device2yaml: add --newline option for quirky CLIs

CHANGELOG.md

@@ -6,6 +6,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/).
 
 ## [Unreleased]
 ### Added
+- device2yaml: add `-n`/`--newline` option to set the command line terminator (e.g. `-n "\r\n"`) for devices that submit a command only on a carriage return; the terminator is recorded as a `command_newline` key in the generated YAML (@Vantomas)
 
 ### Changed
 

docs/DeviceSimulation.md

@@ -60,6 +60,7 @@ Usages:
     -i, --input file                 Specify an input file for commands to be run
     -o, --output file                Specify an output YAML-file
     -t, --timeout value              Specify the idle timeout beween commands (default: 5 seconds)
+    -n, --newline value              Line terminator appended to each command (default: \n)
     -e, --exec-mode                  Run ssh in exec mode (without tty)
     -u, --unordered                  The YAML simulation should not enforce an order of the commands
     -h, --help                       Print this help
@@ -91,6 +92,11 @@ you will have to use the option `-e` to run `device2yaml.rb` in SSH exec mode.
   the model uses, use the option `-u`. Note that the `unordered` mode may not
   produce a useful YAML file when combined with user input (see
   [Interactive Mode](#interactive-mode) below).
+- Commands are terminated with `\n` by default. Some CLIs (e.g. TP-Link) execute
+  a command only on a carriage return; for those, set the line terminator with
+  `-n`/`--newline` (it understands the `\n`, `\r` and `\t` escapes), e.g.
+  `-n '\r\n'`. The chosen terminator is recorded in the YAML file as a
+  `command_newline` key, so it is clear how the simulation was captured.
 
 Note that `device2yaml.rb` takes some time to run because of the idle timeout of
 (default) 5 seconds between each command. You can press the "Escape" key if you

extra/device2yaml.rb

@@ -147,6 +147,12 @@ def cleanup
           'Specify the idle timeout beween commands (default: 5 seconds)') do |timeout|
     options[:timeout] = timeout
   end
+  opts.on('-n', '--newline value',
+          'Line terminator appended to each command (default: \n). ' \
+          'Accepts the escapes \n, \r and \t, e.g. -n "\r\n" for ' \
+          'devices that submit a command only on a carriage return.') do |newline|
+    options[:newline] = newline.gsub('\n', "\n").gsub('\r', "\r").gsub('\t', "\t")
+  end
   opts.on('-e', '--exec-mode', 'Run ssh in exec mode (without tty)') { @exec_mode = true }
   opts.on('-u', '--unordered', 'The YAML simulation should not enforce an order of the commands') do
     @sequence_prepend_command = ''
@@ -194,8 +200,10 @@ def cleanup
 end
 
 puts "Running #{ssh_commands} on #{ssh_user}@#{ssh_host}"
-# Add \n to each command
-ssh_commands.map! { |s| s + "\n" }
+# Append the line terminator to each command (default "\n", overridable with -n
+# for devices that submit a command only on a carriage return)
+command_newline = options[:newline] || "\n"
+ssh_commands.map! { |s| s + command_newline }
 
 # Defaut idle timeout: 5 seconds, as tests showed that 2 seconds is too short
 @idle_timeout = options[:timeout] || 5
@@ -235,6 +243,10 @@ def cleanup
 
 # YAML begin of file
 @output&.puts '---'
+# Record the line terminator appended to each command, so it is clear how the
+# simulation was captured (some CLIs submit a command only on "\r"). Consumers
+# that don't need it (e.g. the model unit tests) simply ignore this key.
+@output&.puts "command_newline: #{command_newline.dump}"
 
 if @exec_mode
   # init prompt does not exist and is empty in exec mode