Class: Podgraph::Trestle

Inherits:
Object
  • Object
show all
Defined in:
lib/podgraph/trestle.rb

Constant Summary collapse

NNL_MARK =

#veputs uses this to decide to put a newline or not to put.

'__NNL__'

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(conf) ⇒ Trestle

conf

Typically must be a reference to some global variable.



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# File 'lib/podgraph/trestle.rb', line 63

def initialize(conf)
  @conf = conf
  @conf[:verbose] = 0
  @conf[:banner] = "Usage: #{File.basename($0)} [options]"
  @conf[:config] =  Meta::NAME + '.yaml'
  @conf[:config_dirs] =  [ENV['HOME']+'/.'+Meta::NAME,
                          File.absolute_path("#{File.dirname(File.expand_path($0))}/../etc"),
                          '/usr/etc', '/usr/local/etc', '/etc',
                          "#{Gem.dir}/gems/#{Meta::NAME}-#{Meta::VERSION}/etc"
                         ]
  @conf[:config_env] = [Meta::NAME.upcase + '_CONF']

  @cl_parsing_times = 0 # not used
  @cl_opt_protect = false
end

Instance Attribute Details

#cl_opt_protect ⇒ Object (readonly)

Use this in your CL options to check if modifying some variable is not an idempotent act.



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# File 'lib/podgraph/trestle.rb', line 60

def cl_opt_protect
  @cl_opt_protect
end

Class Method Details

.cmd_run(cmd) ⇒ Object

Execute cmd and return a list [exit_status, stderr, stdout]. Very handy.



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# File 'lib/podgraph/trestle.rb', line 17

def self.cmd_run(cmd)
  so = sr = ''
  status = Open4::popen4(cmd) { |pid, stdin, stdout, stderr|
    so = stdout.read
    sr = stderr.read
  }
  [status.exitstatus, sr, so]
end

.errx(ec, t) ⇒ Object

Print an error message t and exit if ec > 0.



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# File 'lib/podgraph/trestle.rb', line 45

def self.errx(ec, t)
  STDERR.puts File.basename($0) + ' error: ' + t.to_s
  exit ec if ec > 0
end

.gem_libdir ⇒ Object

Return a directory with program libraries.



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# File 'lib/podgraph/trestle.rb', line 27

def self.gem_libdir
  t = ["#{File.dirname(File.expand_path($0))}/../lib/#{Podgraph::Meta::NAME}",
       "#{Gem.dir}/gems/#{Podgraph::Meta::NAME}-#{Podgraph::Meta::VERSION}/lib/#{Podgraph::Meta::NAME}",
       "lib/#{Podgraph::Meta::NAME}"]
  t.each {|i| return i if File.readable?(i) }
  fail "all paths are invalid: #{t}"
end

.in_path?(file) ⇒ Boolean

Analogue to shell command which.

Returns:

  • (Boolean) 


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# File 'lib/podgraph/trestle.rb', line 36

def self.in_path?(file)
  return true if file =~ %r%\A/% and File.exist? file

  ENV['PATH'].split(File::PATH_SEPARATOR).any? do |path|
    File.exist? File.join(path, file)
  end
end

.warnx(t) ⇒ Object

Print a warning.



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# File 'lib/podgraph/trestle.rb', line 51

def self.warnx(t)
  STDERR.puts File.basename($0) + ' warning: ' + t.to_s
end

Instance Method Details

#cl_parse(src, o = nil, simple = false) ⇒ Object

Parses CL-like options.

src

An array of options (usually ARGV).

If o is non nil function parses src immediately, otherwise it only creates OptionParser object and return it (if simple is false).



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# File 'lib/podgraph/trestle.rb', line 178

def cl_parse(src, o = nil, simple = false)
  if ! o then
#        puts "NEW o (#{cl_opt_protect})" + src.to_s 
    o = OptionParser.new
    o.banner = @conf[:banner]
    o.on('-v', 'Be more verbose.') { |i|
#          puts "cl_parsing_times "+cl_parsing_times.to_s
      @conf[:verbose] += 1 unless cl_opt_protect
    }
    o.on('-V', 'Show version & exit.') { |i|
      puts Meta::VERSION
      exit 0
    }
    o.on('--config NAME', "Set a config name (default is #{@conf[:config]})") {|i|
      @conf[:config] = i
    }
    o.on('--config-dirs', 'Show possible config locations') {
      @conf[:config_dirs].each { |j|
        f = j + '/' + @conf[:config]
        puts (File.readable?(f) ? '* ' : '  ') +  f
      }
      exit 0
    }

    return o if ! simple
  end

  begin
    o.parse!(src)
    @cl_parsing_times += 1
  rescue
    Trestle.errx(1, $!.to_s)
  end
end

#config_flat_load(rvars) ⇒ Object

Load a config file immediately if it contains ‘/’ in its name, otherwise search through several dirs for it.

rvars

a list of requied variables in the config

Return a loaded filename or nil on error.



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# File 'lib/podgraph/trestle.rb', line 142

def config_flat_load(rvars)
  p = ->(f) {
    if File.readable?(f)
      begin
        myconf = YAML.load_file(f)
      rescue
        abort("cannot parse #{f}: #{$!}")
      end
      rvars.each { |i|
        fail "missing or nil '#{i}' in #{f}" if ! myconf.key?(i.to_sym) || ! myconf[i.to_sym]
      }
      @conf.merge!(myconf)
      return @conf[:config]
    end
    return nil
  }

  if @conf[:config].index('/')
    return p.call(@config[:config])
  else
    @conf[:config_dirs].each {|dir|
      return dir+'/'+@conf[:config] if p.call(dir + '/' + @conf[:config])
    }
  end

  return nil
end

#config_parse(rvars, &block) ⇒ Object

Run all configuration parsing in a batch.

rvars

A list of variable names which must be in the configuration file.

If no block is given, only standard CL options will be analysed.



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# File 'lib/podgraph/trestle.rb', line 103

def config_parse(rvars, &block)
  cb = ->(b, src) {
    if b
      block.call src
    else
      # very basic default options
      cl_parse(src, nil, true)
    end
  }
  
  # 1. parse env
  @conf[:config_env].each {|i|
#        puts '0 run:'
    cb.call(block_given?, ENV[i].shellsplit) if ENV.key?(i)
  }

  # 2. parse CL in case of '--config' option
#      puts "\n1 run"
  @cl_opt_protect = true
  cb.call(block_given?, ARGV.dup)
  @cl_opt_protect = false

  # 3. load the configuration file & do the final CL parsing
  begin
#        puts "\n2 run"
    r = config_flat_load(rvars)
  rescue
    Trestle.errx(1, "cannot load config: #{$!}")
  end
  veputs(1, "Loaded config: #{r}")
  cb.call(block_given?, ARGV)
end

#veputs(level, t) ⇒ Object

level

A verbose level.

t

A string to print.

Don’t print t with a newline if it contains NNL_MARK at the end.



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# File 'lib/podgraph/trestle.rb', line 83

def veputs(level, t)
  t = t.dup
  nnl = nil
  if t.match(/#{NNL_MARK}$/)
    t.sub!(/#{$&}/, '')
    nnl = 1
  end

  if @conf[:verbose] >= level
    nnl ? print(t) : puts(t)
    STDOUT.flush
  end
end