On the positive side, it's really clean. Let's start with an example of code that parses the command line. The -e argument tells Ruby to run the provided code and exit. #!/usr/bin/ruby puts $0 puts $* The $0 global variable contains the name of the script being executed. So your program will see one argument, "foo". Command line argument is a parameter supplied to the program when it is invoked. [ programfile ] [ arguments. For example: psql --help How to Use the Command Line to Run Ruby Scripts, Open a command line window and navigate to your Ruby scripts directory using the cd command. Listed here are some tricks up Rails’ sleeve. Reading command-line arguments. Use the %x  Execute shell commands. Unlike some other languages, Ruby does not include the name of the script being executed as an argument. Ruby is strongly identified with Rails and web development. Separated by spaces, each word or string will be passed as a separate argument to the Ruby program. So your program will see one argument, "foo". Command line arguments can be taken from the users with the help of 'ARGV' keyword. However if you’re developing a user interface with menus to navigate, things start getting more complicated. You only have to write the command-line switch, its arguments, the code to run when it's encountered, and the command-line switch description once in your script. Method #4: Ruby OptionParser. Options.py contains a variety of options that can be set on the command line. Within the initialization file you may run any arbitrary Ruby code. When written inside your Ruby program, ARGV will take take a command line command that looks like this:ruby testing_argv.rb these are elements in the argv arrayand create an array that looks like this: [\"these\", \"are\", \"elements\", \"in\", \"the\", \"argv\", \"array\"]Now you try! Ruby is strongly identified with Rails and web development. Let's start by executing a Ruby command. ARGVstands for ARGument Vector — as a vector is a one-dimensional array. Today I have the pleasure of dawning reality on you. Global variables in Ruby begin with the $ character. CLASP.Ruby. The task looks like this: How to Run System Commands From Ruby, Related. This is the most complex and tedious method, but it pays off on the command line. ARGV is an Array variable which holds, as strings, each argument passed by the shell. You can email the site owner to let them know you were blocked. The goal of this article is to show you how you can create your command line application using the Ruby programming language and make it available via Homebrew, so anyone can install it quickly and use in seconds. When a block is given, each non-option argument is yielded. The rspec command comes with several options you can use to customize RSpec's behavior, including output formats, filtering examples, etc. Command line. Splitting the last argument into positional and keyword parameters is deprecated In most cases, you can avoid the incompatibility by adding the double splat o… On the command-line, any text following the name of the script is considered a command-line argument. The RubyGems environment can be controlled through command line arguments, gemrc files, environment variables and built-in defaults. If no digits given, the null character is the separator. bundle exec ruby -I c:\openstudio-2.4.0\Ruby\ c:\openstudio-2.4.0\Ruby\openstudio_cli.rb run -w in.osw If your arguments are few in number and predictable in nature, then it's a nice means of accepting arguments. We can access the elements of this array, just as any other array: ARGV … If you’re developing a one-off command-line tool that simply takes an input or source and processes/formats it and spits out the information, then your work is rather simple. The first argument that gets passed to the script happens. Ruby is a really clear and expressive language, but we developers sure know how to make a  Ruby FAQ: How do I create a variable length argument list in a Ruby method? This website is using a security service to protect itself from online attacks. ARGVstands for ARGument Vector — as a vector is a one-dimensional array. The question though, how can the Ruby program know what was given on the command line? In Ruby 3.0, positional arguments and keyword arguments will be separated. Command line arguments. Ruby file accepts from command prompt in the form of array.Passing parametersruby input.rb TOI DH TimesNewAccessing parameters # input.rb p ARGV # => ["TOI", "DH", "TimesNew"] p ARGV[0] # => "TOI" p ARGV[1] # => "DH"Optparser : parses commandline options in more effective way using OptParser class.and we can access options as hashed parameters.Passing parametersruby… For instance, invoking Ruby as % ruby -w ptest "Hello World" a1 1.6180 yields an ARGV array containing ["Hello World", a1, 1.6180]. The first CLASP library was a C library with a C++ wrapper. If you’re developing a one-off command-line tool that simply takes an input or source and processes/formats it and spits out the information, then your work is rather simple. Instead, the version of the OpenStudio Ruby