ExecutablePathname

The executable_pathname gem provides additional methods for inspecting executable pathnames, within a subclass of the Pathname class.

Installation

Add this line to your application's Gemfile:

gem 'executable_pathname'

And then execute:

$ bundle

Or install it yourself as:

$ gem install executable_pathname

Usage

require 'executable_pathname'

Class Methods

.valid_executable?(path)

Returns true if path is a valid executable file, where validity is determined by examining the file, and ensuring that if it is a "hash-bang" script, that the hash-bang path exists, or is likely to exist.

.path_list

Returns the current environment variable PATH split into an array.

.remote_path_list

Returns the remote path list, as an array, which is obtained from the envar REMOTE_PATH, if defined, or defaults to '/bin:/usr/bin:/usr/local/bin' (split into an array).

.new(path)

Creates a new instance of an ExecutablePathname, with the below instance methods.

Instance Methods

#first_line

Returns the first line of the file at path, if text.

#shbang?

Returns true if the first line of the file at path starts with #!. "shbang" is a contraction of "hash bang".

#shbang_paths

Returns the paths from the hash-bang line. If the hash-bang line looks like this:

#!/path/to/some/file arg1 arg2

then the resulting array from shbang_paths is ['/path/to/some/file', 'arg1', 'arg2'].

#env_shbang?

Returns true if the first_line value contains at least two paths, the first of which ends with /env

#valid_shbang?

Returns true if the first_line is a valid hash-bang, where validity is determined by the actual existence of the first path, or the probable existence of the path, based on it being one of the well-known paths from REMOTE_PATH.

#invalid_shbang?

Returns false if the first_line value is not a valid hash-bang.

#valid_env_shbang?

Returns false if the first_line value is not a valid env hash-bang path.

#executable_file?

Returns true if the instance is an executable file.

#valid_executable?

Returns true if the instance is a valid executable file; that is, if the hash-bang path exists, or is in a well-known path.

#well_known_path?

Returns true if the instance path is in one of the REMOTE_PATH directories.

#remove_execute_permissions

Removes the execute permissions on the instance. An error is raised if the instance path does not exist.

Development

After checking out the repo, run bin/setup to install dependencies. 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/aks/executable_pathname. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.

License

The gem is available as open source under the terms of the MIT License.