.. Copyright 2017 IBM Corp. and Inova Development Inc. .. .. Licensed under the Apache License, Version 2.0 (the "License"); .. you may not use this file except in compliance with the License. .. You may obtain a copy of the License at .. .. http://www.apache.org/licenses/LICENSE-2.0 .. .. Unless required by applicable law or agreed to in writing, software .. distributed under the License is distributed on an "AS IS" BASIS, .. WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. .. See the License for the specific language governing permissions and .. limitations under the License. .. .. index:: single: pywbemcli command line interface single: command line interface .. _`Pywbemcli command line interface`: Pywbemcli command line interface ================================ This section describes the command line interface of the pywbemcli command within the pywbemtools package. Pywbemcli provides a command line interface(CLI) interaction with WBEM servers. The command line can contain the following components: .. index:: pair: General Options; command components * **GENERAL-OPTIONS** - General options; they apply to all commands. See :ref:`Using the pywbemcli command line general options` for information on the pywbemcli general options. .. index:: pair: command components; command components * **COMMAND** - A name of a command which may consist of: * for commands that are defined within groups (ex. ``class find``). * (ex. ``class``) to show group help including list of command within the group. * for those commands that are not part of a group. For example ``repl`` and ``help`` that are not in any command group. .. index:: pair: command arguments; command components * **ARGS** - Arguments for a command. .. index:: pair: command interface; Command Options * **COMMAND-OPTIONS** - Options that apply only to a particular COMMAND. Options are prefixed with the characters ``-`` for the short form or ``--`` for the long form (ex. ``-n`` or ``--namespace``). The other components do not begin with ``-``. .. index:: pair: command groups; command interface Command groups are named after the objects the commands operate on (ex. ``class``, ``instance``, ``qualifier``, ``server``). Executing .. code-block:: text $ pywbemcli --help ... Commands: class Command group for CIM classes. ... returns the list of command groups under the title `COMMANDS`. Commands are named after actions on these objects (ex. ``get``, ``create``, ``delete``). The list of commands for each group is listed with the command `pywbemcli --help`. For example, the command: .. code-block:: text $ pywbemcli --output-format mof class get CIM_ManagedElement --namespace interop gets class ``CIM_ManagedElement`` in namespace ``interop`` and displays it in the MOF output format. The option ``--output-format`` is a general option and ``--namespace`` is a command option. .. index:: pair: tab-completion; auto-completion single: auto-suggestion Pywbemcli supports several modes of tab-completion, auto-completion suggestions depending on whether it is in command or interactive mode. This is detailed in the following sections. .. index:: single: Modes of operation .. _`Modes of operation`: Modes of operation ------------------ Pywbemcli supports two modes of operation: * `Command mode`_: Executing standalone non-interactive commands. * `Interactive mode`_: Invoking an interactive pywbemcli shell for typing pywbemcli commands. .. index:: pair: interactive mode; command modes .. index:: pair: interactive mode; modes of operation .. _`Command mode`: Command mode ------------ .. index:: command mode In command mode, the pywbemcli command performs its task and terminates like any other standalone non-interactive command. This mode is used when the pywbemcli command is invoked with a command or command group name and arguments/options: .. code-block:: text $ pywbemcli [GENERAL-OPTIONS] COMMAND [COMMAND-OPTIONS] [ARGS] The following example enumerates classes in the ``root/cimv2`` namespace of the WBEM server on ``localhost``: .. code-block:: text $ pywbemcli --server http://localhost --default-namespace root/cimv2 --user username class enumerate Enter password: . . . .. index:: pair: tab-completion; command mode pair: auto-completion; command mode In command mode, tab completion is also supported for some command shells, but must be enabled specifically for each shell. .. index:: pair: command mode; bash For example, with a bash shell, enter the following to enable tab completion of pywbemcli: .. code-block:: text $ eval "$(_PYWBEMCLI_COMPLETE=source pywbemcli)" Bash tab completion for ``pywbemcli`` is used like any other bash tab completion: .. code-block:: text $ pywbemcli -- ... $ pywbemcli ... $ pywbemcli class ... Pywbemcli uses the Python `click package `_ for its command line handling. See `Bash Complete in the Click documentation `_ for additional features of the Bash tab completion of pywbemcli. .. index:: pair: interactive mode; command modes .. index:: pair: interactive mode; modes of operation .. _`Interactive mode`: Interactive mode ---------------- In interactive mode (also known as :term:`REPL` mode), pywbem provides an interactive shell environment that allows typing pywbemcli commands, internal commands (for operating the pywbemcli shell), and external commands (that are executed in the standard shell of the user). This pywbemcli shell is started when the ``pywbemcli`` command is invoked without specifying any command group or command: .. code-block:: text $ pywbemcli [GENERAL-OPTIONS] pywbemcli> _ Alternatively, the pywbemcli shell can also be started by specifying the ``repl`` command: .. code-block:: text $ pywbemcli [GENERAL-OPTIONS] repl pywbemcli> _ The pywbemcli shell uses the prompt ``pywbemcli>``. The cursor is shown in the examples above as an underscore (``_``). The commands and options that can be typed in the pywbemcli shell are the rest of the command line that would follow the ``pywbemcli`` command in `command mode`_, as well as internal commands (for operating the pywbemcli shell), and external commands (that are executed in the standard shell of the user): .. code-block:: text pywbemcli> [GENERAL-OPTIONS] COMMAND [ARGS] [COMMAND-OPTIONS] where: COMMAND can be either a group name and a command (ex. class find or repl) pywbemcli> :INTERNAL-COMMAND pywbemcli> !EXTERNAL-COMMAND The following example starts a pywbemcli shell in interactive mode, executes several commands, and exits the shell: .. code-block:: text $ pywbemcli -s http://localhost -d root/cimv2 -u username pywbemcli> class enumerate --no . . . pywbemcli> class get CIM_System . . . pywbemcli> :q The pywbemcli shell command ``class get CIM_System`` in the example above has the same effect as the standalone command: .. code-block:: text $ pywbemcli -s http://localhost -d root/cimv2 -u username class get CIM_System . . . .. index:: pair: interactive mode; help The internal commands ``:?``, ``:h``, or ``:help`` display general help information for external and internal commands: .. code-block:: text > :help REPL help: External Commands: prefix external commands with "!" Internal Commands: prefix internal commands with ":" :?, :h, :help displays general help information :exit, :q, :quit exits the REPL .. index:: pair: interactive mode; exit In addition to using one of the internal exit commands shown in the help text above, you can also exit the pywbemcli shell by typing `Ctrl-D` (on Linux, OS-X and UNIX-like environments on Windows), or `Ctrl-C` (on native Windows). .. index:: pair: interactive mode; --help Typing ``--help`` or ``-h`` in the pywbemcli shell displays general help information for the pywbemcli commands which includes general options and a list of the supported command groups and commands without command group. .. code-block:: text $ pywbemcli pywbemcli> --help Usage: pywbemcli [GENERAL-OPTIONS] COMMAND [ARGS] [COMMAND-OPTIONS] . . . General Options: -n, --name NAME Use the WBEM server ... . . . Commands: class Command group for CIM classes. connection Command group for WBEM connection definitions. . . . The usage line in this help text shows the usage in command mode. In interactive mode, the ``pywbemcli`` word is omitted. .. index:: pair: interactive mode; command help Typing ``COMMAND --help``, or ``COMMAND -h`` in the pywbemcli shell displays help information for the specified pywbemcli command group, for example: .. code-block:: text pywbemcli> class --help Usage: pywbemcli [GENERAL-OPTIONS] class COMMAND [ARGS] [COMMAND-OPTIONS] . . . Command Options: -h, --help Show this message and exit. Commands: associators List the classes associated with a class. . . . .. index:: pair: tab-completion; interactive mode pair: auto-completion; interactive mode The pywbemcli shell in the interactive mode supports popup help text while for commands, arguments, and options typing, where the valid choices are shown based upon what was typed so far, and where an item from the popup list can be picked with or with the cursor keys. It can be used