IO::Tail for Ruby

Description

This is a small ruby library that allows it to “tail” various IOs in Ruby, including following a file, that still is growing like the unix command ‘tail -f’ can.

Download

The latest version of IO::Tail (io-tail) can be found at

github.com/octplane/ruby-io-tail

Online Documentation should be located at

rubydoc.info/github/octplane/ruby-io-tail/

Installation

To install io-tail via its gem type:

# gem install io-tail

To install from the source repository, just type into the command line as root:

# rake install

Usage

File::Tail is a module in the File class. A lightweight class interface for logfiles can be seen under File::Tail::Logfile.

Direct extension of File objects with File::Tail works like that:

File.open(filename) do |log|
  log.extend(File::Tail)
  log.interval = 10
  log.backward(10)
  log.tail { |line| puts line }
end

It’s also possible to mix File::Tail in your own File classes (see also File::Tail::Logfile):

class MyFile < File
  include File::Tail
end
log = MyFile.new("myfile")
log.interval = 10
log.backward(10)
log.tail { |line| print line }

The forward/backward method returns self, so it’s possible to chain methods together like that:

log.backward(10).tail { |line| puts line }

A command line utility named rtail, that uses File::Tail is provided as well.

Documentation

To create the documentation of this module, type

$ rake doc

and the API documentation is generated.

In the examples direcotry is a small example of tail and pager program that use this module. You also may want look at the end of file/tail.rb for a little example.

Author

Pierre Baillet pierre@baillet.name

Florian Frank flori@ping.de

License

This is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License Version 2 as published by the Free Software Foundation: www.gnu.org/copyleft/gpl.html