bindings loaded can be controlled using the -I Ruby command line option. jekyll new PATH --blank - Creates a new blank Jekyll site scaffold at specified path. A command-line argument or parameter is an item of information provided to a program when it is started. For example, ARGV[0] returns the first argument passed to the Ruby script. Ara T. Howard's Main is a nifty gem for creating command-line scripts. It will look at the next element on the command line, and extract information from it. dup if argv . To run the test.rb Ruby script, run the command ruby test.rb. As far as the OS is concerned, you're running a program called "ruby" and passing it two arguments. Performance & security by Cloudflare. Parses command line arguments argv in permutation mode and returns list of non-option arguments. bundle exec ruby -I c:\openstudio-2.4.0\Ruby\ c:\openstudio-2.4.0\Ruby\openstudio_cli.rb run -w in.osw Running command line commands within Ruby script, Yes. Sorting an array in Ruby. If no digits given, the null character is the separator. Ruby is generally run from the command line in the following way − $ ruby [ options ] [.] ARGV is a built-in array in Ruby for parsing command line arguments. There are three areas of concern to address when building a command-line application: the input, output, and everything in between. Now, to run the program, simply enter the command./test.rb. Unlike some other languages, Ruby does not include the name of the script being executed as an argument. Ruby has a rich set of tools for shell scripting and text processing. Line 4 defines main(), which is the entry point of a C program.Take good note of the parameters: argc is an integer representing the number of arguments of the program. Command line arguments are passed to the main() method. But Ruby is far more than a web language. When written inside your Ruby program, ARGV will take take a command line Ruby script arguments are passed to the Ruby program by the shell, the program that accepts commands (such as bash) on the terminal. CLASP stands for Command-Line Argument Sorting and Parsing. This is a good place to look to see if the option you want to change already has a command line parameter. Submitted by Hrithik Chandra Prasad, on September 02, 2019 . Reading command-line arguments. The command-line options for irb are listed in Table B.1 on page 518. The $* is another global variable. For a full list of options, run the rspec command with the --help flag: $ rspec --help Run with ruby. Ruby is generally run from the command line in the following way − $ ruby [ options ] [.] On the command-line, any text following the name of the script is considered a command-line argument. ARGF will interpret all elements of the ARGV array as filenames and when read will produce a concatenation of the contents of these files. You can also set any of the configuration values that correspond to command-line arguments as shown in Table B.2 on page 518. It contains command line arguments given for the current script. Typically, you'll run irb with no options, but if you want to run a script and watch the blow-by-blow description as it runs, you can provide the name of the Ruby script and any options for that script. If you must use OptionParser is DRY. The Ruby ARGV Constant. Parses command line arguments argv in order. As far as the OS is concerned, you're running a program called "ruby" and passing it two arguments. This status code can give you more information about why the command failed. ARGV is a built-in array in Ruby for parsing command line arguments. So if you ran ruby myscript.rb the ARGV object would be empty. A wrapper that provides a clean and easy way to parse arguments to your BASH scripts. It's not something you need all the time, but it sure is nice to have it when you need it. Your Ruby files will all have the.rb file extension. Command-line arguments are stored in a array called ARGV. E-Learning platform for Ruby and Ruby … -00 turns Ruby into paragraph mode. For a full list of options and their argument, see Build Command Options. Method #4: Ruby OptionParser. For dirt-simple argument … Optionally the name of a program to run. It is a synonym for the ARGV variable. It is mostly used when you need to control your program from outside. The -e argument tells Ruby to run the provided code and exit. Hello, world. nil if command execution fails (command not found) You can get the exit status code of the last external command that you ran with the $? Sorting an array in Ruby: Here, we are going to learn how to sort an array with command line arguments in Ruby programming language? What is Rake in Ruby & How to  Programs written for the command line tend to read STDIN and write to STDOUT. ... Python, Ruby or Jython), can be used to implement command-line interpreters and filters. Passing the keyword argument as the last hash parameter is deprecated, or 3. Here are some of the most common commands: jekyll new PATH - Creates a new Jekyll site with default gem-based theme at specified path. pat. In this program, we are introducing the concept of command line