Class: Mixlib::ShellOut

### Home Classes Methods

### In Files

- lib/mixlib/shellout.rb
- lib/mixlib/shellout/exceptions.rb
- lib/mixlib/shellout/unix.rb
- lib/mixlib/shellout/version.rb
- lib/mixlib/shellout/windows.rb

### Parent

Object

### Namespace

- MODULE Mixlib::ShellOut::Unix
- MODULE Mixlib::ShellOut::Windows
- CLASS Mixlib::ShellOut::CommandTimeout
- CLASS Mixlib::ShellOut::InvalidCommandOption
- CLASS Mixlib::ShellOut::ShellCommandFailed

### Methods

- ::new
- #error!
- #error?
- #exitstatus
- #format_for_exception
- #gid
- #inspect
- #invalid!
- #live_stream
- #live_stream=
- #run_command
- #timeout
- #uid
- #umask=

### Included Modules

- Mixlib::ShellOut::Windows
- Mixlib::ShellOut::Unix

### Files

- LICENSE

### Class/Module Index

Quicksearch

- Mixlib
- Mixlib::ShellOut
- Mixlib::ShellOut::CommandTimeout
- Mixlib::ShellOut::InvalidCommandOption
- Mixlib::ShellOut::ShellCommandFailed
- Mixlib::ShellOut::Unix
- Mixlib::ShellOut::Windows
- Mixlib::ShellOut::Windows::ThingThatLooksSortOfLikeAProcessStatus
- Mixlib::ShellOut::Windows::Utils
- Process
- Process::Constants
- Process::Functions
- Process::Functions::FFI
- Process::Functions::FFI::Library

No matching classes.

# Mixlib::ShellOut

### Constants

DEFAULT_READ_TIMEOUT
READ_SIZE
READ_WAIT_TIME
VERSION

### Attributes

command[R]

The command to be executed.

cwd[RW]

Working directory for the subprocess. Normally set via options to new

domain[RW]
environment[RW]

Environment variables that will be set for the subcommand. Refer to the documentation of new to understand how ShellOut interprets this.

execution_time[R]

The amount of time the subcommand took to execute

group[RW]

Group the command will run as. Normally set via options passed to new

input[RW]

ShellOut will push data from :input down the stdin of the subprocss. Normally set via options passed to new. Default: nil

live_stderr[RW]

When live_stderr is set, the stderr of the subprocess will be copied to it as the subprocess is running.

live_stdout[RW]

When live_stdout is set, the stdout of the subprocess will be copied to it as the subprocess is running.

log_level[RW]

The log level at which ShellOut should log.

log_tag[RW]

A string which will be prepended to the log message.

logger[RW]

If a logger is set, ShellOut will log a message before it executes the command.

password[RW]
process_status_pipe[R]
status[R]

A Process::Status (or ducktype) object collected when the subprocess is reaped.

stderr[R]

Data written to stderr by the subprocess

stderr_pipe[R]
stdin_pipe[R]
stdout[R]

Data written to stdout by the subprocess

stdout_pipe[R]
timeout[W]

The maximum time this command is allowed to run. Usually set via options to new

umask[R]

The umask that will be set for the subcommand.

user[RW]

User the command will run as. Normally set via options passed to new

valid_exit_codes[RW]

An Array of acceptable exit codes. error? (and error!) use this list to determine if the command was successful. Normally set via options to new

with_logon[RW]

### Public Class Methods

new(*command_args) click to toggle source

### 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 to `user`

- `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 call `error!` after `run_command`.

- `environment`: a Hash of environment variables to set before the command is run.

- `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.

- `input`: A String of data to be passed to the subcommand. This is written to the child process' stdin stream before the process is launched. The child's stdin stream will be a pipe, so the size of input data should not exceed the system's default pipe capacity (4096 bytes is a safe value, though on newer Linux systems the capacity is 64k by default).

- `live_stream`: An IO or Logger-like object (must respond to the append operator +<<+) that will receive data as ShellOut reads it from the child process. Generally this is used to copy data from the child to the parent's stdout so that users may observe the progress of long-running commands.

### 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 157
    def initialize(*command_args)
      @stdout, @stderr, @process_status = '', '', ''
      @live_stdout = @live_stderr = nil
      @input = nil
      @log_level = :debug
      @log_tag = nil
      @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

error!() click to toggle source

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 264
    def error!
      invalid!("Expected process to exit with #{valid_exit_codes.inspect}, but received '#{exitstatus}'") if error?
    end

error?() click to toggle source

Checks the `exitstatus` against the set of `valid_exit_codes`.

### Returns

`true` if `exitstatus` is not in the list of `valid_exit_codes`, false otherwise.

    # File lib/mixlib/shellout.rb, line 255
    def error?
      !Array(valid_exit_codes).include?(exitstatus)
    end

exitstatus() click to toggle source

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 228
    def exitstatus
      @status && @status.exitstatus
    end

format_for_exception() click to toggle source

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 214
    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

gid() click to toggle source

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 202
    def gid
      return nil unless group
      group.kind_of?(Integer) ? group : Etc.getgrnam(group.to_s).gid
    end

inspect() click to toggle source

    # File lib/mixlib/shellout.rb, line 281
    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

invalid!(msg=nil) click to toggle source

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 276
    def invalid!(msg=nil)
      msg ||= "Command produced unexpected results"
      raise ShellCommandFailed, msg + "\n" + format_for_exception
    end

live_stream() click to toggle source

Returns the stream that both is being used by both live_stdout and live_stderr, or nil

    # File lib/mixlib/shellout.rb, line 176
    def live_stream
      live_stdout == live_stderr ? live_stdout : nil
    end

live_stream=(stream) click to toggle source

A shortcut for setting both live_stdout and live_stderr, so that both the stdout and stderr from the subprocess will be copied to the same stream as the subprocess is running.

    # File lib/mixlib/shellout.rb, line 183
    def live_stream=(stream)
      @live_stdout = @live_stderr = stream
    end

run_command() click to toggle source

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 243
    def run_command
      if logger
        log_message = (log_tag.nil? ? "" : "#@log_tag ") << "sh(#@command)"
        logger.send(log_level, log_message)
      end
      super
    end

timeout() click to toggle source

    # File lib/mixlib/shellout.rb, line 207
    def timeout
      @timeout || DEFAULT_READ_TIMEOUT
    end

uid() click to toggle source

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 195
    def uid
      return nil unless user
      user.kind_of?(Integer) ? user : Etc.getpwnam(user.to_s).uid
    end

umask=(new_umask) click to toggle source

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 189
    def umask=(new_umask)
      @umask = (new_umask.respond_to?(:oct) ? new_umask.oct : new_umask.to_i) & 007777
    end

[Validate]

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