Files
kitty-mirror/kitty/bash.py

137 lines
3.5 KiB
Python

#!/usr/bin/env python
# License: GPLv3 Copyright: 2022, Kovid Goyal <kovid at kovidgoyal.net>
import string
from typing import Dict, List, Tuple
ansi_c_escapes = {
'a': '\a',
'b': '\b',
'e': '\x1b',
'E': '\x1b',
'f': '\f',
'n': '\n',
'r': '\r',
't': '\t',
'v': '\v',
'\\': '\\',
"'": "'",
'"': '"',
'?': '?',
}
def ctrl_mask_char(ch: str) -> str:
try:
o = ord(ch)
except Exception:
return ch
return chr(o & 0b0011111)
def read_digit(text: str, pos: int, max_len: int, valid_digits: str, base: int) -> Tuple[str, int]:
epos = pos
while (epos - pos) <= max_len and epos < len(text) and text[epos] in valid_digits:
epos += 1
raw = text[pos:epos]
try:
return chr(int(raw, base)), epos
except Exception:
return raw, epos
def read_hex_digit(text: str, pos: int, max_len: int) -> Tuple[str, int]:
return read_digit(text, pos, max_len, string.digits + 'abcdefABCDEF', 16)
def read_octal_digit(text: str, pos: int) -> Tuple[str, int]:
return read_digit(text, pos, 3, '01234567', 8)
def decode_ansi_c_quoted_string(text: str, pos: int) -> Tuple[str, int]:
buf: List[str] = []
a = buf.append
while pos < len(text):
ch = text[pos]
pos += 1
if ch == '\\':
ec = text[pos]
pos += 1
ev = ansi_c_escapes.get(ec)
if ev is None:
if ec == 'c' and pos + 1 < len(text):
a(ctrl_mask_char(text[pos]))
pos += 1
elif ec in 'xuU' and pos + 1 < len(text):
hd, pos = read_hex_digit(text, pos, {'x': 2, 'u': 4, 'U': 8}[ec])
a(hd)
elif ec.isdigit():
hd, pos = read_octal_digit(text, pos-1)
a(hd)
else:
a(ec)
else:
a(ev)
elif ch == "'":
break
else:
a(ch)
return ''.join(buf), pos
def decode_double_quoted_string(text: str, pos: int) -> Tuple[str, int]:
escapes = r'"\$`'
buf: List[str] = []
a = buf.append
while pos < len(text):
ch = text[pos]
pos += 1
if ch == '\\':
if text[pos] in escapes:
a(text[pos])
pos += 1
continue
a(ch)
elif ch == '"':
break
else:
a(ch)
return ''.join(buf), pos
def parse_modern_bash_env(text: str) -> Dict[str, str]:
ans = {}
for line in text.splitlines():
idx = line.find('=')
if idx < 0:
break
key = line[:idx].rpartition(' ')[2]
val = line[idx+1:]
if val.startswith('"'):
val = decode_double_quoted_string(val, 1)[0]
else:
val = decode_ansi_c_quoted_string(val, 2)[0]
ans[key] = val
return ans
def parse_bash_env(text: str, bash_version: str) -> Dict[str, str]:
# See https://www.gnu.org/software/bash/manual/html_node/Double-Quotes.html
parts = bash_version.split('.')
bv = tuple(map(int, parts[:2]))
if bv >= (5, 2):
return parse_modern_bash_env(text)
ans = {}
pos = 0
while pos < len(text):
idx = text.find('="', pos)
if idx < 0:
break
i = text.rfind(' ', 0, idx)
if i < 0:
break
key = text[i+1:idx]
pos = idx + 2
ans[key], pos = decode_double_quoted_string(text, pos)
return ans