class Mixlib::ShellOut
Constants
- DEFAULT_ENVIRONMENT
- DEFAULT_READ_TIMEOUT
- READ_SIZE
- READ_WAIT_TIME
- VERSION
Attributes
The command to be executed.
Working directory for the subprocess. Normally set via options to new
Environment variables that will be set for the subcommand. Refer to the documentation of new to understand how ShellOut interprets this.
The amount of time the subcommand took to execute
Group the command will run as. Normally set via options passed to new
ShellOut will push data from :input down the stdin of the subprocss. Normally set via options passed to new. Default: nil
When #live_stream is set, stdout of the subprocess will be copied to it as the subprocess is running. For example, if #live_stream is set to STDOUT, the command's output will be echoed to STDOUT.
The log level at which ShellOut should log.
A string which will be prepended to the log message.
If a logger is set, ShellOut will log a message before it executes the command.
A Process::Status (or ducktype) object collected when the subprocess is reaped.
Data written to stderr by the subprocess
Data written to stdout by the subprocess
The maximum time this command is allowed to run. Usually set via options to new
The umask that will be set for the subcommand.
User the command will run as. Normally set via options passed to new
Public Class Methods
Arguments:¶ ↑
Takes a single command, or a list of command fragments. These are used as arguments to Kernel.exec. See the Kernel.exec documentation for more explanation of how arguments are evaluated. The last argument can be an options Hash.
Options:¶ ↑
If the last argument is a Hash, it is removed from the list of args passed to exec and used as an options hash. The following options are available:
-
user
: the user the commmand should run as. if an integer is given, it is used as a uid. A string is treated as a username and resolved to a uid with Etc.getpwnam -
group
: the group the command should run as. works similarly touser
-
cwd
: the directory to chdir to before running the command -
umask
: a umask to set before running the command. If given as an Integer, be sure to use two leading zeros so it's parsed as Octal. A string will be treated as an octal integer -
returns
: one or more Integer values to use as valid exit codes for the subprocess. This only has an effect if you callerror!
afterrun_command
. -
environment
: a Hash of environment variables to set before the command is run. By default, the environment will always be set to 'LC_ALL' => 'C' to prevent issues with multibyte characters in Ruby 1.8. To avoid this, use :environment => nil for no extra environment settings, or :environment => {'LC_ALL'=>nil, …} to set other environment settings without changing the locale. -
timeout
: a Numeric value for the number of seconds to wait on the child process before raising an Exception. This is calculated as the total amount of time that ShellOut waited on the child process without receiving any output (i.e., IO.select returned nil). Default is 60 seconds. Note: the stdlib Timeout library is not used.
Examples:¶ ↑
Invoke find(1) to search for .rb files:
find = Mixlib::ShellOut.new("find . -name '*.rb'") find.run_command # If all went well, the results are on +stdout+ puts find.stdout # find(1) prints diagnostic info to STDERR: puts "error messages" + find.stderr # Raise an exception if it didn't exit with 0 find.error!
Run a command as the www
user with no extra ENV settings from
/tmp
cmd = Mixlib::ShellOut.new("apachectl", "start", :user => 'www', :env => nil, :cwd => '/tmp') cmd.run_command # etc.
# File lib/mixlib/shellout.rb, line 148 def initialize(*command_args) @stdout, @stderr = '', '' @live_stream = nil @input = nil @log_level = :debug @log_tag = nil @environment = DEFAULT_ENVIRONMENT @cwd = nil @valid_exit_codes = [0] @terminate_reason = nil if command_args.last.is_a?(Hash) parse_options(command_args.pop) end @command = command_args.size == 1 ? command_args.first : command_args end
Public Instance Methods
If error? is true, calls
invalid!
, which raises an Exception.
Returns¶ ↑
- nil:
-
always returns nil when it does not raise
Raises¶ ↑
- ::ShellCommandFailed:
-
via
invalid!
# File lib/mixlib/shellout.rb, line 243 def error! invalid!("Expected process to exit with #{valid_exit_codes.inspect}, but received '#{exitstatus}'") if error? end
The exit status of the subprocess. Will be nil if the command is still running or died without setting an exit status (e.g., terminated by `kill -9`).
# File lib/mixlib/shellout.rb, line 207 def exitstatus @status && @status.exitstatus end
Creates a String showing the output of the command, including a banner
showing the exact command executed. Used by invalid!
to show
command results when the command exited with an unexpected status.