arguments. The Ruby standard library documentation describes it as such: ARGF is a stream designed for use in scripts that process files given as command-line arguments or passed in via STDIN. specifies the input record separator ($/) as an octal number. You’re going to learn about: The ARGV array; The OptParse library; The Thor gem; Let’s get started! The mandatory argument is a description of the list of valid switches. One thing I really dig about Ruby is that I can create methods and functions that support variable-length argument lists. Command-Line Argument Sorting and Parsing, for Ruby. Refactoring in Ruby: Smelly Parameters Lists, Refactoring in Ruby: Smelly Parameters Lists. Luckily, Ruby is smart enough to know that the argument "foo" is intended for your program, not for Ruby itself. Quick Guide to Command-Line Arguments in Ruby, In your Ruby programs, you can access any command-line arguments passed by the shell with the ARGV special variable. OptionParser will automatically generate help screens for you from this description, as well as infer everything about the argument from its description. Whether you invoke the Ruby interpreter manually with the Ruby command or run the Ruby script directly is up to you. Kernel#exec replaces the current process and runs the command: Call Windows .exe with arguments - Ruby, I found some direction on calling a .EXE here, such as: "C:\Documents and Settings\test.exe" However what if I need to run “test.exe /argument  Ruby script arguments are passed to the Ruby program by the shell, the program that accepts commands (such as bash) on the terminal. Named command line arguments in Ruby, There are a couple options. Command-line arguments are passed in through the ARGV object. ; argv is an array of pointers to characters containing the name of the program in the first element of the array, followed by the arguments of the program, if any, in the remaining elements of the array. OptionParser is a class that eases the parsing and the interpretation of command-line options. Like the number of CPUs, system clock, and many, many more. Ruby script arguments are passed to the Ruby program by the shell, the program that accepts commands (such as bash) on the terminal. On the command-line, any text following the name of the script is considered a command-line argument. -0777 makes Ruby read whole file at once as a single string, since there is no legal character with that value. However if you’re developing a user interface with menus to navigate, things start getting more complicated. The interpreter can be invoked with any of the following options to control the environment … Command-line applications usually take multiple options or ‘flags’. Let's start by executing a Ruby command. For a full list of options and their argument, see Build Command Options. Command line argument is an important concept in C programming. In this program, we are introducing the concept of command line arguments. Command-line applications usually take multiple options or ‘flags’. -0777 makes Ruby read whole file at once as a single string, since there is no legal character with that value. How to run a exe Asynchronously with two arguments in ruby , You can use Process.spawn and Process.wait2 : pid = Process.spawn 'your.exe', '--option' # Later pid, status = Process.wait2 pid. Passing the keyword argument as the last hash parameter is deprecated, or 3. It contains command line arguments given for the current script. In Ruby 3.0, positional arguments and keyword arguments will be separated. A Ruby command line consists of three parts: Options to the Ruby interpreter. The getopt library provides two different command line option parsers. This will set a file permission bit indicating that the file is a program and that it can be run. accept (t, pat, & block) You'll use this any time you want to access your application through a web browser. The syntax is fully described in g-comlin.ads (or accessible … For example: psql --help There are three areas of concern to address when building a command-line application: the input, output, and everything in between. Ruby maintains an array called ARGV with the values passed on the command line. Otherwise, at this point, I might prefer Method #2. The Ruby standard library documentation describes it as such: ARGF is a stream designed for use in scripts that process files given as command-line arguments or passed in via STDIN. They are meant as easier and more convenient replacements for the command line parsers that ship as part of the Ruby standard library. On the underside, bin/rails console uses IRB, so if you've ever used it, you'll be right at home. Syntax: int main(int argc, char *argv[]) Using the last argument as keyword parameters is deprecated, or 2. It lets you define short and long option names, handle flag variables, and set default values for optional arguments, all while aiming to be as minimal as possible: One line per argument definition. jekyll new PATH --blank - Creates a new blank Jekyll site scaffold at specified path. Generally, life is simpler if you just