Capistrano 3 does not use command cap env shell anymore.
Now we should use cap env console
But it is not interactive and we can not use for example arrow keys for history or autocompletion on tab button
And what should I do?
I suggest to write your own little rake task to do it. Use readline gem
First of all thanks to follow materials:
https://thoughtbot.com/blog/tab-completion-in-gnu-readline-ruby-edition
How to write a Ruby command line app that supports tab completion?
desc "Remote console"
task :console do
require 'readline'
# https://thoughtbot.com/blog/tab-completion-in-gnu-readline-ruby-edition
host_args = (ENV['HOSTS'] || '').split(',').map { |r| r.to_sym }
role_args = (ENV['ROLES'] || '').split(',').map { |r| r.to_sym }
LIST = `ls /usr/bin`.split("\n").sort + `ls /bin`.split("\n").sort
comp = proc { |s| LIST.grep(/^#{Regexp.escape(s)}/) }
Readline.completion_append_character = " "
Readline.completion_proc = comp
while line = Readline.readline('cap> ', true)
begin
next if line.strip.empty?
exec_cmd(line, host_args, role_args)
rescue StandardError => e
puts e
puts e.backtrace
end
end
end
def exec_cmd(line, host_args, role_args)
line = "RAILS_ENV=#{fetch(:stage)} #{line}" if fetch(:stage)
cmd = "bash -lc '#{line}'"
puts "Final command: #{cmd}"
if host_args.any?
on hosts host_args do
execute cmd
end
elsif role_args.any?
on roles role_args do
execute cmd
end
else
on roles :all do
execute cmd
end
end
end
And do what you want with it, cheers! =))
Related
I have done a program that sends requests to a url and saves them in a file. The program is this, and is working perfectly:
require 'open-uri'
n = gets.to_i
out = gets.chomp
output = File.open( out, "w" )
for i in 1..n
response = open('http://slowapi.com/delay/10').read
output << (response +"\n")
puts response
end
output.close
I want to modify it so that I can execute it from command line. I must run it like this:
fle --test abc -n 300 -f output
What must I do?
Something like this should do the trick:
#!/usr/bin/env ruby
require 'open-uri'
require 'optparse'
# Prepare the parser
options = {}
oparser = OptionParser.new do |opts|
opts.banner = "Usage: fle [options]"
opts.on('-t', '--test [STRING]', 'Test string') { |v| options[:test] = v }
opts.on('-n', '--count COUNT', 'Number of times to send request') { |v| options[:count] = v.to_i }
opts.on('-f', '--file FILE', 'Output file', :REQUIRED) { |v| options[:out_file] = v }
end
# Parse our options
oparser.parse! ARGV
# Check if required options have been filled, print help and exit otherwise.
if options[:count].nil? || options[:out_file].nil?
$stderr.puts oparser.help
exit 1
end
File::open(options[:out_file], 'w') do |output|
options[:count].times do
response = open('http://slowapi.com/delay/10').read
output.puts response # Puts the response into the file
puts response # Puts the response to $stdout
end
end
Here's a more idiomatic way of writing your code:
require 'open-uri'
n = gets.to_i
out = gets.chomp
File.open(out, 'w') do |fo|
n.times do
response = open('http://slowapi.com/delay/10').read
fo.puts response
puts response
end
end
This uses File.open with a block, which allows Ruby to close the file once the block exits. It's a much better practice than assigning the file handle to a variable and use that to close the file later.
How to handle passing in variables from the command-line as options is handled in the other answers.
The first step would be to save you program in a file, add #!/usr/bin/env ruby at the top and chmod +x yourfilename to be able to execute your file.
Now you are able to run your script from the command line.
Secondly, you need to modify your script a little bit to pick up command line arguments. In Ruby, the command line arguments are stored inside ARGV, so something like
ARGV.each do|a|
puts "Argument: #{a}"
end
allows you to retrieve command line arguments.
I want to bulid a multi threaded application. If i do not use threads, everything works fine. When i try to use threads, then nothing is displayed on the browser. when i use the syntax 'puts "%s" %io.read' then it displays on the command prompt and not on the browser. Any help would be appreciated.
require 'sinatra'
require 'thread'
set :environment, :production
get '/price/:upc/:rtype' do
Webupc = "#{params[:upc]}"
Webformat = "#{params[:rtype]}"
MThread = Thread.new do
puts "inside thread"
puts "a = %s" %Webupc
puts "b = %s" %Webformat
#call the price
Maxupclen = 16
padstr = ""
padupc = ""
padlen = (Maxupclen - Webupc.length)
puts "format type: #{params[:rtype]}"
puts "UPC: #{params[:upc]}"
puts "padlen: %s" %padlen
if (Webformat == 'F')
puts "inside format"
if (padlen == 0 ) then
IO.popen("tstprcpd.exe #{Webupc}")
{ |io|
"%s" %io.read
}
elsif (padlen > 0 ) then
for i in 1 .. padlen
padstr = padstr + "0"
end
padupc = padstr + Webupc
puts "padupc %s" %padupc
IO.popen("tstprcpd.exe #{padupc}") { |io|
"%s" %io.read
}
elsif (padlen < 0 ) then
IO.popen("date /T") { |io|
"UPC length must be 16 digits or less." %io.read
}
end
end
end
end
Your code has several problems:
It is not formatted properly
You are using Uppercase names for variables; that makes them constants!
puts will not output to the browser, but to the console. The browser will recieve the return value of the block, i.e. the return value of the last statement in the block. Therefore, you need to build your output differently (see below).