to select from the list of general options. In the following examples, an underscore ``_`` is shown as the cursor: .. code-block:: text pywbemcli> --_ --name Use the WBEM server defined by the WBEM connection ... --mock-server Use a mock WBEM server that is automatically ... --server Use the WBEM server at the specified URL with ... . . . pywbemcli> cl_ class .. index:: pair: command history; interactive mode The pywbemcli shell supports history across multiple invocations of the shell using , to step through the history line by line. .. index:: single: command history; search pair: interactive mode; command history A incremental search of the history can be initiated by entering followed by one or more characters that define the search. The search displays the last command containing the search string. This search string can be modified in place to change the search, returning the last command in the command history that contains the the string. , will find other commands in the history containing the same string. .. code-block:: text pywbemcli> (reverse-i-search)`': ENTER Characters CIM (reverse-i-search)`CIM': class get CIM_ManagedElement and find other commands containing of "CIM" (i-search)`get': instance get CIM_ComputerSystem.? Hit selects current found command pywbemcli> instance get CIM_ComputerSystem.? .. index:: pair: interactive mode; history file The pywbemcli history is stored in the user home directory, ``~/.pywbemcli_history``. .. index:: pair: interactive mode; auto-suggestion The pywbemcli interactive mode also supports automated parameter suggestions based on the pywbemcli history file which works with the auto completion described above. The input is compared to the history and when there is another entry starting with the given text, the completion will be shown as gray text behind the current input. Pressing the right arrow → or c-e will insert this suggestion. .. index:: pair: Error handling; exit codes .. _`Error handling`: Error handling -------------- .. index:: Exit codes Pywbemcli terminates with one of the following program exit codes: * **0 - Success**: The pywbemcli command has succeeded. * **1 - Error**: In such cases, pywbemcli aborts the requested operation and displays one or more human readable error messages on standard error. If this happens for a command entered in interactive mode, the pywbemcli shell is not terminated; only the command that failed is terminated. Examples for errors reported that way: * Local system issues, e.g. pywbemcli history file or term:`connections file` cannot be written to. * WBEM server access issues, e.g. pywbemcli cannot connect to or authenticate with the WBEM server. This includes CIM errors about failed authentication returned by the server. * WBEM server operation issues, e.g. pywbemcli attempts to retrieve an instance that does not exist, or the WBEM server encountered an internal error. This will mostly be caused by CIM errors returned by the server, but can also be caused by the pywbemcli code itself. * Programming errors in mock Python scripts (see: :ref:`Mock support overview`); the error message includes a Python traceback of the error. * **1 - Python traceback**: In such cases, pywbemcli terminates during its processing, and displays the Python stack traceback on standard error. If this happens for a command entered in interactive mode, the pywbemcli shell also terminates with a program exit code of 1. These Python tracebacks should never happen and are always considered a reason to open a bug in the `pywbemtools issue tracker `_. Note that an error message with a traceback from a mock Python script does not fall into this category and is an issue in that Python script and not in pywbemcli. * **2 - User error**: In such cases, pywbemcli terminates without even attempting to perform the requested operation, and displays one or more human readable error messages on standard error. If this happens for a command entered in interactive mode, the pywbemcli shell is not terminated; only the command that failed is terminated. Examples for user errors are a missing required command argument, the use of an invalid option, or an invalid option argument. * **2 - Help**: When help is requested (``--help``/``-h`` option or ``help command``), pywbemcli displays the requested help text on standard output and terminates. If this happens for a command entered in interactive mode, the pywbemcli shell is not terminated; only the command that displayed the help is terminated.