"""Pure Python curses-like terminal capability queries.""" from dataclasses import dataclass, field import errno import os from pathlib import Path import re import struct # Terminfo constants MAGIC16 = 0o432 # Magic number for 16-bit terminfo format MAGIC32 = 0o1036 # Magic number for 32-bit terminfo format # Special values for absent/cancelled capabilities ABSENT_BOOLEAN = -1 ABSENT_NUMERIC = -1 CANCELLED_NUMERIC = -2 ABSENT_STRING = None CANCELLED_STRING = None # Standard string capability names from ncurses Caps file # This matches the order used by ncurses when compiling terminfo # fmt: off _STRING_NAMES: tuple[str, ...] = ( "cbt", "bel", "cr", "csr", "tbc", "clear", "el", "ed", "hpa", "cmdch", "cup", "cud1", "home", "civis", "cub1", "mrcup", "cnorm", "cuf1", "ll", "cuu1", "cvvis", "dch1", "dl1", "dsl", "hd", "smacs", "blink", "bold", "smcup", "smdc", "dim", "smir", "invis", "prot", "rev", "smso", "smul", "ech", "rmacs", "sgr0", "rmcup", "rmdc", "rmir", "rmso", "rmul", "flash", "ff", "fsl", "is1", "is2", "is3", "if", "ich1", "il1", "ip", "kbs", "ktbc", "kclr", "kctab", "kdch1", "kdl1", "kcud1", "krmir", "kel", "ked", "kf0", "kf1", "kf10", "kf2", "kf3", "kf4", "kf5", "kf6", "kf7", "kf8", "kf9", "khome", "kich1", "kil1", "kcub1", "kll", "knp", "kpp", "kcuf1", "kind", "kri", "khts", "kcuu1", "rmkx", "smkx", "lf0", "lf1", "lf10", "lf2", "lf3", "lf4", "lf5", "lf6", "lf7", "lf8", "lf9", "rmm", "smm", "nel", "pad", "dch", "dl", "cud", "ich", "indn", "il", "cub", "cuf", "rin", "cuu", "pfkey", "pfloc", "pfx", "mc0", "mc4", "mc5", "rep", "rs1", "rs2", "rs3", "rf", "rc", "vpa", "sc", "ind", "ri", "sgr", "hts", "wind", "ht", "tsl", "uc", "hu", "iprog", "ka1", "ka3", "kb2", "kc1", "kc3", "mc5p", "rmp", "acsc", "pln", "kcbt", "smxon", "rmxon", "smam", "rmam", "xonc", "xoffc", "enacs", "smln", "rmln", "kbeg", "kcan", "kclo", "kcmd", "kcpy", "kcrt", "kend", "kent", "kext", "kfnd", "khlp", "kmrk", "kmsg", "kmov", "knxt", "kopn", "kopt", "kprv", "kprt", "krdo", "kref", "krfr", "krpl", "krst", "kres", "ksav", "kspd", "kund", "kBEG", "kCAN", "kCMD", "kCPY", "kCRT", "kDC", "kDL", "kslt", "kEND", "kEOL", "kEXT", "kFND", "kHLP", "kHOM", "kIC", "kLFT", "kMSG", "kMOV", "kNXT", "kOPT", "kPRV", "kPRT", "kRDO", "kRPL", "kRIT", "kRES", "kSAV", "kSPD", "kUND", "rfi", "kf11", "kf12", "kf13", "kf14", "kf15", "kf16", "kf17", "kf18", "kf19", "kf20", "kf21", "kf22", "kf23", "kf24", "kf25", "kf26", "kf27", "kf28", "kf29", "kf30", "kf31", "kf32", "kf33", "kf34", "kf35", "kf36", "kf37", "kf38", "kf39", "kf40", "kf41", "kf42", "kf43", "kf44", "kf45", "kf46", "kf47", "kf48", "kf49", "kf50", "kf51", "kf52", "kf53", "kf54", "kf55", "kf56", "kf57", "kf58", "kf59", "kf60", "kf61", "kf62", "kf63", "el1", "mgc", "smgl", "smgr", "fln", "sclk", "dclk", "rmclk", "cwin", "wingo", "hup","dial", "qdial", "tone", "pulse", "hook", "pause", "wait", "u0", "u1", "u2", "u3", "u4", "u5", "u6", "u7", "u8", "u9", "op", "oc", "initc", "initp", "scp", "setf", "setb", "cpi", "lpi", "chr", "