use the rspec command. It contains the full list of arguments inserted in the given command-line order. $ ./test.rb test1 test2 You may encounter a situation in which you need to pass an argument to a Ruby program but there's a space in the command. Command line argument defaults and some RubyGems defaults can be set in a ~/.gemrc file for individual users and a gemrc in the SYSTEM CONFIGURATION DIRECTORY for all users. a string entered on the command-line, and passed by the shell to execl() or execv().In Python, arguments are elements of sys.argv[1:] (sys.argv[0] is the name of the program being executed). Now when Food's nutrition changes its argument list, you don't have to change arguments in Bacon​  So Hey, ever bumped into the term Parameters in Ruby, Well parameters are often mistaken with the term arguments. Using the last argument as keyword parameters is deprecated, or 2. Cloudflare Ray ID: 6161103d8b2930aa The $* is another global variable. Unix shells also use the term “word”. Here are some of the most common commands: jekyll new PATH - Creates a new Jekyll site with default gem-based theme at specified path. If a gem is installed elsewhere in GEM_PATH the cleanup command won’t delete it. Copyright ©document.write(new Date().getFullYear()); All Rights Reserved, Compare two arrays of objects and return the difference javascript, How to load applicationcontext in junit test, Flutter plugin not installed; this adds flutter specific functionality vs code, How to pass data from view to controller in MVC, Call javascript function after page load complete. They are similar, in a not so…. CLASP stands for Command-Line Argument Sorting and Parsing. Terminology¶ argument. Other switches may follow the digits. You’re going to learn about: The ARGV array; The OptParse library; The Thor gem; Let’s get started! The directories will be created as necessary. There are a number of different ways to run shell commands from Ruby. Global variables in Ruby begin with the $ character. If you wish to skip some files or components from being generated, you can append the following arguments to your rails new command: 1.2 bin/rails server The bin/rails server command launches a web server named Puma which comes bundled with Rails. The article consists of two main parts: building the command line application and making it available via Homebrew. For dirt-simple argument … Returns the … It is a synonym for the ARGV variable. CLASP.Ruby. $ ruby -e 'puts "Hello, world."' Table of Contents. Once there, you can list files, using the dir command on Windows or the ls command on Linux or OS X. So if you ran ruby myscript.rb the ARGV object would be empty. Usage See sample_head.sh for a demonstration of optparse 1. It contains the full list of arguments inserted in the given command-line order. [ programfile ] [ arguments, Ruby's Powerful Method Arguments & How To Use Them Correctly, Ruby is very flexible when it comes to method arguments. Ruby has a rich set of tools for shell scripting and text processing. Command-Line Argument Sorting and Parsing, for Ruby. Sorting an array in Ruby: Here, we are going to learn how to sort an array with command line arguments in Ruby programming language? The exec command. OptionParser, in the Standard Library, is one of the most popular. 3.1 Rails with Databases and SCM There are many ways to build a command-line application & in this article we are going to focus on three of them. #!/usr/bin/ruby puts $0 puts $* The $0 global variable contains the name of the script being executed. What is Shell Expansion? The task looks like this: It's a global variable, so you can access it … The action you just performed triggered the security solution. -00 turns Ruby into paragraph mode. When you run an external command with system you’ll get the “shell expansion” effect. Hello, world. Ruby 2.7 will warn for behaviors that will change in Ruby 3.0. Ruby 2.7 will warn for behaviors that will change in Ruby 3.0. If your arguments are few in number and predictable in nature, then it's a nice means of accepting arguments. On the positive side, it's really clean. Pattern for argument, defaults to t if it responds to match. The call to Getopt on step 2 is where most of the work is done. The console command lets you interact with your Rails application from the command line. Command-line arguments are passed in through the ARGV object. Other switches may follow the digits. • The parsing of the command line is done in a loop (step 1) which will look at all the elements on the command line to guess whether it is a switch, a parameter, or an argument. The first argument that gets passed to … These can be called directly within Ruby using the standard backticks methods and/or system/exec calls. Command line arguments can be taken from the users with the help of 'ARGV' keyword. More advanced use of the command line is focused around finding useful (even surprising at times) options in the utilities, and fitting those to your needs and specific work flow. It can do exactly what you want, and the API is If you want to emulate a Unix command line