How to ping for reachability of remote host in Ruby

If you're on a *nix machine (OSX/Linux/BSD...), you can always tell Ruby (by using back ticks) to use the command line and save the results.

x = `ping -c 1 10.102.52.42`
# do whatever with X

The -c 1 parameter tells it to run once. You can set this to any number you find fit. If you don't set -c, it'll run until it's interrupted which will cause your program to stall.

Ping with External, UDP, HTTP, etc. Modify as you see fit. You can read more at ping-net git-repo.

1.

########################################################################
# example_pingexternal.rb
#
# A short sample program demonstrating an external ping. You can run
# this program via the example:external task. Modify as you see fit.
########################################################################
require 'net/ping'

good = 'www.rubyforge.org'
bad  = 'foo.bar.baz'

p1 = Net::Ping::External.new(good)
p p1.ping?

p2 = Net::Ping::External.new(bad)
p p2.ping?

2.

########################################################################
# example_pinghttp.rb
#
# A short sample program demonstrating an http ping. You can run
# this program via the example:http task. Modify as you see fit.
########################################################################
require 'net/ping'

good = 'http://www.google.com/index.html'
bad  = 'http://www.ruby-lang.org/index.html'

puts "== Good ping, no redirect"

p1 = Net::Ping::HTTP.new(good)
p p1.ping?

puts "== Bad ping"

p2 = Net::Ping::HTTP.new(bad)
p p2.ping?
p p2.warning
p p2.exception

3.

########################################################################
# example_pingtcp.rb
#
# A short sample program demonstrating a tcp ping. You can run
# this program via the example:tcp task. Modify as you see fit.
########################################################################
require 'net/ping'

good = 'www.google.com'
bad  = 'foo.bar.baz'

p1 = Net::Ping::TCP.new(good, 'http')
p p1.ping?

p2 = Net::Ping::TCP.new(bad)
p p2.ping?

4.

ping-1.7.8/examples/example_pingudp.rb
########################################################################
# example_pingudp.rb
#
# A short sample program demonstrating a UDP ping. You can run
# this program via the example:udp task. Modify as you see fit.
########################################################################
require 'net/ping'

host = 'www.google.com'

u = Net::Ping::UDP.new(host)
p u.ping?

I use the net-ping gem which you need to install. Then the code is easy:

#!/usr/bin/env ruby

require 'net/ping'

def up?(host)
    check = Net::Ping::External.new(host)
    check.ping?
end

chost = '10.0.0.1'
puts up?(chost) # prints "true" if ping replies