Can I install a man page using gem spec?

Question

Is there any way to install man pages using gem specification?

For example, gem install XXX-1.0.0.gem should install the man page to the system.

Answer 1

Rubygems currently doesn't support installing manpages for gems.

A patch was submitted to Rubygems a while ago to add support for manpages, but it was rejected.

Answer 2

You can use the gem-man gem to install manpages for gems.

They also offer a "cheating switch" to use the global man: alias man="gem man -s"

Answer 3

I think i have found a solution:

At first, you have to add a native extension to the gem:

my_gem.gemspec:

s.extensions << 'manpage/extconf.rb'
s.files << 'manpage/my_gem.1'

Then gem install will execute the extconf.rb and wants to call a Makefile.

make clean
make 
make install

So the extconf.rb can be used to create the Makefile. You also have to make sure, that there must be at least a dummy Makefile or else the installation will fail.

makefile = "make:\n" \
           "\t%s\n" \
           "install:\n" \
           "\t%s\n" \
           "clean:\n" \
           "\t%s\n"

if RUBY_PLATFORM =~ /linux/

  clean = 'sudo rm -f /usr/local/share/man/man1/my_gem.1.gz'
  make = 'gzip my_gem.1'
  install = 'sudo cp -r my_gem.1.gz /usr/local/share/man/man1/'

  puts
  puts 'You need super user privileges to install the manpage for my_gem.'
  puts 'Do you want to proceed? (y/n)'
  puts 'The gem will be installed anyways.'
  input = STDIN.gets.chomp.strip.downcase

  if input == 'y' or input == 'yes'
    File.write('Makefile', makefile % [make, install, clean])
  else
    File.write('Makefile', makefile % [':', ':', ':']) # dummy makefile
  end

else
  File.write('Makefile', makefile % [':', ':', ':']) # dummy makefile
end