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:
And then execute:
Or install it yourself as:
$ gem install shell
Temp file creation
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.exists?("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.exists?(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
Temp file creation with self
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 exists?("shell-test-1") cd("shell-test-1") for dir in ["dir1", "dir3", "dir5"] if !exists?(dir) mkdir dir cd(dir) do f = open("tmpFile", "w") f.print "TEST\n" f.close end print pwd end end end
Pipe /etc/printcap into a file
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.