# Rs 0.1.2 **URL:** \ **Category:** Ruby\ **Created:** [October 19, 2006, 8:48am UTC](https://www.ruby-forum.com/t/rs-0-1-2/72835 "2006-10-19T08:48:07Z")\ **Posts on this page:** 1\ **Page:** 1
**Author:** ![rue](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/b77776/32.png) [@rue](https://www.ruby-forum.com/u/rue)\ **Post date:** [October 19, 2006, 8:48am UTC](https://www.ruby-forum.com/t/rs-0-1-2/72835/1 "2006-10-19T08:48:07Z")
= rs === Synopsis rs is a project to implement a non-traditional object-oriented shell in Ruby. The three main features will be the simple power of Ruby as the shell scripting language, an objectlike interface to files and object piping. === Notes Version 0.1.2. This version has a rather more robust parser so entering Ruby code on the command-line is more natural. Some changes were also made to prompt handling. For all changes, see doc/CHANGES. Anyone who reads this entire post may award themselves one (1) pat on the back. Sorry about the length. === Authors See doc/AUTHORS. === Licence See doc/LICENCE. === Communication - IRC: ##rs on [irc.freenode.net](http://irc.freenode.net) (That is hash-hash-r-s) - Mailing list: [http://projects.kittensoft.org/mailman/listinfo/rs-dev\_projects.kittensoft.org](http://projects.kittensoft.org/mailman/listinfo/rs-dev_projects.kittensoft.org) - Bug tracker: [http://rubyforge.org/tracker/?group\_id=2377](http://rubyforge.org/tracker/?group_id=2377) === Documentation [http://projects.kittensoft.org/rs/rdoc/index.html](http://projects.kittensoft.org/rs/rdoc/index.html) === Features - Execution of arbitrary Ruby - Pipes, input redirection - FileSystemObjects which encapsulate paths and files A development roadmap is in doc/TODO.roadmap === Download ==== Developers Anyone interested in developing rs should read the doc/HOWTO.development document, available on the web (see Documentation) or in the distribution. - darcs get [http://repos.kittensoft.org/rs](http://repos.kittensoft.org/rs) - [http://files.kittensoft.org/rs/rs-dev-latest.tar.gz](http://files.kittensoft.org/rs/rs-dev-latest.tar.gz) ==== Users - [http://files.kittensoft.org/rs/rs-latest.tar.gz](http://files.kittensoft.org/rs/rs-latest.tar.gz) === Installation It is advised that developers do not install the program locally at this point but rather use bin/rs directly. Users may use the provided setup.rb script: sudo ruby setup.rb all === Using rs ==== General notes rs uses Readline which means that you can use the arrow keys to go up and down in history and back and forth in the current line. ==== Customising rs will load ~/.rs/rc file as Ruby code if it exists. You can use this file to execute any code you like each time rs starts up. ==== Executing Ruby code You should be able to execute any Ruby code on the line. The parser is reasonably robust but not nearly perfect. An expression continuing on another line can be indicated with \ at the end of a line. rs\> 5 + 6 =\> 11 rs\> rs\> class Foo …\> def bar …\> puts ‘Baz’ …\> end …\> end =\> nil rs\> Foo.new.bar Baz =\> nil rs\> a = [1, …\> 2] =\> [1,2] rs\> ==== Output and environment control You can affect the output using $config values of ruby\_return, prompt and continuation\_prompt. $config (and $env) behave like OpenStructs with the distinction that a method ending with ? returns a boolean and one ending with ! will set the attribute to true. Prompts may be set as static Strings or anything that responds to #call. rs\> 1 + 1 =\> 2 rs\> $config.ruby\_return = false rs\> 1 + 1 rs\> $config.ruby\_return! =\> true rs\> rs\> $config.prompt =\> "rs\> " rs\> $config.prompt = lambda {Dir.pwd + '\> '} =\> \<#Proc…\> /tmp\> class Foo …\> end /tmp\> $config.continuation\_prompt = $config.prompt =\> \<#Proc…\> /tmp\> ‘/home’.to\_fso.cd /home\> ‘/tmp’.to\_fso.cd /tmp\> class Foo /tmp\> end /tmp\> $config.prompt = "rs\> "; $config.continuation\_prompt = "…\> " =\> "rs\> " rs\> rs accesses the system and internal envs through $env. Any uppercase method name, such as $env.PATH, works on system envs. In contrast, any lowercase such as $env.path will not access or be propagated to the outside environment. ==== FileSystemObjects FSOs give a relatively object-like interface to files and paths and incorporate several File, FileUtils, Dir etc. methods. rs\> ‘/tmp’.to\_fso.methods.sort =\> [“/”, “\<”, “\<\<”, “====”, “=====”, “=~”, “\>”, “\>\>”, “ **id** ”, “ **send** ”, “append\_to”, “args”, “basename”, “blockdev?”, “cat”, “cd”, “chardev?”, “chmod”, “chmod\_R”, “chown”, “chown\_R”, “class”, “clone”, “compare”, “cp”, “cp\_r”, “directory?”, “dirname”, “display”, “dup”, “eql?”, “equal?”, “exec”, “executable?”, “executable\_real?”, “exist?”, “exists?”, “extend”, “extname”, “file?”, “find”, “freeze”, “frozen?”, “ftype”, “glob”, “grpowned?”, “hash”, “id”, “inspect”, “install”, “instance\_eval”, “instance\_of?”, “instance\_variable\_get”, “instance\_variable\_set”, “instance\_variables”, “is\_a?”, “kind\_of?”, “ln”, “ln\_s”, “ln\_sf”, “lstat”, “method”, “methods”, “mkdir”, “mkdir\_p”, “mv”, “nil?”, “object\_id”, “owned?”, “path”, “pipe”, “pipe?”, “private\_methods”, “protected\_methods”, “public\_methods”, “readable?”, “readable\_real?”, “readlink”, “relative\_path”, “respond\_to?”, “rm”, “rm\_r”, “rm\_rf”, “rmdir”, “run”, “send”, “setgid?”, “setuid?”, “singleton\_methods”, “size”, “size?”, “socket?”, “split”, “stat”, “sticky?”, “symlink”, “symlink?”, “taint”, “tainted?”, “to\_a”, “to\_os”, “to\_s”, “touch”, “truncate”, “type”, “umask”, “unlink”, “untaint”, “writable?”, “writable\_real?”, “write\_to”, “zero?”, “|”] rs\> Generally, these methods behave exactly as their Ruby counterparts with the path of the FSO given as the file to operate on. For example: rs\> ‘/tmp’.to\_fso.directory? =\> true rs\> ‘/tmp/quux’.to\_fso.exist? =\> false rs\> ‘/tmp’.to\_fso.cd {‘./quux’.to\_fso.touch} =\> nil rs\> ‘/tmp/quux’.to\_fso.exist? =\> true rs\> ‘/tmp/quux’.to\_fso.rm =\> [‘/tmp/quux’] rs\> ‘/tmp/quux’.to\_fso.exist? =\> false You could of course put the FSO in a variable to avoid the repetition–also, if you feel like metaprogramming a bit, you could put a String#method\_missing in your ~/.rs/rc so that you can skip the #to\_fso (which will eventually go away, of course). ==== Executing programs FSOs containing executable files may (unsurprisingly) be executed. One thing to know about the processing of FSOs is that currently any filename that does not start with ./, …/, / or ~/ is considered to be ‘unqualified’ and must exist in $PATH. In addition to this, unknown methods at the top-level are first treated as unqualified files (falling back on normal if not found). The UI provides special handling and will automatically run executables. Arguments may also be given. rs\> ‘ls’.to\_fso.run … =\> nil rs\> ls … =\> nil rs\> ls ‘-la’ … =\> nil rs\> ‘ls’.to\_fso.args(‘-l’) … =\> nil rs\> ==== Input redirection More or less arbitrary objects can be ‘redirected’, \> indicating overwriting and \>\> appending. In both cases, the file will be created if it does not exist. rs\> ‘/tmp/foo’.to\_fso.touch =\> [“/tmp/foo”] rs\> ‘/tmp/foo’.to\_fso.cat =\> nil rs\> ‘/tmp/foo’.to\_fso \< “Foo” =\> 3 rs\> ‘/tmp/foo’.to\_fso.cat Foo =\> nil rs\> ‘/tmp/foo’.to\_fso \<\< 45 =\> 2 rs\> ‘/tmp/foo’.to\_fso.cat Foo45 =\> nil rs\> ‘/tmp/nonexist’.to\_fso \< ‘/tmp/foo’.to\_fso.read =\> 5 rs\> ‘/tmp/nonexist’.to\_fso.cat Foo45 =\> nil rs\> The opposite should also work: rs\> ‘/tmp/nonexist’.to\_fso.cat Foo45 =\> nil rs\> 78 \>\> ‘/tmp/nonexist’.to\_fso =\> 2 rs\> ‘/tmp/nonexist’.to\_fso.cat Foo4578 =\> nil rs\> There are a few exceptions. If the ‘input’ is an Array, it is recursively joined with newlines. If the input is an executable FSO, it will be run and the result written as a String. Thirdly, if the file TO which the input is going is executable, it is converted to an ObjectStream instead. This brings us to our next topic. ==== Pipes Executable programs (and/or static input) can be chained together to an arbitrary degree using ObjectStreams, also known as pipes. The result of a piping operation can be queried with #result (this is done automatically by the UI if the value of the expression is an OS). Alternatively, an iterator interface is exposed with #each (an other Enumerable methods). A few modifications take place on a Ruby object being piped: Arrays are newline-joined, #to\_proc objects are #called and everything else is set to its #to\_s representation. rs\> ls | wc 8 8 46 =\> nil rs\> (ls | wc).result =\> [" 8 8 46"] rs\> “foo\nbar” | wc(‘-l’) 2 =\> nil rs\> “foo\nbar” | wc(‘-l’) 2 =\> nil rs\> (ls | tr(‘a-z A-Z’)).each {|f| p f.reverse} “ELIFEKAR” “SCRAD\_” “NIB” “OOB” “COD” “BIL” “BR.PUTES” “TSET” =\> #IO:0x65be40 rs\> lambda {“foo\nbar”} | wc 2 2 8 =\> nil rs\> === Current issues and bugs The entire project is in flux. Think of it as an exploratory programming experiment that will stretch all the way until 0.9 at which point the real program will be extracted from the codebase at the time. - Generally not production-ready. - Cannot be used as a login shell. - Inconsistent and incomplete internal model. - The ‘lexer’ for determining completeness of Ruby statements has been improved but is still somewhat weak. - Tests, though relatively extensive, mainly ensure that the correct operation is present. Work is needed in testing for failure. === Dependencies ==== Bundled - Test::Spec by Christian N., [http://chneukirchen.org](http://chneukirchen.org). Developers only. - FlexMock by Jim W., [http://onestepback.org/software/flexmock](http://onestepback.org/software/flexmock). Developers only. ==== Unbundled - None === Special thanks - Everyone who contributed to the original ruSH code. - The Ruby hackers. I never appreciated the UNIXness of Ruby enough. === Copyright Copyright (c) 2005-2006 by the Authors. All rights reserved.