You are never joining the thread
Here's a minimal sinatra app that uses a thread. However, the thread makes no sense in this case because you must wait for its termination anyway before you can output the result to the browser. In order to build the output I have used StringIO, which you can use with puts to build a multiline string conveniently. However, you could also simply initialize res with an empty string with res = "" and then append your lines to this string with res << "new line\n".
require 'sinatra'
require 'thread'
require 'stringio'
get '/' do
res = StringIO.new
th = Thread.new do
res.puts 'Hello, world!'
end
th.join
res.string
end
I have a Ruby app which uses readline with command completion.
After the first string (the command) was typed, I would like to be able to complete its arguments. The arguments list should be based on the chosen command.
Does someone have a quick example?
These are the commands:
COMMANDS = [
'collect', 'watch'
].sort
COLLECT = [
'stuff', 'otherstuff'
].sort
comp = proc do |s|
COMMANDS.grep( /^#{Regexp.escape(s)}/ )
end
Readline.completion_proc = comp
Each time I press TAB, the proc block is executed and a command from the COMMANDS array is matched.
After one of the commands was fully matched I would like to start searching for the argument only in the COLLECT array.
Since your question popped up first every time I looked for something like this I want to share my code for any one else.
#!/usr/bin/env ruby
require 'readline'
module Shell
PROMPT = "shell> "
module InputCompletor
CORE_WORDS = %w[ clear help show exit export]
SHOW_ARGS = %w[ list user ]
EXPORT_ARGS = %w[ file ]
COMPLETION_PROC = proc { |input|
case input
when /^(show|export) (.*)/
command = $1
receiver = $2
DISPATCH_TABLE[$1].call($2)
when /^(h|s|c|e.*)/
receiver = $1
CORE_WORDS.grep(/^#{Regexp.quote(receiver)}/)
when /^\s*$/
puts
CORE_WORDS.map{|d| print "#{d}\t"}
puts
print PROMPT
end
}
def self.show(receiver)
if SHOW_ARGS.grep(/^#{Regexp.quote(receiver)}/).length > 1
SHOW_ARGS.grep(/^#{Regexp.quote(receiver)}/)
elsif SHOW_ARGS.grep(/^#{Regexp.quote(receiver)}/).length == 1
"show #{SHOW_ARGS.grep(/^#{Regexp.quote(receiver)}/).join}"
end
end
def self.export(receiver)
if EXPORT_ARGS.grep(/^#{Regexp.quote(receiver)}/).length > 1
EXPORT_ARGS.grep(/^#{Regexp.quote(receiver)}/)
elsif EXPORT_ARGS.grep(/^#{Regexp.quote(receiver)}/).length == 1
"export #{EXPORT_ARGS.grep(/^#{Regexp.quote(receiver)}/).join}"
end
end
DISPATCH_TABLE = {'show' => lambda {|x| show(x)} ,
'export' => lambda {|x| export(x)}}
end
class CLI
Readline.completion_append_character = ' '
Readline.completer_word_break_characters = "\x00"
Readline.completion_proc = Shell::InputCompletor::COMPLETION_PROC
def initialize
while line = Readline.readline("#{PROMPT}",true)
Readline::HISTORY.pop if /^\s*$/ =~ line
begin
if Readline::HISTORY[-2] == line
Readline::HISTORY.pop
end
rescue IndexError
end
cmd = line.chomp
case cmd
when /^clear/
system('clear')
when /^help/
puts 'no help here'
when /show list/
puts 'nothing to show'
when /^show\s$/
puts 'missing args'
when /export file/
puts 'nothing to export'
when /^export\s$/
puts 'missing args'
when /^exit/
exit
end
end
end
end
end
Shell::CLI.new
After thinking a while, the solution was very simple:
comp = proc do |s|
if Readline.line_buffer =~ /^.* /
COLLECT.grep( /^#{Regexp.escape(s)}/ )
else
COMMANDS.grep( /^#{Regexp.escape(s)}/ )
end
end
Now I just need to turn it into something more flexible/usable.
