A new kitten to easily query kitty for config values

docs/changelog.rst

@@ -4,6 +4,14 @@ Changelog
 |kitty| is a feature full, cross-platform, *fast*, GPU based terminal emulator.
 To update |kitty|, :doc:`follow the instructions <binary>`.
 
+0.19.2 [future]
+-------------------
+
+- A new :doc:`kittens/query_terminal` kitten to easily query the running kitty
+  via escape codes to detect its version, and the values of
+  configuration options that enable or disable terminal features.
+
+
 0.19.1 [2020-10-06]
 -------------------
 

docs/kittens/query_terminal.rst

@@ -0,0 +1,11 @@
+Query terminal
+=================
+
+Used to query kitty from terminal programs about version, values of various
+runtime options controlling its features, etc.
+
+
+Command Line Interface
+-------------------------
+
+.. include:: ../generated/cli-kitten-query_terminal.rst

kittens/query_terminal/main.py

@@ -0,0 +1,162 @@
+#!/usr/bin/env python
+# vim:fileencoding=utf-8
+# License: GPLv3 Copyright: 2020, Kovid Goyal <kovid at kovidgoyal.net>
+
+import re
+import sys
+from binascii import unhexlify, hexlify
+from contextlib import suppress
+from typing import Dict, Iterable, List, Type
+
+from kitty.cli import parse_args
+from kitty.cli_stub import QueryTerminalCLIOptions
+from kitty.constants import appname
+from kitty.utils import TTYIO
+from kitty.terminfo import names
+
+
+class Query:
+    name: str = ''
+    ans: str = ''
+    query_name: str = ''
+    help_text: str = ''
+
+    def __init__(self) -> None:
+        self.encoded_query_name = hexlify(self.query_name.encode('utf-8')).decode('ascii')
+        self.pat = re.compile('\x1bP([01])\\+r{}(.*?)\x1b\\\\'.format(self.encoded_query_name).encode('ascii'))
+
+    def query_code(self) -> str:
+        return "\x1bP+q{}\x1b\\".format(self.encoded_query_name)
+
+    def decode_response(self, res: bytes) -> str:
+        return unhexlify(res).decode('utf-8')
+
+    def more_needed(self, buffer: bytes) -> bool:
+        m = self.pat.search(buffer)
+        if m is None:
+            return True
+        if m.group(1) == b'1':
+            q = m.group(2)
+            if q.startswith(b'='):
+                with suppress(Exception):
+                    self.ans = self.decode_response(memoryview(q)[1:])
+        return False
+
+    def output_line(self) -> str:
+        return self.ans
+
+
+all_queries: Dict[str, Type[Query]] = {}
+
+
+def query(cls: Type[Query]) -> Type[Query]:
+    all_queries[cls.name] = cls
+    return cls
+
+
+@query
+class TerminalName(Query):
+    name: str = 'name'
+    query_name: str = 'TN'
+    help_text: str = f'Terminal name ({names[0]})'
+
+
+@query
+class TerminalVersion(Query):
+    name: str = 'version'
+    query_name: str = 'kitty-query-version'
+    help_text: str = 'Terminal version, for e.g.: 0.19.2'
+
+
+@query
+class AllowHyperlinks(Query):
+    name: str = 'allow_hyperlinks'
+    query_name: str = 'kitty-query-allow_hyperlinks'
+    help_text: str = 'yes, no or ask'
+
+
+def do_queries(queries: Iterable, cli_opts: QueryTerminalCLIOptions) -> Dict[str, str]:
+    actions = tuple(all_queries[x]() for x in queries)
+    qstring = ''.join(a.query_code() for a in actions)
+    received = b''
+
+    def more_needed(data: bytes) -> bool:
+        nonlocal received
+        received += data
+        for a in actions:
+            if a.more_needed(received):
+                return True
+        return False
+
+    with TTYIO() as ttyio:
+        ttyio.send(qstring)
+        ttyio.recv(more_needed, timeout=cli_opts.wait_for)
+
+    return {a.name: a.output_line() for a in actions}
+
+
+def options_spec() -> str:
+    return '''\
+--wait-for
+type=float
+default=10
+The amount of time (in seconds) to wait for a response from the terminal, after
+querying it.
+'''
+
+
+help_text = '''\
+Query the terminal this kitten is run in for various
+capabilities. This sends escape codes to the terminal
+and based on its response prints out data about supported
+capabilities. Note that this is a blocking operation, since
+it has to wait for a response from the terminal. You can control
+the maximum wait time via the ``--wait-for`` option.
+
+The output is lines of the form::
+
+  query: data
+
+If a particular query is unsupported by the running kitty version,
+the data will be blank.
+
+Note that when calling this from another program, be very
+careful not to perform any I/O on the terminal device
+until the kitten exits.
+
+Available queries are::
+
+{}
+'''.format('  ' + '\n  '.join(
+    f'{name}: {c.help_text}' for name, c in all_queries.items()))
+usage = '[query1 query2 ...]'
+
+
+def main(args: List[str] = sys.argv) -> None:
+    cli_opts, items_ = parse_args(
+        args[1:],
+        options_spec,
+        usage,
+        help_text,
+        '{} +kitten query_terminal'.format(appname),
+        result_class=QueryTerminalCLIOptions
+    )
+    queries: List[str] = list(items_)
+    if 'all' in queries or not queries:
+        queries = sorted(all_queries)
+    else:
+        extra = frozenset(queries) - frozenset(all_queries)
+        if extra:
+            raise SystemExit(f'Unknown queries: {", ".join(extra)}')
+
+    for key, val in do_queries(queries, cli_opts).items():
+        print(key + ':', val)
+
+
+if __name__ == '__main__':
+    main()
+elif __name__ == '__doc__':
+    cd = sys.cli_docs  # type: ignore
+    cd['usage'] = usage
+    cd['options'] = options_spec
+    cd['help_text'] = help_text