cvr", "defc", "swidm", "sdrfq", "sitm", "slm", "smicm", "snlq", "snrmq", "sshm", "ssubm", "ssupm", "sum", "rwidm", "ritm", "rlm", "rmicm", "rshm", "rsubm", "rsupm", "rum", "mhpa", "mcud1", "mcub1", "mcuf1", "mvpa", "mcuu1", "porder", "mcud", "mcub", "mcuf", "mcuu", "scs", "smgb", "smgbp", "smglp", "smgrp", "smgt", "smgtp", "sbim", "scsd", "rbim", "rcsd", "subcs", "supcs", "docr", "zerom", "csnm", "kmous", "minfo", "reqmp", "getm", "setaf", "setab", "pfxl", "devt", "csin", "s0ds", "s1ds", "s2ds", "s3ds", "smglr", "smgtb", "birep", "binel", "bicr", "colornm", "defbi", "endbi", "setcolor", "slines", "dispc", "smpch", "rmpch", "smsc", "rmsc", "pctrm", "scesc", "scesa", "ehhlm", "elhlm", "elohlm", "erhlm", "ethlm", "evhlm", "sgr1", "slength", "OTi2", "OTrs", "OTnl", "OTbc", "OTko", "OTma", "OTG2", "OTG3", "OTG1", "OTG4", "OTGR", "OTGL", "OTGU", "OTGD", "OTGH", "OTGV", "OTGC","meml", "memu", "box1" ) # fmt: on def _get_terminfo_dirs() -> list[Path]: """Get list of directories to search for terminfo files. Based on ncurses behavior in: - ncurses/tinfo/db_iterator.c:_nc_next_db() - ncurses/tinfo/read_entry.c:_nc_read_entry() """ dirs = [] terminfo = os.environ.get("TERMINFO") if terminfo: dirs.append(terminfo) try: home = Path.home() dirs.append(str(home / ".terminfo")) except RuntimeError: pass # Check TERMINFO_DIRS terminfo_dirs = os.environ.get("TERMINFO_DIRS", "") if terminfo_dirs: for d in terminfo_dirs.split(":"): if d: dirs.append(d) dirs.extend( [ "/etc/terminfo", "/lib/terminfo", "/usr/lib/terminfo", "/usr/share/terminfo", "/usr/share/lib/terminfo", "/usr/share/misc/terminfo", "/usr/local/lib/terminfo", "/usr/local/share/terminfo", ] ) return [Path(d) for d in dirs if Path(d).is_dir()] def _validate_terminal_name_or_raise(terminal_name: str) -> None: if not isinstance(terminal_name, str): raise TypeError("`terminal_name` must be a string") if not terminal_name: raise ValueError("`terminal_name` cannot be empty") if "\x00" in terminal_name: raise ValueError("NUL character found in `terminal_name`") t = Path(terminal_name) if len(t.parts) > 1: raise ValueError("`terminal_name` cannot contain path separators") def _read_terminfo_file(terminal_name: str) -> bytes: """Find and read terminfo file for given terminal name. Terminfo files are stored in directories using the first character of the terminal name as a subdirectory. """ _validate_terminal_name_or_raise(terminal_name) first_char = terminal_name[0].lower() filename = terminal_name for directory in _get_terminfo_dirs(): path = directory / first_char / filename if path.is_file(): return path.read_bytes() # Try with hex encoding of first char (for special chars) hex_dir = "%02x" % ord(first_char) path = directory / hex_dir / filename if path.is_file(): return path.read_bytes() raise FileNotFoundError(errno.ENOENT, os.strerror(errno.ENOENT), filename) # Hard-coded terminal capabilities for common terminals # This is a minimal subset needed by PyREPL _TERMINAL_CAPABILITIES = { # ANSI/xterm-compatible terminals "ansi": { # Bell "bel": b"\x07", # Cursor movement "cub": b"\x1b[%p1%dD", # Move cursor left N columns "cud": b"\x1b[%p1%dB", # Move cursor down N rows "cuf": b"\x1b[%p1%dC", # Move cursor right N columns "cuu": b"\x1b[%p1%dA", # Move cursor up N rows "cub1": b"\x08", # Move cursor left 1 column "cud1": b"\n", # Move cursor down 1 row "cuf1": b"\x1b[C", # Move cursor right 1 column "cuu1": b"\x1b[A", # Move cursor up 1 row "cup": b"\x1b[%i%p1%d;%p2%dH", # Move cursor to row, column "hpa": b"\x1b[%i%p1%dG", # Move cursor to column # Clear operations "clear": b"\x1b[H\x1b[2J", # Clear screen and home cursor "el": b"\x1b[K", # Clear to end of line # Insert/delete "dch": b"\x1b[%p1%dP", # Delete N characters "dch1": b"\x1b[P", # Delete 1 character "ich": b"\x1b[%p1%d@", # Insert N characters "ich1": b"", # Insert 1 character # Cursor visibility "civis": b"\x1b[?25l", # Make cursor invisible "cnorm": b"\x1b[?12l\x1b[?25h", # Make cursor normal (visible) # Scrolling "ind": b"\n", # Scroll up one line "ri": b"\x1bM", # Scroll down one line # Keypad mode "smkx": b"\x1b[?1h\x1b=", # Enable keypad mode "rmkx": b"\x1b[?1l\x1b>", # Disable keypad mode # Padding (not used in modern terminals) "pad": b"", # Function keys and special keys "kdch1": b"\x1b[3~", # Delete key "kcud1": b"\x1bOB", # Down arrow "kend": b"\x1bOF", # End key "kent": b"\x1bOM", # Enter key "khome": b"\x1bOH", # Home key "kich1": b"\x1b[2~", # Insert key "kcub1": b"\x1bOD", # Left arrow "knp": b"\x1b[6~", # Page down "kpp": b"\x1b[5~", # Page up "kcuf1": b"\x1bOC", # Right arrow "kcuu1": b"\x1bOA", # Up arrow # Function keys F1-F20 "kf1": b"\x1bOP", "kf2": b"\x1bOQ", "kf3": b"\x1bOR", "kf4": b"\x1bOS", "kf5": b"\x1b[15~", "kf6": b"\x1b[17~", "kf7": b"\x1b[18~", "kf8": b"\x1b[19~", "kf9": b"\x1b[20~", "kf10": b"\x1b[21~", "kf11": b"\x1b[23~", "kf12": b"\x1b[24~", "kf13": b"\x1b[1;2P", "kf14": b"\x1b[1;2Q", "kf15": b"\x1b[1;2R", "kf16": b"\x1b[1;2S", "kf17": b"\x1b[15;2~", "kf18": b"\x1b[17;2~", "kf19": b"\x1b[18;2~", "kf20": b"\x1b[19;2~", }, # Dumb terminal - minimal capabilities "dumb": { "bel": b"\x07", # Bell "cud1": b"\n", # Move down 1 row (newline) "ind": b"\n", # Scroll up one line (newline) }, # Linux console "linux": { # Bell "bel": b"\x07", # Cursor movement "cub": b"\x1b[%p1%dD", # Move cursor left N columns "cud": b"\x1b[%p1%dB", # Move cursor down N rows "cuf": b"\x1b[%p1%dC", # Move cursor right N columns "cuu": b"\x1b[%p1%dA", # Move cursor up N rows "cub1": b"\x08", # Move cursor left 1 column (backspace) "cud1": b"\n", # Move cursor down 1 row (newline) "cuf1": b"\x1b[C", # Move cursor right 1 column "cuu1": b"\x1b[A", # Move cursor up 1 row "cup": b"\x1b[%i%p1%d;%p2%dH", # Move cursor to row, column "hpa": b"\x1b[%i%p1%dG", # Move cursor to column # Clear operations "clear": b"\x1b[H\x1b[J", # Clear screen and home cursor (different from ansi!) "el": b"\x1b[K", # Clear to end of line # Insert/delete "dch": b"\x1b[%p1%dP", # Delete