Getting a file location and name

ruby-talk
1

Hi,

Say I have /joe/configuration/config.rb:

···

==============================
puts "this configuration file is located in this directory: " +
File.dirname( ??? )
eval File.read(File.dirname( ??? ) + "/common.rb")
# other stuff

common.rb is located in /joe/configuration. It also contains some Ruby code.

The main program looks something like this:

config_file = ARGV.shift
eval File.read config_file

And I'd start the program via 'ruby main.rb /joe/configuration.rb'.

So, I have a main program that reads in a Ruby configuration file that
can also read other configuration files that are in a relative
directory. I'm having problems with the relative directory part. If
I hardcode the directory paths, everything's ok. But I don't want
/joe/configuration/config.rb to know that it's in /joe/configuration.
I just want that configuration file to be able to read
/joe/configuration/common.rb.

Sorry if this is confusing, let me know if I can clarify the question.

Joe

2

Don't worry Joe, this is a common problem, and fairly easily solved.
All you have to do is use Ruby's built-in library search path code,
with a special addition:

config.rb:

# Adds the directory containing this code to the search path
$:.unshift File.dirname(File.expand_path(__FILE__))
# Now require will work
require 'common'

Ryan

···

On 10/21/05, Joe Van Dyk <joevandyk@gmail.com> wrote:

So, I have a main program that reads in a Ruby configuration file that
can also read other configuration files that are in a relative
directory. I'm having problems with the relative directory part. If
I hardcode the directory paths, everything's ok. But I don't want
/joe/configuration/config.rb to know that it's in /joe/configuration.
I just want that configuration file to be able to read
/joe/configuration/common.rb.

Sorry if this is confusing, let me know if I can clarify the question.

3

Joe Van Dyk wrote:

Hi,

Say I have /joe/configuration/config.rb:

puts "this configuration file is located in this directory: " +
File.dirname( ??? )
eval File.read(File.dirname( ??? ) + "/common.rb")
# other stuff

common.rb is located in /joe/configuration. It also contains some Ruby code.

The main program looks something like this:

config_file = ARGV.shift
eval File.read config_file

And I'd start the program via 'ruby main.rb /joe/configuration.rb'.

So, I have a main program that reads in a Ruby configuration file that
can also read other configuration files that are in a relative
directory. I'm having problems with the relative directory part. If
I hardcode the directory paths, everything's ok. But I don't want
/joe/configuration/config.rb to know that it's in /joe/configuration.
I just want that configuration file to be able to read
/joe/configuration/common.rb.

Sorry if this is confusing, let me know if I can clarify the question.

Joe

What about something like

def with_load_path(path)
  $LOAD_PATH.unshift path
  yield
ensure
  $LOAD_PATH.shift
end

Then use that around your #eval call in the main program, with the
'/joe/configuration' as the argument. Then require should work relative
to the path you gave. (But note that $LOADED_FEATURES will prevent files
with the same name from being loaded again, even if in a different
config dir.)

Not thread safe, but oh well.

Another option: my "script" lib (see RAA). That makes sure that the
global $LOADED_FEATURES doesn't get affected.

···

--
      vjoel : Joel VanderWerf : path berkeley edu : 510 665 3407

4

Hi,

Say I have /joe/configuration/config.rb:

puts "this configuration file is located in this directory: " +
File.dirname( ??? )
eval File.read(File.dirname( ??? ) + "/common.rb")
# other stuff

common.rb is located in /joe/configuration. It also contains some
Ruby code.

The main program looks something like this:

config_file = ARGV.shift
eval File.read config_file

IMHO eval is completely superfluous here: just do

load config_file

==============================

And I'd start the program via 'ruby main.rb /joe/configuration.rb'.

So, I have a main program that reads in a Ruby configuration file that
can also read other configuration files that are in a relative
directory. I'm having problems with the relative directory part. If
I hardcode the directory paths, everything's ok. But I don't want
/joe/configuration/config.rb to know that it's in /joe/configuration.
I just want that configuration file to be able to read
/joe/configuration/common.rb.

If those other files do only belong to your config.rb (and are no files that you wish to require) then you can do this in config.rb

base = File.basename __FILE__

load File.join(base, "common.rb")

File.open(File.join(base, "common.rb") do |io|
....
end

File.open(File.join(base, "etc", "lib", "whatever.conf") do |io|
....
end

Kind regards

    robert

···

Joe Van Dyk <joevandyk@gmail.com> wrote:

5

From http://extensions.rubyforge.org/rdoc/classes/Kernel.html
# File lib/extensions/kernel.rb, line 38
    def require_relative(path)
      require File.join(File.dirname(caller[0]), path.to_str)
    end

Then simply:
    require_relative "common"
or
    require_relative "../../foo/bar/common"

"Joe Van Dyk" <joevandyk@gmail.com> wrote in message
I'm having problems with the relative directory part.