Module: Which

Defined in:
lib/which.rb

Overview

Skeleton module for the ‘which’ routine.

Ideally, one would do this in their code to import the “which” call directly into their current namespace:

require 'which'
include Which
# do something with which()

It is recommended that you look at the documentation for the which() call directly for specific usage.

The compilation of software known as which.rb is distributed under the following terms: Copyright © 2005-2006 Erik Hollensbe. All rights reserved.

Redistribution and use in source form, with or without modification, are permitted provided that the following conditions are met:

  1. Redistributions of source code must retain the above copyright

notice, this list of conditions and the following disclaimer.

THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS “AS IS” AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

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Class Method Summary collapse

Class Method Details

.which(filename, path = ENV["PATH"], path_sep = File::PATH_SEPARATOR, dir_sep = File::SEPARATOR) ⇒ Object

Searches the path, or a provided path with given separators (path_sep, commonly “:”) and a separator for directories (dir_sep, commonly “/” or “\” on windows), will return all of the places that filename occurs. ‘filename’ is included as a part of the output.

Note that the filename must both exist in the path and be executable for it to appear in the return value.

Those familiar with the which(1) utility from UNIX will notice the similarities.



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# File 'lib/which.rb', line 64

def which(filename, path=ENV["PATH"], path_sep=File::PATH_SEPARATOR, dir_sep=File::SEPARATOR)
  dirs = path.split(/#{path_sep}/)
  
  locations = []

  dirs.each do |dir|
    newfile = "#{dir}#{dir_sep}#{filename}"
    # strip any extra dir separators
    newfile.gsub!(/#{dir_sep}{2,}/, "#{dir_sep}")
    p = Pathname.new(newfile)
    if p.exist? and p.executable?
      locations.push(newfile)
    end
  end

  return locations
end