[Executable] Dont use a subprocess for which

lib/cocoapods/executable.rb

@@ -48,8 +48,8 @@ module Pod
     # @todo   Find a way to display the live output of the commands.
     #
     def self.execute_command(executable, command, raise_on_failure)
-      bin = `which #{executable}`.strip
-      raise Informative, "Unable to locate the executable `#{executable}`" if bin.empty?
+      bin = which(executable)
+      raise Informative, "Unable to locate the executable `#{executable}`" unless bin
 
       require 'shellwords'
 
@@ -75,6 +75,20 @@ module Pod
       output
     end
 
+    # Returns the absolute path to the binary with the given name on the current
+    # `PATH`, or `nil` if none is found.
+    #
+    def self.which(program)
+      program = program.to_s
+      ENV["PATH"].split(File::PATH_SEPARATOR).each do |path|
+        bin = File.expand_path(program, path)
+        if File.file?(bin) && File.executable?(bin)
+          return bin
+        end
+      end
+      nil
+    end
+
     private
 
     def self.popen3(bin, command, stdout, stderr)

lib/cocoapods/validator.rb

@@ -381,7 +381,7 @@ module Pod
     # @return [void]
     #
     def build_pod
-      if `which xcodebuild`.strip.empty?
+      if Executable.which('xcodebuild').nil?
         UI.warn "Skipping compilation with `xcodebuild' because it can't be found.\n".yellow
       else
         UI.message "\nBuilding with xcodebuild.\n".yellow do

spec/spec_helper.rb

@@ -70,7 +70,7 @@ end
 #-----------------------------------------------------------------------------#
 
 ENV['SKIP_SETUP'] = 'true'
-if ENV['SKIP_XCODEBUILD'].nil? && `which xcodebuild`.strip.empty?
+if ENV['SKIP_XCODEBUILD'].nil? && Pod::Executable.which('xcodebuild').nil?
   ENV['SKIP_XCODEBUILD'] = 'true'
 end
 

spec/unit/executable_spec.rb

@@ -12,7 +12,8 @@ module Pod
 
     it 'should support spaces in the full path of the command' do
       cmd = '/Spa ces/are"/fun/false'
-      Executable.stubs(:`).returns(cmd)
+      File.expects(:file?).with(cmd).returns(true)
+      File.expects(:executable?).with(cmd).returns(true)
       result = mock
       result.stubs(:success?).returns(true)
 

spec/unit/generator/bridge_support_spec.rb

 require File.expand_path('../../../spec_helper', __FILE__)
 
 describe 'Pod::Generator::BridgeSupport' do
-  if `which gen_bridge_metadata`.strip.empty?
+  if Executable.which('gen_bridge_metadata').nil?
     puts '  ! '.red << "Skipping because the `gen_bridge_metadata` executable can't be found."
   else
     it 'generates a metadata file with the appropriate search paths' do