Class: CouchShell::Shell

Inherits:
Object
  • Object
show all
Defined in:
lib/couch-shell/shell.rb

Overview

Starting a shell:

require "couch-shell/shell"

shell = CouchShell::Shell.new(STDIN, STDOUT, STDERR)
# returns at end of STDIN or on a quit command
shell.read_execute_loop

Defined Under Namespace

Classes: PluginLoadError

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(stdin, stdout, stderr) ⇒ Shell

Returns a new instance of Shell.



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# File 'lib/couch-shell/shell.rb', line 68

def initialize(stdin, stdout, stderr)
  @stdin = stdin
  @stdout = stdout
  @stderr = stderr
  @server_url = nil
  @pathstack = []
  @highline = HighLine.new(@stdin, @stdout)
  @responses = RingBuffer.new(10)
  @eval_context = EvalContext.new(self)
  @username = nil
  @password = nil
  @plugins = {}
  @commands = {}
  @variables = {}
  @variable_prefixes = []
  @stdout.puts "couch-shell #{VERSION}"
end

Instance Attribute Details

#password ⇒ Object

Returns the value of attribute password.



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# File 'lib/couch-shell/shell.rb', line 66

def password
  @password
end

#pathstack ⇒ Object (readonly)

Returns the value of attribute pathstack.



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# File 'lib/couch-shell/shell.rb', line 64

def pathstack
  @pathstack
end

#responses ⇒ Object (readonly)

A CouchShell::RingBuffer holding CouchShell::Response instances.



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# File 'lib/couch-shell/shell.rb', line 60

def responses
  @responses
end

#server_url ⇒ Object (readonly)

Returns the value of attribute server_url.



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# File 'lib/couch-shell/shell.rb', line 61

def server_url
  @server_url
end

#stdin ⇒ Object (readonly)

Returns the value of attribute stdin.



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# File 'lib/couch-shell/shell.rb', line 63

def stdin
  @stdin
end

#stdout ⇒ Object (readonly)

Returns the value of attribute stdout.



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# File 'lib/couch-shell/shell.rb', line 62

def stdout
  @stdout
end

#username ⇒ Object

Returns the value of attribute username.



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# File 'lib/couch-shell/shell.rb', line 65

def username
  @username
end

Instance Method Details

#cd(path, get = false) ⇒ Object 



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# File 'lib/couch-shell/shell.rb', line 168

def cd(path, get = false)
  old_pathstack = @pathstack.dup

  if path
    @pathstack = [] if path.start_with?("/")
    path.split('/').each { |elem|
      case elem
      when ""
        # do nothing
      when "."
        # do nothing
      when ".."
        if @pathstack.empty?
          @pathstack = old_pathstack
          raise ShellUserError, "Already at server root, can't go up"
        end
        @pathstack.pop
      else
        @pathstack << elem
      end
    }
  else
    @pathstack = []
  end

  old_dbname = old_pathstack[0]
  new_dbname = @pathstack[0]
  getdb = false
  if new_dbname && (new_dbname != old_dbname)
    getdb = get && @pathstack.size == 1
    res = request("GET", "/#{new_dbname}", nil, getdb)
    unless res.ok? && (json = res.json_value) &&
        json.object? && json["db_name"] &&
        json["db_name"].unwrapped! == new_dbname
      @pathstack = old_pathstack
      raise ShellUserError, "not a database: #{new_dbname}"
    end
  end
  if get && !getdb
    if request("GET", nil).code != "200"
      @pathstack = old_pathstack
    end
  end
end

#editor_bin! ⇒ Object 



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# File 'lib/couch-shell/shell.rb', line 517

def editor_bin!
  ENV["EDITOR"] or
    raise ShellUserError, "EDITOR environment variable not set"
end

#errmsg(str) ⇒ Object 



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# File 'lib/couch-shell/shell.rb', line 222

def errmsg(str)
  @stderr.puts @highline.color(str, :red)
end

#eval_expr(expr) ⇒ Object

Evaluate the given expression.



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# File 'lib/couch-shell/shell.rb', line 494

def eval_expr(expr)
  @eval_context.instance_eval(expr)
end

#execute(input) ⇒ Object

When the user enters something, it is passed to this method for execution. You may call it programmatically to simulate user input.