# File lib/mixlib/shellout.rb, line 193 def format_for_exception msg = "" msg << "#{@terminate_reason}\n" if @terminate_reason msg << "---- Begin output of #{command} ----\n" msg << "STDOUT: #{stdout.strip}\n" msg << "STDERR: #{stderr.strip}\n" msg << "---- End output of #{command} ----\n" msg << "Ran #{command} returned #{status.exitstatus}" if status msg end
The gid that the subprocess will switch to. If the group attribute is given as a group name, it is converted to a gid by Etc.getgrnam
# File lib/mixlib/shellout.rb, line 181 def gid return nil unless group group.kind_of?(Integer) ? group : Etc.getgrnam(group.to_s).gid end
# File lib/mixlib/shellout.rb, line 260 def inspect "<#{self.class.name}##{object_id}: command: '#@command' process_status: #{@status.inspect} " + "stdout: '#{stdout.strip}' stderr: '#{stderr.strip}' child_pid: #{@child_pid.inspect} " + "environment: #{@environment.inspect} timeout: #{timeout} user: #@user group: #@group working_dir: #@cwd >" end
Raises a ShellCommandFailed exception, appending the command's stdout, stderr, and exitstatus to the exception message.
Arguments¶ ↑
msg
: A String to use as the basis of the exception message.
The default explanation is very generic, providing a more informative
message is highly encouraged.
Raises¶ ↑
ShellCommandFailed always
# File lib/mixlib/shellout.rb, line 255 def invalid!(msg=nil) msg ||= "Command produced unexpected results" raise ShellCommandFailed, msg + "\n" + format_for_exception end
Run the command, writing the command's standard out and standard error
to stdout
and stderr
, and saving its exit status
object to status
Returns¶ ↑
returns self
; stdout
, stderr
,
status
, and exitstatus
will be populated with
results of the command
Raises¶ ↑
-
Errno::EACCES when you are not privileged to execute the command
-
Errno::ENOENT when the command is not available on the system (or not in the current $PATH)
-
CommandTimeout when the command does not complete within
timeout
seconds (default: 600s)
# File lib/mixlib/shellout.rb, line 222 def run_command if logger log_message = (log_tag.nil? ? "" : "#@log_tag ") << "sh(#@command)" logger.send(log_level, log_message) end super end
# File lib/mixlib/shellout.rb, line 186 def timeout @timeout || DEFAULT_READ_TIMEOUT end
The uid that the subprocess will switch to. If the user attribute was given as a username, it is converted to a uid by Etc.getpwnam
# File lib/mixlib/shellout.rb, line 174 def uid return nil unless user user.kind_of?(Integer) ? user : Etc.getpwnam(user.to_s).uid end
Set the umask that the subprocess will have. If given as a string, it will be converted to an integer by String#oct.
# File lib/mixlib/shellout.rb, line 168 def umask=(new_umask) @umask = (new_umask.respond_to?(:oct) ? new_umask.oct : new_umask.to_i) & 007777 end
Private Instance Methods
# File lib/mixlib/shellout.rb, line 268 def parse_options(opts) opts.each do |option, setting| case option.to_s when 'cwd' self.cwd = setting when 'domain' self.domain = setting when 'password' self.password = setting when 'user' self.user = setting self.with_logon = setting when 'group' self.group = setting when 'umask' self.umask = setting when 'timeout' self.timeout = setting when 'returns' self.valid_exit_codes = Array(setting) when 'live_stream' self.live_stream = setting when 'input' self.input = setting when 'logger' self.logger = setting when 'log_level' self.log_level = setting when 'log_tag' self.log_tag = setting when 'environment', 'env' # Set the LC_ALL from the parent process if the user wanted # to use the default. if setting && setting.has_key?("LC_ALL") && setting['LC_ALL'].nil? setting['LC_ALL'] = ENV['LC_ALL'] end # passing :environment => nil means don't set any new ENV vars @environment = setting.nil? ? {} : @environment.dup.merge!(setting) else raise InvalidCommandOption, "option '#{option.inspect}' is not a valid option for #{self.class.name}" end end validate_options(opts) end
# File lib/mixlib/shellout.rb, line 315 def validate_options(opts) super end