Use #grep where it will suffice

Library/Homebrew/cmd/audit.rb

@@ -195,7 +195,7 @@ class FormulaAuditor
     urls = [(f.stable.url rescue nil), (f.devel.url rescue nil), (f.head.url rescue nil)].compact
 
     # Check GNU urls; doesn't apply to mirrors
-    urls.select { |u| u =~ %r[^(https?|ftp)://(?!alpha).+/gnu/] }.each do |u|
+    urls.grep(%r[^(https?|ftp)://(?!alpha).+/gnu/]).each do |u|
       problem "\"ftpmirror.gnu.org\" is preferred for GNU software (url is #{u})."
     end
 
@@ -230,12 +230,12 @@ class FormulaAuditor
     end
 
     # Check for git:// GitHub repo urls, https:// is preferred.
-    urls.select { |u| u =~ %r[^git://([^/])*github\.com/] }.each do |u|
+    urls.grep(%r[^git://([^/])*github\.com/]).each do |u|
       problem "Use https:// URLs for accessing GitHub repositories (url is #{u})."
     end
 
     # Check for http:// GitHub repo urls, https:// is preferred.
-    urls.select { |u| u =~ %r[^http://github\.com/.*\.git$] }.each do |u|
+    urls.grep(%r[^http://github\.com/.*\.git$]).each do |u|
       problem "Use https:// URLs for accessing GitHub repositories (url is #{u})."
     end 
 

Library/Homebrew/cmd/doctor.rb

@@ -1095,7 +1095,7 @@ module Homebrew extend self
     checks = Checks.new
 
     if ARGV.include? '--list-checks'
-      checks.methods.select { |m| m =~ /^check_/ }.sort.each { |m| puts m }
+      checks.methods.grep(/^check_/).sort.each { |m| puts m }
       exit
     end
 
@@ -1106,7 +1106,7 @@ module Homebrew extend self
       checks.methods.sort << "check_for_linked_keg_only_brews" << "check_for_outdated_homebrew"
     else
       ARGV.named
-    end.select{ |method| method =~ /^check_/ }.reverse.uniq.reverse
+    end.grep(/^check_/).reverse.uniq.reverse
 
     first_warning = true
     methods.each do |method|