If input is nil, it is interpreted as “end of input”, raising a CouchShell::Shell::Quit exception. This exception is also raised by other commands (e.g. “exit” and “quit”). All other exceptions are caught and displayed on stderr.



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# File 'lib/couch-shell/shell.rb', line 384

def execute(input)
  begin
    execute!(input)
  rescue Quit => e
    raise e
  rescue Interrupt
    @stdout.puts
    errmsg "interrupted"
  rescue UndefinedVariable => e
    errmsg "Variable `" + e.varname + "' is not defined."
  rescue ShellUserError => e
    errmsg e.message
  rescue Errno::ETIMEDOUT => e
    errmsg "timeout: #{e.message}"
  rescue SocketError, Errno::ENOENT => e
    @stdout.puts
    errmsg "#{e.class}: #{e.message}"
  rescue Exception => e
    #p e.class.instance_methods - Object.instance_methods
    errmsg "#{e.class}: #{e.message}"
    errmsg e.backtrace[0..5].join("\n")
  end
end

#execute!(input) ⇒ Object

Basic execute without error handling. Raises various exceptions.



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# File 'lib/couch-shell/shell.rb', line 409

def execute!(input)
  case input
  when nil
    raise Quit
  when ""
    # do nothing
  else
    execute_command! *input.split(/\s+/, 2)
  end
end

#execute_command!(commandref, argstr = nil) ⇒ Object 



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# File 'lib/couch-shell/shell.rb', line 420

def execute_command!(commandref, argstr = nil)
  if commandref.start_with?("@")
    # qualified command
    if commandref =~ /\A@([^\.]+)\.([^\.]+)\z/
      plugin_name = $1
      command_name = $2
      plugin = @plugins[plugin_name]
      raise NoSuchPluginRegistered.new(plugin_name) unless plugin
      ci = plugin.plugin_info.commands[command_name]
      raise NoSuchCommandInPlugin.new(plugin_name, command_name) unless ci
      plugin.send ci.execute_message, argstr
    else
      raise ShellUserError, "invalid command syntax"
    end
  else
    # unqualified command
    ci = @commands[commandref]
    raise NoSuchCommand.new(commandref) unless ci
    @plugins[ci.plugin.plugin_name].send ci.execute_message, argstr
  end
end

#expand(url) ⇒ Object 



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# File 'lib/couch-shell/shell.rb', line 325

def expand(url)
  u = @server_url
  "#{u.scheme}://#{u.host}:#{u.port}#{full_path url}"
end

#full_path(path) ⇒ Object 



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# File 'lib/couch-shell/shell.rb', line 330

def full_path(path)
  stack = []
  if path !~ %r{\A/}
    stack = @pathstack.dup
  end
  if @server_url.path && !@server_url.path.empty?
    stack.unshift @server_url.path
  end
  if path && !path.empty? && path != "/"
    stack.push path
  end
  fpath = stack.join("/")
  if fpath !~ %r{\A/}
    "/" + fpath
  else
    fpath
  end
end

#http_client_request(method, absolute_url, body) ⇒ Object 



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# File 'lib/couch-shell/shell.rb', line 302

def http_client_request(method, absolute_url, body)
  file = nil
  headers = {}
  if body.kind_of?(FileToUpload)
    file_to_upload = body
    file = File.open(file_to_upload.filename, "rb")
    body = [{'Content-Type' => file_to_upload.content_type!,
             'Content-Transfer-Encoding' => 'binary',
             :content => file}]
    #body = {'upload' => file}
  elsif body && body =~ JSON_DOC_START_RX
    headers['Content-Type'] = "application/json"
  end
  hclient = HTTPClient.new
  if @username && @password
    hclient.set_auth lookup_var("server"), @username, @password
  end
  res = hclient.request(method, absolute_url, body, headers)
  Response.new(res)
ensure
  file.close if file
end

#interpolate(str) ⇒ Object 



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# File 'lib/couch-shell/shell.rb', line 452

def interpolate(str)
  return nil if str.nil?
  String.new.force_encoding(str.encoding).tap { |res|
    escape = false
    dollar = false
    expr = nil
    str.each_char { |c|
      if escape
        res << c
        escape = false
        next
      elsif c == '\\'
        escape = true
      elsif c == '$'
        dollar = true
        next
      elsif c == '('
        if dollar
          expr = ""
        else
          res << c
        end
      elsif c == ')'
        if expr
          res << eval_expr(expr).to_s
          expr = nil
        else
          res << c
        end
      elsif dollar
        res << "$"
      elsif expr
        expr << c
      else
        res << c
      end
      dollar = false
    }
  }
end

#lookup_var(var) ⇒ Object

Lookup unqualified variable name.



