Use class methods of File over Kernel#open and IO.read

enc/make_encmake.rb

@@ -134,7 +134,7 @@ def target_transcoders
 end
 mkin = File.read(File.join($srcdir, "Makefile.in"))
 mkin.gsub!(/@(#{CONFIG.keys.join('|')})@/) {CONFIG[$1]}
-open(ARGV[0], 'wb') {|f|
+File.open(ARGV[0], 'wb') {|f|
   f.puts mkin, dep
 }
 if MODULE_TYPE == :static

ext/extmk.rb

@@ -144,7 +144,7 @@ def extmake(target, basedir = 'ext', maybestatic = true)
     d = target
     until (d = File.dirname(d)) == '.'
       if File.exist?("#{$top_srcdir}/#{basedir}/#{d}/extconf.rb")
-        parent = (/^all:\s*install/ =~ IO.read("#{d}/Makefile") rescue false)
+        parent = (/^all:\s*install/ =~ File.read("#{d}/Makefile") rescue false)
         break
       end
     end
@@ -447,9 +447,8 @@ def $mflags.defined?(var)
 end
 for dir in ["ext", File::join($top_srcdir, "ext")]
   setup = File::join(dir, CONFIG['setup'])
-  if File.file? setup
-    f = open(setup)
-    while line = f.gets()
+  if (f = File.stat(setup) and f.file? rescue next)
+    File.foreach(setup) do |line|
       line.chomp!
       line.sub!(/#.*$/, '')
       next if /^\s*$/ =~ line
@@ -466,7 +465,6 @@ def $mflags.defined?(var)
     end
     MTIMES << f.mtime
     $setup = setup
-    f.close
     break
   end
 end unless $extstatic

ext/socket/extconf.rb

@@ -552,7 +552,7 @@ def %(s) s || self end
   end
 
   if !have_macro("IPPROTO_IPV6", headers) && have_const("IPPROTO_IPV6", headers)
-    IO.read(File.join(File.dirname(__FILE__), "mkconstants.rb")).sub(/\A.*^__END__$/m, '').split(/\r?\n/).grep(/\AIPPROTO_\w*/){$&}.each {|name|
+    File.read(File.join(File.dirname(__FILE__), "mkconstants.rb")).sub(/\A.*^__END__$/m, '').split(/\r?\n/).grep(/\AIPPROTO_\w*/){$&}.each {|name|
       have_const(name, headers) unless $defs.include?("-DHAVE_CONST_#{name.upcase}")
     }
   end
@@ -679,7 +679,7 @@ def %(s) s || self end
         end
       end
       FileUtils.mkdir_p(File.dirname(hdr))
-      open(hdr, "w") {|f| f.write(in6)}
+      File.write(hdr, in6)
       $distcleanfiles << hdr
       $distcleandirs << File.dirname(hdr)
       "done"

lib/mkmf.rb

@@ -1762,7 +1762,7 @@ def create_header(header = "extconf.h")
     hdr << "#endif\n"
     hdr = hdr.join("")
     log_src(hdr, "#{header} is")
-    unless (IO.read(header) == hdr rescue false)
+    unless (File.read(header) == hdr rescue false)
       File.open(header, "wb") do |hfile|
         hfile.write(hdr)
       end

tool/checksum.rb

@@ -36,9 +36,7 @@ def update?
   end
 
   def update!
-    open(@checksum, "wb") {|f|
-      f.puts("src=\"#{@source}\", len=#{@len}, checksum=#{@sum}")
-    }
+    File.binwrite(@checksum, "src=\"#{@source}\", len=#{@len}, checksum=#{@sum}")
   end
 
   def update

tool/enc-case-folding.rb

@@ -409,9 +409,7 @@ def debug!()  end
     s = f.string
   end
   if dest
-    open(dest, "wb") do |file|
-      file.print(s)
-    end
+    File.binwrite(dest, s)
   else
     STDOUT.print(s)
   end

tool/enc-emoji-citrus-gen.rb

@@ -71,7 +71,7 @@ def header(params)
 def generate_to_ucs(params, pairs)
   pairs.sort_by! {|u, c| c }
   name = "EMOJI_#{params[:name]}%UCS"
-  open("#{name}.src", "w") do |io|
+  File.open("#{name}.src", "w") do |io|
     io.print header(params.merge(name: name.tr('%', '/')))
     io.puts
     io.puts  "BEGIN_MAP"
@@ -83,7 +83,7 @@ def generate_to_ucs(params, pairs)
 def generate_from_ucs(params, pairs)
   pairs.sort_by! {|u, c| u }
   name = "UCS%EMOJI_#{params[:name]}"
-  open("#{name}.src", "w") do |io|
+  File.open("#{name}.src", "w") do |io|
     io.print header(params.merge(name: name.tr('%', '/')))
     io.puts
     io.puts  "BEGIN_MAP"