kitty/cli_stub.py

@@ -13,6 +13,7 @@ class CLIOptions:
 LaunchCLIOptions = AskCLIOptions = ClipboardCLIOptions = DiffCLIOptions = CLIOptions
 HintsCLIOptions = IcatCLIOptions = PanelCLIOptions = ResizeCLIOptions = CLIOptions
 ErrorCLIOptions = UnicodeCLIOptions = RCOptions = RemoteFileCLIOptions = CLIOptions
+QueryTerminalCLIOptions = CLIOptions
 
 
 def generate_stub() -> None:
@@ -50,6 +51,9 @@ def generate_stub() -> None:
     from kittens.icat.main import options_spec
     do(options_spec(), 'IcatCLIOptions')
 
+    from kittens.query_terminal.main import options_spec
+    do(options_spec(), 'QueryTerminalCLIOptions')
+
     from kittens.panel.main import OPTIONS
     do(OPTIONS(), 'PanelCLIOptions')
 

kitty/terminfo.py

@@ -4,7 +4,10 @@
 
 import re
 from binascii import hexlify, unhexlify
-from typing import cast, Dict
+from typing import TYPE_CHECKING, Dict, Generator, Optional, cast
+
+if TYPE_CHECKING:
+    from .options_stub import Options
 
 
 def modify_key_bytes(keybytes: bytes, amt: int) -> bytes:
@@ -449,14 +452,30 @@ def key_as_bytes(name: str) -> bytes:
     return ans.encode('ascii')
 
 
-def get_capabilities(query_string: str) -> str:
+def get_capabilities(query_string: str, opts: 'Options') -> Generator[str, None, None]:
     from .fast_data_types import ERROR_PREFIX
-    ans = []
+
-    try:
+    def result(encoded_query_name: str, x: Optional[str] = None) -> str:
-        for q in query_string.split(';'):
+        if x is None:
-            name = qname = unhexlify(q).decode('utf-8')
+            return '0+r' + encoded_query_name
+        return '1+r' + encoded_query_name + '=' + hexlify(x.encode('utf-8')).decode('ascii')
+
+    for encoded_query_name in query_string.split(';'):
+        name = qname = unhexlify(encoded_query_name).decode('utf-8')
         if name in ('TN', 'name'):
-                val = names[0]
+            yield result(encoded_query_name, names[0])
+        elif name.startswith('kitty-query-'):
+            name = name[len('kitty-query-'):]
+            if name == 'version':
+                from .constants import str_version
+                yield result(encoded_query_name, str_version)
+            elif name == 'allow_hyperlinks':
+                yield result(encoded_query_name,
+                             'ask' if opts.allow_hyperlinks == 0b11 else ('yes' if opts.allow_hyperlinks else 'no'))
+            else:
+                from .utils import log_error
+                log_error('Unknown kitty terminfo query:', name)
+                yield result(encoded_query_name)
         else:
             try:
                 val = queryable_capabilities[name]
@@ -467,10 +486,8 @@ def get_capabilities(query_string: str) -> str:
                 except Exception:
                     from .utils import log_error
                     log_error(ERROR_PREFIX, 'Unknown terminfo property:', name)
-                        raise
+                    yield result(encoded_query_name)
+                    continue
             if qname in string_capabilities and '%' not in val:
                 val = key_as_bytes(qname).decode('ascii')
-            ans.append(q + '=' + hexlify(str(val).encode('utf-8')).decode('ascii'))
+            yield result(encoded_query_name, val)
-        return '1+r' + ';'.join(ans)
-    except Exception:
-        return '0+r' + query_string

kitty/window.py

@@ -704,7 +704,8 @@ class Window:
             self.refresh()
 
     def request_capabilities(self, q: str) -> None:
-        self.screen.send_escape_code_to_child(DCS, get_capabilities(q))
+        for result in get_capabilities(q, self.opts):
+            self.screen.send_escape_code_to_child(DCS, result)
 
     def handle_remote_cmd(self, cmd: str) -> None:
         get_boss().handle_remote_cmd(cmd, self)

kitty_tests/__init__.py

@@ -31,7 +31,7 @@ class Callbacks:
 
     def request_capabilities(self, q):
         from kitty.terminfo import get_capabilities
-        c = get_capabilities(q)
+        for c in get_capabilities(q, None):
             self.write(c.encode('ascii'))
 
     def use_utf8(self, on):