output.txt

C:\Source\tmp\process_spawn> be ruby test.rb                                                                                                        
*** back ticks
hello " world

*** %x
hello " world

*** capture3
hello "\"" world

*** process.spawn
hello "\"" world

*** capture3 using Array,Array
hello "\"" world

*** capture3 using Array,String
hello \" world

*** capture3 testcases
Expect:hello world
Actual:hello world

Expect:hello " world
Actual:hello "\"" world

Expect: hello   "   world
Actual:" hello " " \" " " world "

Expect:hello "" world
Actual:hello "\"\"" world

Expect:hello \" world
Actual:hello "\\\"" world

Expect:hello ^" world
Actual:hello "^\"" world

C:\Source\tmp\process_spawn>

test.rb

require 'open3'

shell = ['cmd.exe', '/c']
command = ['echo', 'hello', '"', 'world']

#Output

# cmd.exe
# C:\Users\glenn.sarti>echo hello " world
# hello " world

# PowerShell
# C:\Source\tmp\process_spawn> cmd --% /c echo hello " world
# hello " world

puts "\n*** back ticks"
puts `#{shell.join(' ')} #{command.join(' ')}`
# hello " world

puts "\n*** %x"
puts %x[#{shell.join(' ')} #{command.join(' ')}]


puts "\n*** capture3"
cmd = shell.dup.concat(command)
stdout, stderr, t = Open3.capture3(*cmd)
puts stdout

puts "\n*** process.spawn"
cmd = shell.dup.concat(command)
tmpfile = File.join(ENV['TMP'], 'stdout.txt')
pid = Process.spawn(*cmd, :out => tmpfile)
Process.wait pid
File.open(tmpfile, 'rb') { |f| puts f.read }

puts "\n*** capture3 using Array,Array"
cmd = shell.dup.concat(command)
stdout, stderr, t = Open3.capture3(*shell, *command)
puts stdout

puts "\n*** capture3 using Array,String"
cmd = shell.dup
cmd << command.join(' ')
stdout, stderr, t = Open3.capture3(*cmd)
puts stdout

# ---

puts "\n*** capture3 testcases"
[
  ['hello', 'world'],
  ['hello', '"', 'world'],
  [' hello ', ' " ', ' world '],
  ['hello', '""', 'world'],
  ['hello', '\\"', 'world'],
  ['hello', '^"', 'world'],
].each do |testcase|
  cmd = shell.dup.concat(['echo']).concat(testcase)
  stdout, stderr, t = Open3.capture3(*cmd)
  puts "Expect:#{testcase.join(' ')}\nActual:#{stdout}\n"
end

# Looked at raw FFI...but too hard right now