diff options
Diffstat (limited to 'cmd2/rl_utils.py')
| -rw-r--r-- | cmd2/rl_utils.py | 60 |
1 files changed, 47 insertions, 13 deletions
diff --git a/cmd2/rl_utils.py b/cmd2/rl_utils.py index a79f1519..b2dc7649 100644 --- a/cmd2/rl_utils.py +++ b/cmd2/rl_utils.py @@ -1,11 +1,15 @@ # coding=utf-8 """ -Imports the proper readline for the platform and provides utility functions for it +Imports the proper Readline for the platform and provides utility functions for it """ import sys from enum import ( Enum, ) +from typing import ( + Union, + cast, +) # Prefer statically linked gnureadline if available (for macOS compatibility due to issues with libedit) try: @@ -29,13 +33,13 @@ class RlType(Enum): NONE = 3 -# Check what implementation of readline we are using +# Check what implementation of Readline we are using rl_type = RlType.NONE # Tells if the terminal we are running in supports vt100 control characters vt100_support = False -# Explanation for why readline wasn't loaded +# Explanation for why Readline wasn't loaded _rl_warn_reason = '' # The order of this check matters since importing pyreadline/pyreadline3 will also show readline in the modules list @@ -188,23 +192,43 @@ def rl_get_point() -> int: # pragma: no cover return 0 -# noinspection PyProtectedMember, PyUnresolvedReferences +# noinspection PyUnresolvedReferences +def rl_get_prompt() -> str: # pragma: no cover + """Gets Readline's current prompt""" + if rl_type == RlType.GNU: + encoded_prompt = ctypes.c_char_p.in_dll(readline_lib, "rl_prompt").value + prompt = cast(bytes, encoded_prompt).decode(encoding='utf-8') + + elif rl_type == RlType.PYREADLINE: + prompt_data: Union[str, bytes] = readline.rl.prompt + if isinstance(prompt_data, bytes): + prompt = prompt_data.decode(encoding='utf-8') + else: + prompt = prompt_data + + else: + prompt = '' + + return rl_unescape_prompt(prompt) + + +# noinspection PyUnresolvedReferences def rl_set_prompt(prompt: str) -> None: # pragma: no cover """ - Sets readline's prompt + Sets Readline's prompt :param prompt: the new prompt value """ - safe_prompt = rl_make_safe_prompt(prompt) + escaped_prompt = rl_escape_prompt(prompt) if rl_type == RlType.GNU: - encoded_prompt = bytes(safe_prompt, encoding='utf-8') + encoded_prompt = bytes(escaped_prompt, encoding='utf-8') readline_lib.rl_set_prompt(encoded_prompt) elif rl_type == RlType.PYREADLINE: - readline.rl._set_prompt(safe_prompt) + readline.rl.prompt = escaped_prompt -def rl_make_safe_prompt(prompt: str) -> str: # pragma: no cover +def rl_escape_prompt(prompt: str) -> str: """Overcome bug in GNU Readline in relation to calculation of prompt length in presence of ANSI escape codes :param prompt: original prompt @@ -212,20 +236,20 @@ def rl_make_safe_prompt(prompt: str) -> str: # pragma: no cover """ if rl_type == RlType.GNU: # start code to tell GNU Readline about beginning of invisible characters - start = "\x01" + escape_start = "\x01" # end code to tell GNU Readline about end of invisible characters - end = "\x02" + escape_end = "\x02" escaped = False result = "" for c in prompt: if c == "\x1b" and not escaped: - result += start + c + result += escape_start + c escaped = True elif c.isalpha() and escaped: - result += c + end + result += c + escape_end escaped = False else: result += c @@ -234,3 +258,13 @@ def rl_make_safe_prompt(prompt: str) -> str: # pragma: no cover else: return prompt + + +def rl_unescape_prompt(prompt: str) -> str: + """Remove escape characters from a Readline prompt""" + if rl_type == RlType.GNU: + escape_start = "\x01" + escape_end = "\x02" + prompt = prompt.replace(escape_start, "").replace(escape_end, "") + + return prompt |