Class: MiniMagick::Shell

Inherits:
Object
  • Object
show all
Defined in:
lib/mini_magick/shell.rb

Overview

Sends commands to the shell (more precisely, it sends commands directly to the operating system).

Instance Method Summary collapse

Instance Method Details

#execute(command, stdin: "", timeout: MiniMagick.timeout) ⇒ Object 



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# File 'lib/mini_magick/shell.rb', line 28

def execute(command, stdin: "", timeout: MiniMagick.timeout)
  env = MiniMagick.restricted_env ? ENV.to_h.slice("HOME", "PATH", "LANG") : {} # Using #to_h for Ruby 2.5 compatibility.
  env.merge!(MiniMagick.cli_env)
  env["MAGICK_TIME_LIMIT"] = timeout.to_s if timeout

  stdout, stderr, status = log(command.join(" ")) do
    # We would ideally use Open3.capture3, but it doesn't allow us to
    # terminate the command after timing out. We can't rely solely on
    # ImageMagick's own $MAGICK_TIME_LIMIT for this, because it's only
    # checked periodically inside ImageMagick's processing loops, so it
    # can fire too late (or not at all) depending on the operation.
    Open3.popen3(env, *command, unsetenv_others: MiniMagick.restricted_env) do |stdin_io, stdout_io, stderr_io, wait_thread|
      stdin_io.binmode
      stdout_io.binmode
      stderr_io.binmode

      stdout_reader = Thread.new { stdout_io.read }
      stderr_reader = Thread.new { stderr_io.read }

      begin
        stdin_io.write(stdin)
      rescue Errno::EPIPE
      end
      stdin_io.close

      if timeout && !wait_thread.join(timeout)
        Process.kill("TERM", wait_thread.pid) rescue nil
        wait_thread.join
        fail MiniMagick::TimeoutError, "`#{command.join(" ")}` has timed out"
      end

      [stdout_reader.value, stderr_reader.value, wait_thread.value]
    end
  end

  [stdout, stderr, status&.exitstatus]
rescue Errno::ENOENT, IOError
  ["", "executable not found: \"#{command.first}\"", 127]
end

#run(command, errors: MiniMagick.errors, warnings: MiniMagick.warnings, **options) ⇒ Object 



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# File 'lib/mini_magick/shell.rb', line 12

def run(command, errors: MiniMagick.errors, warnings: MiniMagick.warnings, **options)
  stdout, stderr, status = execute(command, **options)

  if status != 0
    if stderr.include?("time limit exceeded")
      fail MiniMagick::TimeoutError, "`#{command.join(" ")}` has timed out"
    elsif errors
      fail MiniMagick::Error, "`#{command.join(" ")}` failed with status: #{status.inspect} and error:\n#{stderr}"
    end
  end

  $stderr.print(stderr) if warnings

  [stdout, stderr, status]
end