Initial import

shard.yml

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+name: which-cr
+version: 0.1.0
+
+# authors:
+#   - name <email@example.com>
+
+# description: |
+#   Short description of which-cr
+
+# dependencies:
+#   pg:
+#     github: will/crystal-pg
+#     version: "~> 0.5"
+
+# development_dependencies:
+#   webmock:
+#     github: manastech/webmock.cr
+
+# license: MIT

src/which.cr

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+class Which
+  def initialize(@all_matches : Bool = false)
+  end
+
+  def find(programs : Array(String)) : Hash(String, Array(String))
+    results = Hash(String, Array(String)).new
+
+    programs.each do |program|
+      results[program] = find_program(program)
+    end
+
+    results
+  end
+
+  private def find_program(program : String) : Array(String)
+    matches = [] of String
+
+    if program.includes?("/")
+      matches << program if File.executable?(program)
+    else
+      ENV["PATH"].split(File::PATH_SEPARATOR).each do |path_element|
+        path = path_element.not_empty? ? path_element : "."
+        candidate = File.join(path, program)
+        if File.executable?(candidate)
+          matches << candidate
+          break unless @all_matches
+        end
+      end
+    end
+
+    matches
+  end
+end
+