tool/expand-config.rb

@@ -16,7 +16,7 @@
 end
 
 if $output
-  output = open($output, "wb", $mode &&= $mode.oct)
+  output = File.open($output, "wb", $mode &&= $mode.oct)
   output.chmod($mode) if $mode
 else
   output = STDOUT

tool/gen-mailmap.rb

@@ -13,7 +13,7 @@
   email[name] |= mails
 end
 
-open(File.join(__dir__, "../.mailmap"), "w") do |f|
+File.open(File.join(__dir__, "../.mailmap"), "w") do |f|
   email.each do |name, mails|
     canonical = "#{ name }@ruby-lang.org"
     mails.delete(canonical)

tool/make_hgraph.rb

@@ -83,13 +83,12 @@ def self.module_refenreces_dot klass
 
   def self.module_refenreces_image klass, file
     dot = module_refenreces_dot(klass)
-    img = nil
-    IO.popen("dot -Tpng", 'r+'){|io|
+    img = IO.popen(%W"dot -Tpng", 'r+b') {|io|
       #
       io.puts dot
       io.close_write
-      img = io.read
+      io.read
     }
-    open(File.expand_path(file), 'w+'){|f| f.puts img}
+    File.binwrite(file, img)
   end
 end

tool/rbinstall.rb

@@ -143,7 +143,7 @@ def $mflags.defined?(var)
 
   if $installed_list ||= $mflags.defined?('INSTALLED_LIST')
     RbConfig.expand($installed_list, RbConfig::CONFIG)
-    $installed_list = open($installed_list, "ab")
+    $installed_list = File.open($installed_list, "ab")
     $installed_list.sync = true
   end
 
@@ -291,11 +291,11 @@ def install_recursive(srcdir, dest, options = {})
 end
 
 def open_for_install(path, mode)
-  data = open(realpath = with_destdir(path), "rb") {|f| f.read} rescue nil
+  data = File.binread(realpath = with_destdir(path)) rescue nil
   newdata = yield
   unless $dryrun
     unless newdata == data
-      open(realpath, "wb", mode) {|f| f.write newdata}
+      File.open(realpath, "wb", mode) {|f| f.write newdata}
     end
     File.chmod(mode, realpath)
   end
@@ -550,7 +550,7 @@ def prolog(shebang)
   def install(src, cmd)
     cmd = cmd.sub(/[^\/]*\z/m) {|n| transform(n)}
 
-    shebang, body = open(src, "rb") do |f|
+    shebang, body = File.open(src, "rb") do |f|
       next f.gets, f.read
     end
     shebang or raise "empty file - #{src}"
@@ -622,7 +622,7 @@ def stub
   has_goruby = File.exist?(goruby_install_name+exeext)
   require File.join(srcdir, "tool/mdoc2man.rb") if /\Adoc\b/ !~ $mantype
   mdocs.each do |mdoc|
-    next unless File.file?(mdoc) and open(mdoc){|fh| fh.read(1) == '.'}
+    next unless File.file?(mdoc) and File.read(mdoc, 1) == '.'
     base = File.basename(mdoc)
     if base == "goruby.1"
       next unless has_goruby
@@ -634,17 +634,14 @@ def stub
 
     if /\Adoc\b/ =~ $mantype
       if compress
-        w = open(mdoc) {|f|
-          stdin = STDIN.dup
-          STDIN.reopen(f)
-          begin
-            destfile << suffix
-            IO.popen(compress, &:read)
-          ensure
-            STDIN.reopen(stdin)
-            stdin.close
-          end
-        }
+        begin
+          w = IO.popen(compress, "rb", in: mdoc, &:read)
+        rescue
+        else
+          destfile << suffix
+        end
+      end
+      if w
         open_for_install(destfile, $data_mode) {w}
       else
         install mdoc, destfile, :mode => $data_mode
@@ -657,19 +654,19 @@ class << (w = [])
          File.basename(mdoc).start_with?('gemfile')
         w = File.read(mdoc)
       else
-        open(mdoc) {|r| Mdoc2Man.mdoc2man(r, w)}
+        File.open(mdoc) {|r| Mdoc2Man.mdoc2man(r, w)}
         w = w.join("")
       end
       if compress
-        require 'tmpdir'
-        Dir.mktmpdir("man") {|d|
-          dest = File.join(d, File.basename(destfile))
-          File.open(dest, "wb") {|f| f.write w}
-          if system(compress, dest)
-            w = File.open(dest+suffix, "rb") {|f| f.read}
-            destfile << suffix
+        begin
+          w = IO.popen(compress, "r+b") do |f|
+            Thread.start {f.write w; f.close_write}
+            f.read
           end
-        }
+        rescue
+        else
+          destfile << suffix
+        end
       end
       open_for_install(destfile, $data_mode) {w}
     end

win32/mkexports.rb

@@ -26,7 +26,7 @@ def self.extract(objs, *rest)
 
   def self.output(output = $output, &block)
     if output
-      open(output, 'wb', &block)
+      File.open(output, 'wb', &block)
     else
       yield STDOUT
     end