Cmd2

- Bug Fixes
- Fixed issue where the wrong terminator was being appended by `Statement.expanded_command_line()`
- Fixed issue where aliases and macros could not contain terminator characters in their values
- History now shows what was typed for macros and not the resolved value by default. This is consistent with
the behavior of aliases. Use the `expanded` or `verbose` arguments to `history` to see the resolved value for
the macro.
- Fixed parsing issue in case where output redirection appears before a pipe. In that case, the pipe was given
precedence even though it appeared later in the command.
- Fixed issue where quotes around redirection file paths were being lost in `Statement.expanded_command_line()`
- Fixed a bug in how line numbers were calculated for transcript testing
- Fixed issue where `_cmdloop()` suppressed exceptions by returning from within its `finally` code
- Fixed UnsupportedOperation on fileno error when a shell command was one of the commands run while generating
a transcript
- Fixed bug where history was displaying expanded multiline commands when -x was not specified
- Enhancements
- **Added capability to chain pipe commands and redirect their output (e.g. !ls -l | grep user | wc -l > out.txt)**
- `pyscript` limits a command's stdout capture to the same period that redirection does.
Therefore output from a command's postparsing and finalization hooks isn't saved in the StdSim object.
- `StdSim.buffer.write()` now flushes when the wrapped stream uses line buffering and the bytes being written
contain a newline or carriage return. This helps when `pyscript` is echoing the output of a shell command
since the output will print at the same frequency as when the command is run in a terminal.
- **ACArgumentParser** no longer prints complete help text when a parsing error occurs since long help messages
scroll the actual error message off the screen.
- Exceptions occurring in tab completion functions are now printed to stderr before returning control back to
readline. This makes debugging a lot easier since readline suppresses these exceptions.
- Added support for custom Namespaces in the argparse decorators. See description of `ns_provider` argument
for more information.
- Transcript testing now sets the `exit_code` returned from `cmdloop` based on Success/Failure
- The history of entered commands previously was saved using the readline persistence mechanism,
and only persisted if you had readline installed. Now history is persisted independent of readline; user
input from previous invocations of `cmd2` based apps now shows in the `history` command.
- Text scripts now run immediately instead of adding their commands to `cmdqueue`. This allows easy capture of
the entire script's output.
- Added member to `CommandResult` called `stop` which is the return value of `onecmd_plus_hooks` after it runs
the given command line.
- Breaking changes
- Replaced `unquote_redirection_tokens()` with `unquote_specific_tokens()`. This was to support the fix
that allows terminators in alias and macro values.
- Changed `Statement.pipe_to` to a string instead of a list
- `preserve_quotes` is now a keyword-only argument in the argparse decorators
- Refactored so that `cmd2.Cmd.cmdloop()` returns the `exit_code` instead of a call to `sys.exit()`
It is now application developer's responsibility to treat the return value from `cmdloop()` accordingly
- Only valid commands are persistent in history between invocations of `cmd2` based apps. Previously
all user input was persistent in history. If readline is installed, the history available with the up and
down arrow keys (readline history) may not match that shown in the `history` command, because `history`
only tracks valid input, while readline history captures all input.
- History is now persisted in a binary format, not plain text format. Previous history files are destroyed
on first launch of a `cmd2` based app of version 0.9.13 or higher.
- HistoryItem class is no longer a subclass of `str`. If you are directly accessing the `.history` attribute
of a `cmd2` based app, you will need to update your code to use `.history.get(1).statement.raw` instead.
- Removed internally used `eos` command that was used to keep track of when a text script's commands ended
- Removed `cmd2` member called `_STOP_AND_EXIT` since it was just a boolean value that should always be True
- Removed `cmd2` member called `_should_quit` since `PyBridge` now handles this logic
- Removed support for `cmd.cmdqueue`
- `allow_cli_args` is now an argument to **init** instead of a `cmd2` class member
- **Python 3.4 EOL notice**
- Python 3.4 reached its [end of life](https://www.python.org/dev/peps/pep-0429/) on March 18, 2019
- This is the last release of `cmd2` which will support Python 3.4

