brew/Library/Homebrew/install.rb

#!/usr/bin/ruby
require 'global'
require 'formula'
require 'keg'
require 'brew.h'

show_summary_heading = false

def text_for_keg_only_formula f
  <<-EOS
#{f.name} is keg-only. This means it is not symlinked into Homebrew's
prefix. The formula provides the following rationale:

#{f.keg_only?}

Generally there are no consequences of this for you, however if you build your
own software and it requires this formula, you may want to run this command to
link it into the Homebrew prefix:

     brew link #{f.name}
  EOS
end

def install f  
  build_time = nil

  begin
    f.brew do
      if ARGV.flag? '--interactive'
        ohai "Entering interactive mode"
        puts "Type `exit' to return and finalize the installation"
        puts "Install to this prefix: #{f.prefix}"
        interactive_shell
        nil
      elsif ARGV.include? '--help'
        system './configure --help'
        exit $?
      else
        f.prefix.mkpath
        beginning=Time.now
        f.install
        %w[README ChangeLog COPYING LICENSE COPYRIGHT AUTHORS].each do |file|
          FileUtils.mv "#{file}.txt", file rescue nil
          f.prefix.install file rescue nil
        end
        build_time = Time.now-beginning
      end
    end
  rescue Exception
    if f.prefix.directory?
      f.prefix.rmtree
      f.prefix.parent.rmdir_if_possible
    end
    raise
  end

  if f.caveats
    ohai "Caveats", f.caveats
    show_summary_heading = true
  end

  ohai 'Finishing up' if ARGV.verbose?
  
  begin
    clean f
  rescue Exception => e
    opoo "The cleaning step did not complete successfully"
    puts "Still, the installation was successful, so we will link it into your prefix"
    ohai e, e.inspect if ARGV.debug?
    show_summary_heading = true
  end

  raise "Nothing was installed to #{f.prefix}" unless f.installed?

  # warn the user if stuff was installed outside of their PATH
  paths = ENV['PATH'].split(':').collect{|p| File.expand_path p}
  [f.bin, f.sbin].each do |bin|
    if bin.directory?
      rootbin = (HOMEBREW_PREFIX+bin.basename).to_s
      bin = File.expand_path bin
      unless paths.include? rootbin
        opoo "#{rootbin} is not in your PATH"
        puts "You can amend this by altering your ~/.bashrc file"
        show_summary_heading = true
      end
    end
  end

  if f.keg_only?
    ohai 'Caveats', text_for_keg_only_formula(f)
    show_summary_heading = true
  else
    begin
      Keg.new(f.prefix).link
    rescue Exception
      onoe "The linking step did not complete successfully"
      puts "The package built, but is not symlinked into #{HOMEBREW_PREFIX}"
      puts "You can try again using `brew link #{f.name}'"
      ohai e, e.inspect if ARGV.debug?
      show_summary_heading = true
    end
  end

  ohai "Summary" if ARGV.verbose? or show_summary_heading
  print "#{f.prefix}: #{f.prefix.abv}"
  print ", built in #{pretty_duration build_time}" if build_time
  puts

rescue Exception => e
  #TODO propogate exception back to brew script
  onoe e
  puts e.backtrace
end


# I like this little at all, but see no alternative seeing as the formula
# rb file has to be the running script to allow it to use __END__ and DATA
at_exit { install(Formula.factory($0)) }