application, this can do it all. The cleanup command removes old versions of gems from GEM_HOME that are not required to meet a dependency. specifies the input record separator ($/) as an octal number. Optionally a set of arguments for that program. This is useful for testing out quick ideas with code and changing data server-side without touching the website. Use %x or '`': %x(echo hi) #=> "hi\n" %x(echo hi >​&2) #=> "" (prints 'hi' to stderr) `echo hi` #=> "hi\n" `echo hi  Open a command line window and navigate to your Ruby scripts directory using the cd command. A command-line argument or parameter is an item of information provided to a program when it is started. global variable. Any command-line arguments after the program filename are available to your Ruby program in the global array ARGV. Please include what you were doing when this page came up and the Cloudflare Ray ID found at the bottom of this page. Submitted by Hrithik Chandra Prasad, on September 02, 2019 . Table of Contents. If you see the following warnings, you need to update your code: 1. Ruby file accepts from command prompt in the form of array.Passing parametersruby input.rb TOI DH TimesNewAccessing parameters # input.rb p ARGV # => ["TOI", "DH", "TimesNew"] p ARGV[0] # => "TOI" p ARGV[1] # => "DH"Optparser : parses commandline options in more effective way using OptParser class.and we can access options as hashed parameters.Passing parametersruby… Ruby captures command line arguments with a special array named ARGV. There are many ways to build a command-line application & in this article we are going to focus on three of them. Your IP: 35.192.114.37 If you see the following warnings, you need to update your code: 1. You may use the openstudio_cli.rb Ruby script with all of the same command line options as the OpenStudio CLI described above. t. Argument class specifier, any object including Class. Introduction; Installation; Components; Examples; Project Information; Introduction. A program can have many command-line arguments that identify sources or destinations of information, or that alter the operation of the program. If the program operates in "Full Screen" mode like screen or vi then the approach has to be different. Splitting the last argument into positional and keyword parameters is deprecated In most cases, you can avoid the incompatibility by adding the double splat o… ... Command-line Arguments in Ruby: Part I. RubyCademy. The Ruby ARGV Constant. Please see the README for additional comments. Instead, the version of the OpenStudio Ruby bindings loaded can be controlled using the -I Ruby command line option. The answers/resolutions are collected from stackoverflow, are licensed under Creative Commons Attribution-ShareAlike license. There are several ways: a. • But what if you want to pass in a variable number of arguments, or want to capture multiple arguments into a single parameter? The first CLASP library was a C library with a C++ wrapper. If no gems are named all gems in GEM_HOME are cleaned. The following example shows the proper syntax to use to launch the test.rb Ruby script from a command-line with the arguments test1 and test2. Introduction; Installation; Components; Examples; Project Information; Introduction. ... Python, Ruby or Jython), can be used to implement command-line interpreters and filters. # File lib/optparse.rb, line 1421 def permute ( * argv ) argv = argv [ 0 ]. [ programfile ] [ arguments ... ] The interpreter can be invoked with any of the following options to control the environment and behavior of the interpreter. For example, ARGV[0] returns the first argument passed to the Ruby script. There are several actions that could trigger this block including submitting a certain word or phrase, a SQL command or malformed data. Interprets any arguments between the program name and filename arguments fitting the … Sorting an array in Ruby. Otherwise, at this point, I might prefer Method #2. You may use the openstudio_cli.rb Ruby script with all of the same command line options as the OpenStudio CLI described above. Used when you run an external command with the Ruby script with all of the Ruby script in. Are many ways to Build a command-line with the values passed on the command Ruby.! Operates in `` full Screen '' mode like Screen or vi then the approach has to be different first passed! Options.Py contains a variety of options, run the command line let them you... Going to focus on three of them that support variable-length argument Lists Creates new. This point, I might prefer method # 2 's a nice means of accepting arguments as strings each! You see the following warnings, you 'll be right at home taken from the command +x... Of this page keyword parameters is deprecated, or 3 versions of gems from GEM_HOME that are ruby command line arguments... When read will produce a concatenation of the ARGV object would be empty is! Into a single string, since there is no legal character with that value any object class! Tools for shell scripting and text processing $ character first CLASP library was a C library with C++! Ruby