Shell implements an idiomatic Ruby interface for common UNIX shell commands.
It provides users the ability to execute commands with filters and pipes, like sh
/csh
by using native facilities of Ruby.
Add this line to your application's Gemfile:
gem 'shell'
And then execute:
$ bundle
Or install it yourself as:
$ gem install shell
In this example we will create three tmpFile
's in three different folders under the /tmp
directory.
sh = Shell.cd("/tmp") # Change to the /tmp directory sh.mkdir "shell-test-1" unless sh.exist?("shell-test-1") # make the 'shell-test-1' directory if it doesn't already exist sh.cd("shell-test-1") # Change to the /tmp/shell-test-1 directory for dir in ["dir1", "dir3", "dir5"] if !sh.exist?(dir) sh.mkdir dir # make dir if it doesn't already exist sh.cd(dir) do # change to the `dir` directory f = sh.open("tmpFile", "w") # open a new file in write mode f.print "TEST\n" # write to the file f.close # close the file handler end print sh.pwd # output the process working directory end end
This example is identical to the first, except we're using CommandProcessor#transact
.
CommandProcessor#transact
executes the given block against self, in this case sh
; our Shell object. Within the block we can substitute sh.cd
to cd
, because the scope within the block uses sh
already.
sh = Shell.cd("/tmp") sh.transact do mkdir "shell-test-1" unless exist?("shell-test-1") cd("shell-test-1") for dir in ["dir1", "dir3", "dir5"] if !exist?(dir) mkdir dir cd(dir) do f = open("tmpFile", "w") f.print "TEST\n" f.close end print pwd end end end
In this example we will read the operating system file /etc/printcap
, generated by cupsd
, and then output it to a new file relative to the pwd
of sh
.
sh = Shell.new sh.cat("/etc/printcap") | sh.tee("tee1") > "tee2" (sh.cat < "/etc/printcap") | sh.tee("tee11") > "tee12" sh.cat("/etc/printcap") | sh.tee("tee1") >> "tee2" (sh.cat < "/etc/printcap") | sh.tee("tee11") >> "tee12"
After checking out the repo, run bin/setup
to install dependencies. Then, run rake test
to run the tests. You can also run bin/console
for an interactive prompt that will allow you to experiment.
To install this gem onto your local machine, run bundle exec rake install
. To release a new version, update the version number in version.rb
, and then run bundle exec rake release
, which will create a git tag for the version, push git commits and tags, and push the .gem
file to rubygems.org.
Bug reports and pull requests are welcome on GitHub at https://github.com/ruby/shell.
The gem is available as open source under the terms of the 2-Clause BSD License.