Promote erb to default gems

1 files changed, 176 insertions, 0 deletions

diff --git a/libexec/erb b/libexec/erb
new file mode 100755
index 0000000000..2435224fe1
--- /dev/null
+++ b/libexec/erb
@@ -0,0 +1,176 @@
+#!/usr/bin/env ruby
+# Tiny eRuby --- ERB2
+# Copyright (c) 1999-2000,2002 Masatoshi SEKI
+# You can redistribute it and/or modify it under the same terms as Ruby.
+
+require 'erb'
+
+class ERB
+  module Main
+    def ARGV.switch
+      return nil if self.empty?
+      arg = self.shift
+      return nil if arg == '--'
+      case arg
+      when /\A-(.)(.*)/
+        if $1 == '-'
+          arg, @maybe_arg = arg.split(/=/, 2)
+          return arg
+        end
+        raise 'unknown switch "-"' if $2[0] == ?- and $1 != 'T'
+        if $2.size > 0
+          self.unshift "-#{$2}"
+          @maybe_arg = $2
+        else
+          @maybe_arg = nil
+        end
+        "-#{$1}"
+      when /\A(\w+)=/
+        arg
+      else
+        self.unshift arg
+        nil
+      end
+    end
+
+    def ARGV.req_arg
+      (@maybe_arg || self.shift || raise('missing argument')).tap {
+        @maybe_arg = nil
+      }
+    end
+
+    def trim_mode_opt(trim_mode, disable_percent)
+      return trim_mode if disable_percent
+      case trim_mode
+      when 0
+        return '%'
+      when 1
+        return '%>'
+      when 2
+        return '%<>'
+      when '-'
+        return '%-'
+      end
+    end
+    module_function :trim_mode_opt
+
+    def run(factory=ERB)
+      trim_mode = 0
+      disable_percent = false
+      variables = {}
+      begin
+        while switch = ARGV.switch
+          case switch
+          when '-x'                        # ruby source
+            output = true
+          when '-n'                        # line number
+            number = true
+          when '-v'                        # verbose
+            $VERBOSE = true
+          when '--version'                 # version
+            STDERR.puts factory.version
+            exit
+          when '-d', '--debug'             # debug
+            $DEBUG = true
+          when '-r'                        # require
+            require ARGV.req_arg
+          when '-S'                        # security level
+            warn 'warning: -S option of erb command is deprecated. Please do not use this.'
+            arg = ARGV.req_arg
+            raise "invalid safe_level #{arg.dump}" unless arg =~ /\A[0-1]\z/
+            safe_level = arg.to_i
+          when '-T'                        # trim mode
+            arg = ARGV.req_arg
+            if arg == '-'
+              trim_mode = arg
+              next
+            end
+            raise "invalid trim mode #{arg.dump}" unless arg =~ /\A[0-2]\z/
+            trim_mode = arg.to_i
+          when '-E', '--encoding'
+            arg = ARGV.req_arg
+            set_encoding(*arg.split(/:/, 2))
+          when '-U'
+            set_encoding(Encoding::UTF_8, Encoding::UTF_8)
+          when '-P'
+            disable_percent = true
+          when '--help'
+            raise "print this help"
+          when /\A-/
+            raise "unknown switch #{switch.dump}"
+          else
+            var, val = *switch.split('=', 2)
+            (variables ||= {})[var] = val
+          end
+        end
+      rescue                               # usage
+        STDERR.puts $!.to_s
+        STDERR.puts File.basename($0) +
+          " [switches] [var=value...] [inputfile]"
+        STDERR.puts <<EOU
+  -x               print ruby script
+  -n               print ruby script with line number
+  -v               enable verbose mode
+  -d               set $DEBUG to true
+  -r library       load a library
+  -E ex[:in]       set default external/internal encodings
+  -U               set default encoding to UTF-8
+  -T trim_mode     specify trim_mode (0..2, -)
+  -P               disable ruby code evaluation for lines beginning with %
+  var=value        set variable
+EOU
+        exit 1
+      end
+
+      $<.set_encoding(Encoding::UTF_8, nil)
+      src = $<.read
+      filename = $FILENAME
+      exit 2 unless src
+      trim = trim_mode_opt(trim_mode, disable_percent)
+      if safe_level.nil?
+        erb = factory.new(src, trim_mode: trim)
+      else
+        # [deprecated] This will be removed at Ruby 2.7.
+        erb = factory.new(src, safe_level, trim_mode: trim)
+      end
+      erb.filename = filename
+      if output
+        if number
+          erb.src.each_line.with_index do |line, l|
+            puts "%3d %s"%[l+1, line]
+          end
+        else
+          puts erb.src
+        end
+      else
+        bind = TOPLEVEL_BINDING
+        if variables
+          enc = erb.encoding
+          for var, val in variables do
+            val = val.encode(enc) if val
+            bind.local_variable_set(var, val)
+          end
+        end
+        erb.run(bind)
+      end
+    end
+    module_function :run
+
+    def set_encoding(extern, intern = nil)
+      verbose, $VERBOSE = $VERBOSE, nil
+      Encoding.default_external = extern unless extern.nil? || extern == ""
+      Encoding.default_internal = intern unless intern.nil? || intern == ""
+      [$stdin, $stdout, $stderr].each do |io|
+        io.set_encoding(extern, intern)
+      end
+    ensure
+      $VERBOSE = verbose
+    end
+    module_function :set_encoding
+    class << self; private :set_encoding; end
+  end
+end
+
+if __FILE__ == $0
+  ERB::Main.run
+end