- Bug Fixes
- Fixed a bug in how redirection and piping worked inside `py` or `pyscript` commands
- Fixed bug in `async_alert` where it didn't account for prompts that contained newline characters
- Fixed path completion case when CWD is just a slash. Relative path matches were incorrectly prepended with a slash.
- Enhancements
- Added ability to include command name placeholders in the message printed when trying to run a disabled command.
- See docstring for `disable_command()` or `disable_category()` for more details.
- Added instance attributes to customize error messages without having to override methods. These messages can
also be colored.
_ `help_error` - the error that prints when no help information can be found
_ `default_error` - the error that prints when a non-existent command is run
- The `with_argparser` decorators now add the Statement object created when parsing the command line to the
`argparse.Namespace` object they pass to the `do_*` methods. It is stored in an attribute called `__statement__`.
This can be useful if a command function needs to know the command line for things like logging.
- Added a `-t` option to the `load` command for automatically generating a transcript based on a script file
- When in a **pyscript**, the stdout and stderr streams of shell commands and processes being piped to are now
captured and included in the `CommandResult` structure.
- Potentially breaking changes
- The following commands now write to stderr instead of stdout when printing an error. This will make catching
errors easier in pyscript.
_ `do_help()` - when no help information can be found
_ `default()` - in all cases since this is called when an invalid command name is run \* `_report_disabled_command_usage()` - in all cases since this is called when a disabled command is run
- Removed \*\*\* from beginning of error messages printed by `do_help()` and `default()`
- Significantly refactored `cmd.Cmd` class so that all class attributes got converted to instance attributes, also:
- Added `allow_redirection`, `terminators`, `multiline_commands`, and `shortcuts` as optional arguments
to `cmd2.Cmd.__init__()`
- A few instance attributes were moved inside `StatementParser` and properties were created for accessing them
- `self.pipe_proc` is now called `self.cur_pipe_proc_reader` and is a `ProcReader` class.
- Shell commands and commands being piped to while in a _pyscript_ will function as if their output is going
to a pipe and not a tty. This was necessary to be able to capture their output.
- Removed `reserved_words` class attribute due to lack of use
- Removed `keywords` instance attribute due to lack of use

- Bug Fixes
- Fixed bug in how **history** command deals with multiline commands when output to a script
- Fixed a bug when the `with_argument_list` decorator is called with the optional `preserve_quotes` argument
- Fix bug in `perror()` where it would try to print an exception Traceback even if none existed
- Enhancements
- Improvements to the **history** command
- Simplified the display format and made it more similar to **bash**
- Added **-x**, **--expanded** flag
- output expanded commands instead of entered command (expands aliases, macros, and shortcuts)
- Added **-v**, **--verbose** flag
- display history and include expanded commands if they differ from the typed command
- Added support for negative indices
- Added `matches_sort_key` to override the default way tab completion matches are sorted
- Added `StdSim.pause_storage` member which when True will cause `StdSim` to not save the output sent to it.
See documentation for `CommandResult` in `pyscript_bridge.py` for reasons pausing the storage can be useful.
- Added ability to disable/enable individual commands and entire categories of commands. When a command
is disabled, it will not show up in the help menu or tab complete. If a user tries to run the command
or call help on it, a command-specific message supplied by the developer will be printed. The following
commands were added to support this feature.
- `enable_command()`
- `enable_category()`
- `disable_command()`
- `disable_category()`
- Potentially breaking changes
- Made `cmd2_app` a positional and required argument of `AutoCompleter` since certain functionality now
requires that it can't be `None`.
- `AutoCompleter` no longer assumes `CompletionItem` results are sorted. Therefore you should follow the
`cmd2` convention of setting `self.matches_sorted` to True before returning the results if you have already
sorted the `CompletionItem` list. Otherwise it will be sorted using `self.matches_sort_key`.
- Removed support for bash completion since this feature had slow performance. Also it relied on
`AutoCompleter` which has since developed a dependency on `cmd2` methods.
- Removed ability to call commands in `pyscript` as if they were functions (e.g. `app.help()`) in favor
of only supporting one `pyscript` interface. This simplifies future maintenance.
- No longer supporting C-style comments. Hash () is the only valid comment marker.
- No longer supporting comments embedded in a command. Only command line input where the first
non-whitespace character is a will be treated as a comment. This means any character appearing
later in the command will be treated as a literal. The same applies to a in the middle of a multiline
command, even if it is the first character on a line.
_ \ this is a comment
_ this is not a comment

- Bug Fixes
- Fixed unit test that hangs on Windows

- Bug Fixes
- Fixed bug where the `set` command was not tab completing from the current `settable` dictionary.
- Enhancements
- Changed edit command to use do_shell() instead of calling os.system()

- Bug Fixes
- Fixed issue with echoing strings in StdSim. Because they were being sent to a binary buffer, line buffering
was being ignored.
- Enhancements
- Made quit() and exit() functions available to scripts run with pyscript. This allows those scripts to exit
back to the console's prompt instead of exiting the whole application.