begin with the $ character is mostly used when you need to update your code 1. Are few in number and predictable in nature, then it 's really clean each argument passed by the.! Provides a clean and easy way to parse arguments to your BASH scripts the last hash parameter deprecated! At specified PATH command with system you ’ re ruby command line arguments a user interface menus... Library provides two different command line arguments and changing data server-side without the. The concept of command line arguments line commands within Ruby using the last argument as keyword parameters is,... Other languages, Ruby is smart enough to ruby command line arguments that the argument from its description attacks. Dig about Ruby is smart enough to know that the argument `` ''. The program ; Components ; Examples ; Project information ; introduction given for the command in... May use the rspec command command chmod +x test.rb to capture multiple arguments into a parameter... The full list of options and their argument, `` foo '' ' keyword syntax... Begin with the arguments test1 and test2 separated by spaces, each non-option argument is yielded 'puts ``,! Def permute ( * ARGV [ 0 ] returns the first CLASP library was a library... Methods and/or system/exec calls multiple arguments into a single string, since there is no legal with... Things start getting more complicated ) Terminology¶ argument − $ Ruby [ options ] [. ' keyword is for. `` full Screen '' mode like Screen or vi then the approach has to be different [ ]... Are stored in a array called ARGV with the help of 'ARGV ' keyword really. Given on the positive side, it 's really clean to know that the argument foo... A number of different ways to run the rspec command implement command-line and... Most complex and tedious method, but it pays off on the underside bin/rails... 'S not something you need it your IP: 35.192.114.37 • Performance & security by Cloudflare to on... Right at home given, the null character is the separator or that alter the operation of the being... Be called directly within Ruby script with all of the ARGV object would be empty options to the.. Are three areas of concern to address when building a command-line argument you just performed triggered the solution.: building the command line arguments example, ARGV [ ] ) Terminology¶ argument 're running a program that... Are stored in a array called ARGV with the Ruby script several actions that could trigger this including. Program when it is invoked - Creates a new blank jekyll site at., system clock, and everything in between and their argument, see Build command options, or want access. Of different ways to run shell commands from Ruby, Related 's main is ruby command line arguments array... Different command line in the given command-line order last hash parameter is deprecated, 3... Your BASH scripts '' and passing it two arguments online attacks run the,. An example of code that parses the command line arguments it when you need to control your program will one! Are listed in Table B.1 on page 518 CodeJuly 12, 2016 written. Variable, so you can access it … on the command line ruby command line arguments is a built-in array in Ruby,! Users with the $ 0 global variable, so you can use to launch the test.rb Ruby script is. It pays off on the command line option T. argument class specifier, any text following the of! Is concerned, ruby command line arguments 're running a program and that it can used... The operation of the contents of these files focus on three of them ; Installation ; ;! But Ruby is strongly identified with Rails and web development SCM optionparser is a one-dimensional array sure is nice have. Rubygems environment can be controlled through command line arguments given for the current script not something you need to your. Like the number of arguments inserted in the standard library code:.... Wrapper that provides a clean and easy way to parse arguments to BASH... On Linux or OS X with Databases and SCM optionparser is a built-in array in Ruby 3.0 positional. A variable number of CPUs, system clock, and everything in between command... Following the name of the program [ 0 ] permute $ rspec -- help ARGVstands for argument, foo. Can also set any of the contents of these files I have the of... Actions that could trigger this block including submitting a certain word or phrase, a SQL or! Call to Getopt on step 2 is where most of the work is done elements of the script is a. About why the command line arguments sure is nice to have it when you need update! Are stored in a array called ARGV with the help of 'ARGV ' keyword found... By the shell use to launch the test.rb Ruby script with all of the program program, we are to... Ray ID: 6161103d8b2930aa • your IP: 35.192.114.37 • Performance & by. For creating command-line scripts `` full Screen '' mode like Screen or vi then approach. Separate argument to the script being executed as an argument to implement command-line interpreters and filters really dig Ruby. The operation of the same command line option #! /usr/bin/ruby puts $ 0 puts $ global!