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# File 'lib/couch-shell/shell.rb', line 499

def lookup_var(var)
  vi = @variables[var]
  if vi
    plugin = @plugins[vi.plugin.plugin_name]
    plugin.send vi.lookup_message
  else
    vi = @variable_prefixes.find { |v|
      var.start_with?(v.prefix) && var.length > v.prefix.length
    }
    raise UndefinedVariable.new(var) unless vi
    plugin = @plugins[vi.plugin.plugin_name]
    plugin.send vi.lookup_message, var[vi.prefix.length]
  end
rescue Plugin::VarNotSet => e
  e.var = vi
  raise e
end

#msg(str, newline = true) ⇒ Object 



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# File 'lib/couch-shell/shell.rb', line 213

def msg(str, newline = true)
  @stdout.print @highline.color(str, :blue)
  if newline
    @stdout.puts
  else
    @stdout.flush
  end
end

#net_http_request(method, fpath, body) ⇒ Object 



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# File 'lib/couch-shell/shell.rb', line 273

def net_http_request(method, fpath, body)
  res = nil
  Net::HTTP.start(@server_url.host, @server_url.port) do |http|
    req = (case method
           when "GET"
             Net::HTTP::Get
           when "PUT"
             Net::HTTP::Put
           when "POST"
             Net::HTTP::Post
           when "DELETE"
             Net::HTTP::Delete
           else
             raise "unsupported http method: `#{method}'"
           end).new(fpath)
    if @username && @password
      req.basic_auth @username, @password
    end
    if body
      req.body = body
      if req.content_type.nil? && req.body =~ JSON_DOC_START_RX
        req.content_type = "application/json"
      end
    end
    res = Response.new(http.request(req))
  end
  res
end

#normalize_server_url(url) ⇒ Object 



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# File 'lib/couch-shell/shell.rb', line 145

def normalize_server_url(url)
  return nil if url.nil?
  # remove trailing slash
  url = url.sub(%r{/\z}, '')
  # prepend http:// if scheme is omitted
  if url =~ /\A\p{Alpha}(?:\p{Alpha}|\p{Digit}|\+|\-|\.)*:\/\//
    url
  else
    "http://#{url}"
  end
end

#plugin(plugin_name) ⇒ Object

Raises:



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# File 'lib/couch-shell/shell.rb', line 86

def plugin(plugin_name)
  # load and instantiate
  feature = "couch-shell-plugin/#{plugin_name}"
  begin
    require feature
  rescue LoadError
    raise PluginLoadError, "feature #{feature} not found"
  end
  pi = PluginInfo[plugin_name]
  raise PluginLoadError, "plugin class not found" unless pi
  plugin = pi.plugin_class.new(self)

  # integrate plugin variables
  ## enable qualified reference via @PLUGIN.VAR syntax
  @eval_context._instance_variable_set(
    :"@#{plugin_name}", plugin.variables_object)
  ## enable unqualified reference
  pi.variables.each { |vi|
    if vi.name
      existing = @variables[vi.name]
      if existing
        warn "When loading plugin #{plugin_name}: " +
          "Variable #{vi.name} already defined by plugin " +
          "#{existing.plugin.plugin_name}\n" +
          "You can access it explicitely via @#{plugin_name}.#{vi.name}"
      else
        @variables[vi.name] = vi
      end
    end
    if vi.prefix
      existing = @variable_prefixes.find { |e| e.prefix == vi.prefix }
      if existing
        warn "When loading plugin #{plugin_name}: " +
          "Variable prefix #{vi.prefix} already defined by plugin " +
          "#{existing.plugin.plugin_name}\n" +
          "You can access it explicitely via @#{plugin_name}.#{vi.prefix}*"
      else
        @variable_prefixes << vi
      end
    end
  }