I've put this together through scripts that I have found online, but I'm not sure why my puts command is not performing a system command? It just sits in the terminal unexecuted. When I tried system ("rspec spec") it worked but I wasn't able to capture the output.
def run(cmd)
`#{cmd}`
end
def run_spec_files
system('clear')
result = "rspec spec"
puts result
growl(result)
end
def growl(message)
growlnotify = `which growlnotify`.chomp
unless growlnotify.empty?
title = "Test Results"
options = "-w -n Watchr -m '#{message}' '#{title}'"
run("#{growlnotify} #{options} &")
end
end
watch( 'lib/(.*)\.rb' ) { run_spec_files }
puts Just prints out the string you pass it. It doesn't execute it in a shell. Backticks like in your run method will execute on the shell. Try this:
def run_spec_files
system('clear')
result = run("rspec spec")
puts result
growl(result)
end
I've got a script thats supposed to mimic ffmpeg on my local machine, by sending the command of to a remote machine, running it there and then returning the results.
(see previous stackoverflow question.)
#!/usr/bin/env ruby
require 'rubygems'
require 'net/ssh'
require 'net/sftp'
require 'highline/import'
file = ARGV[ ARGV.index( '-i' ) + 1] if ARGV.include?( '-i' )
puts 'No input file specified' unless file;
host = "10.0.0.10"
user = "user"
prod = "new-#{file}" # product filename (call it <file>-new)
rpath = "/home/#{user}/.rffmpeg" # remote computer operating directory
rfile = "#{rpath}/#{file}" # remote filename
rprod = "#{rpath}/#{prod}" # remote product
cmd = "ffmpeg -i #{rfile} #{rprod}"# remote command, constructed
pass = ask("Password: ") { |q| q.echo = false } # password from stdin
Net::SSH.start(host, user ) do |ssh|
ssh.sftp.connect do |sftp|
# upload local 'file' to remote 'rfile'
sftp.upload!(file, rfile)
# run remote command 'cmd' to produce 'rprod'
ssh.exec!(cmd)
# download remote 'rprod' to local 'prod'
sftp.download!(rprod, prod)
end
end
now my problem is at
ssh.exec!(cmd)
I want to display the cmd's output to the local user in real-time. But making it
puts ssh.exec!(cmd)
I only get the resulting output after the command has finished running. How would I have to change the code to make this work?
On the display side of your question, you can generate an updating progress bar in Ruby using the "\r" string char. This backs you up to the beginning of the current line allowing you to re-write it. For example:
1.upto(100) { |i| sleep 0.05; print "\rPercent Complete #{i}%"}
Or if you just want a progress bar across the screen you can simply do something similar to this:
1.upto(50) { sleep 0.05; print "|"}
Also, relating to stdout, in addition to flushing output per previous example (STDOUT.flush), you can ask Ruby to automatically sync writes to an IO buffer (in this case STDOUT) with associated device writes (basically turns off internal buffering):
STDOUT.sync = true
Also, I find that sometimes flush doesn't work for me, and I use "IO.fsync" instead. For me that's mostly been related to file system work, but it's worth knowing.
From ri Net::SSH::start:
-------------------------------------------------------- Net::SSH::start
Net::SSH::start(host, user, options={}, &block) {|connection| ...}
------------------------------------------------------------------------
The standard means of starting a new SSH connection. When used with
a block, the connection will be closed when the block terminates,
otherwise the connection will just be returned. The yielded (or
returned) value will be an instance of
Net::SSH::Connection::Session (q.v.). (See also
Net::SSH::Connection::Channel and Net::SSH::Service::Forward.)
Net::SSH.start("host", "user") do |ssh|
ssh.exec! "cp /some/file /another/location"
hostname = ssh.exec!("hostname")
ssh.open_channel do |ch|
ch.exec "sudo -p 'sudo password: ' ls" do |ch, success|
abort "could not execute sudo ls" unless success
ch.on_data do |ch, data|
print data
if data =~ /sudo password: /
ch.send_data("password\n")
end
end
end
end
ssh.loop
end
So it looks like you can get more interactive by using #open_channel
Here's some example code:
user#server% cat echo.rb
#! /usr/local/bin/ruby
def putsf s
puts s
STDOUT.flush
end
putsf "hello"
5.times do
putsf gets.chomp
end
putsf "goodbye"
And on your local machine:
user#local% cat client.rb
#! /usr/local/bin/ruby
require 'rubygems'
require 'net/ssh'
words = %w{ earn more sessions by sleaving }
index = 0;
Net::SSH.start('server', 'user') do |ssh|
ssh.open_channel do |ch|
ch.exec './echo.rb' do |ch, success|
abort "could not execute ./echo.rb" unless success
ch.on_data do |ch, data|
p [:data, data]
index %= words.size
ch.send_data( words[index] + "\n" )
index += 1
end
end
end
end
user#local% ./client.rb
[:data, "hello\n"]
[:data, "earn\n"]
[:data, "more\n"]
[:data, "sessions\n"]
[:data, "by\n"]
[:data, "sleaving\n"]
[:data, "goodbye\n"]
So you can interact with a running process this way.
It's important that the running process flush its output before requesting input - otherwise, the program might hang as the channel may not have received the unflushed output.