Shell

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.

Installation

Add this line to your application's Gemfile:

gem'shell'

And then execute:

$ bundle

Or install it yourself as:

$ gem install shell

Usage

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 directorysh.mkdir"shell-test-1"unlesssh.exist?("shell-test-1")# make the 'shell-test-1' directory if it doesn't already existsh.cd("shell-test-1")# Change to the /tmp/shell-test-1 directoryfordirin["dir1","dir3","dir5"]if !sh.exist?(dir)sh.mkdirdir# make dir if it doesn't already existsh.cd(dir)do# change to the `dir` directoryf=sh.open("tmpFile","w")# open a new file in write modef.print"TEST\n"# write to the filef.close# close the file handlerendprintsh.pwd# output the process working directoryendend

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.transactdomkdir"shell-test-1"unlessexist?("shell-test-1")cd("shell-test-1")fordirin["dir1","dir3","dir5"]if !exist?(dir)mkdirdircd(dir)dof=open("tmpFile","w")f.print"TEST\n"f.closeendprintpwdendendend

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.newsh.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"

Development

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.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/ruby/shell.

License

The gem is available as open source under the terms of the 2-Clause BSD License.