  # integrate plugin commands
  pi.commands.each_value { |ci|
    existing = @commands[ci.name]
    if existing
      warn "When loading plugin #{plugin_name}: " +
        "Command #{ci.name} already defined by plugin " +
        "#{existing.plugin.plugin_name}\n" +
        "You can access it explicitely via @#{plugin_name}.#{ci.name}"
    else
      @commands[ci.name] = ci
    end
  }

  @plugins[plugin_name] = plugin
  plugin.plugin_initialization
end

#print_response(res, label = "", show_body = true) ⇒ Object 



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# File 'lib/couch-shell/shell.rb', line 231

def print_response(res, label = "", show_body = true)
  @stdout.print @highline.color("#{res.code} #{res.message}", :cyan)
  msg " #{label}"
  if show_body
    if res.json
      @stdout.puts res.json_value.to_s(true)
    elsif res.body
      @stdout.puts res.body
    end
  elsif res.body
    msg "body has #{res.body.bytesize} bytes"
  end
end

#prompt_msg(msg, newline = true) ⇒ Object 



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# File 'lib/couch-shell/shell.rb', line 349

def prompt_msg(msg, newline = true)
  @stdout.print @highline.color(msg, :yellow)
  if newline
    @stdout.puts
  else
    @stdout.flush
  end
end

#read ⇒ Object

Displays the standard couch-shell prompt and waits for the user to enter a command. Returns the user input as a string (which may be empty), or nil if the input stream is closed.



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# File 'lib/couch-shell/shell.rb', line 361

def read
  lead = @pathstack.empty? ? ">>" : @pathstack.join("/") + " >>"
  begin
    @highline.ask(@highline.color(lead, :yellow) + " ") { |q|
      q.readline = true
    }
  rescue Interrupt
    @stdout.puts
    errmsg "interrupted"
    return ""
  rescue NoMethodError
    # this is BAD, but highline 1.6.1 reacts to CTRL+D with a NoMethodError
    return nil
  end
end

#read_execute_loop ⇒ Object

Start regular shell operation, i.e. reading commands from stdin and executing them. Returns when the user issues a quit command.



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# File 'lib/couch-shell/shell.rb', line 444

def read_execute_loop
  loop {
    execute(read)
  }
rescue Quit
  msg "bye"
end

#read_secret ⇒ Object 



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# File 'lib/couch-shell/shell.rb', line 522

def read_secret
  @highline.ask(" ") { |q| q.echo = "*" }
end

#request(method, path, body = nil, show_body = true) ⇒ Object

Returns CouchShell::Response or raises an exception.



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# File 'lib/couch-shell/shell.rb', line 246

def request(method, path, body = nil, show_body = true)
  unless @server_url
    raise ShellUserError, "Server not set - can't perform request."
  end
  fpath = URI.encode(full_path(path))
  msg "#{method} #{fpath} ", false
  if @server_url.scheme != "http"
    raise ShellUserError,
      "Protocol #{@server_url.scheme} not supported, use http."
  end
  # HTTPClient and CouchDB don't work together with simple put/post
  # requests to due some Keep-alive mismatch.
  #
  # Net:HTTP doesn't support file upload streaming.
  if body.kind_of?(FileToUpload) || method == "GET"
    res = http_client_request(method, URI.encode(expand(path)), body)
  else
    res = net_http_request(method, fpath, body)
  end
  @responses << res
  rescode = res.code
  vars = ["r#{@responses.index}"]
  vars << ["j#{@responses.index}"] if res.json
  print_response res, "  vars: #{vars.join(', ')}", show_body
  res
end

#server=(url) ⇒ Object 



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# File 'lib/couch-shell/shell.rb', line 157

def server=(url)
  if url
    @server_url = URI.parse(normalize_server_url(url))
    msg "Set server to #{lookup_var 'server'}"
    request("GET", nil)
  else
    @server_url = nil
    msg "Set server to none."
  end
end

#warn(str) ⇒ Object 



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# File 'lib/couch-shell/shell.rb', line 226

def warn(str)
  @stderr.print @highline.color("warning: ", :red)
  @stderr.puts @highline.color(str, :blue)
end