N characters "dch1": b"\x1b[P", # Delete 1 character "ich": b"\x1b[%p1%d@", # Insert N characters "ich1": b"\x1b[@", # Insert 1 character # Cursor visibility "civis": b"\x1b[?25l\x1b[?1c", # Make cursor invisible "cnorm": b"\x1b[?25h\x1b[?0c", # Make cursor normal # Scrolling "ind": b"\n", # Scroll up one line "ri": b"\x1bM", # Scroll down one line # Keypad mode "smkx": b"\x1b[?1h\x1b=", # Enable keypad mode "rmkx": b"\x1b[?1l\x1b>", # Disable keypad mode # Function keys and special keys "kdch1": b"\x1b[3~", # Delete key "kcud1": b"\x1b[B", # Down arrow "kend": b"\x1b[4~", # End key (different from ansi!) "khome": b"\x1b[1~", # Home key (different from ansi!) "kich1": b"\x1b[2~", # Insert key "kcub1": b"\x1b[D", # Left arrow "knp": b"\x1b[6~", # Page down "kpp": b"\x1b[5~", # Page up "kcuf1": b"\x1b[C", # Right arrow "kcuu1": b"\x1b[A", # Up arrow # Function keys "kf1": b"\x1b[[A", "kf2": b"\x1b[[B", "kf3": b"\x1b[[C", "kf4": b"\x1b[[D", "kf5": b"\x1b[[E", "kf6": b"\x1b[17~", "kf7": b"\x1b[18~", "kf8": b"\x1b[19~", "kf9": b"\x1b[20~", "kf10": b"\x1b[21~", "kf11": b"\x1b[23~", "kf12": b"\x1b[24~", "kf13": b"\x1b[25~", "kf14": b"\x1b[26~", "kf15": b"\x1b[28~", "kf16": b"\x1b[29~", "kf17": b"\x1b[31~", "kf18": b"\x1b[32~", "kf19": b"\x1b[33~", "kf20": b"\x1b[34~", }, } # Map common TERM values to capability sets _TERM_ALIASES = { "xterm": "ansi", "xterm-color": "ansi", "xterm-256color": "ansi", "screen": "ansi", "screen-256color": "ansi", "tmux": "ansi", "tmux-256color": "ansi", "vt100": "ansi", "vt220": "ansi", "rxvt": "ansi", "rxvt-unicode": "ansi", "rxvt-unicode-256color": "ansi", "unknown": "dumb", } @dataclass class TermInfo: terminal_name: str | bytes | None fallback: bool = True _capabilities: dict[str, bytes] = field(default_factory=dict) def __post_init__(self) -> None: """Initialize terminal capabilities for the given terminal type. Based on ncurses implementation in: - ncurses/tinfo/lib_setup.c:setupterm() and _nc_setupterm() - ncurses/tinfo/lib_setup.c:TINFO_SETUP_TERM() This version first attempts to read terminfo database files like ncurses, then, if `fallback` is True, falls back to hardcoded capabilities for common terminal types. """ # If termstr is None or empty, try to get from environment if not self.terminal_name: self.terminal_name = os.environ.get("TERM") or "ANSI" if isinstance(self.terminal_name, bytes): self.terminal_name = self.terminal_name.decode("ascii") try: self._parse_terminfo_file(self.terminal_name) except (OSError, ValueError): if not self.fallback: raise term_type = _TERM_ALIASES.get( self.terminal_name, self.terminal_name ) if term_type not in _TERMINAL_CAPABILITIES: term_type = "dumb" self._capabilities = _TERMINAL_CAPABILITIES[term_type].copy() def _parse_terminfo_file(self, terminal_name: str) -> None: """Parse a terminfo file. Populate the _capabilities dict for easy retrieval Based on ncurses implementation in: - ncurses/tinfo/read_entry.c:_nc_read_termtype() - ncurses/tinfo/read_entry.c:_nc_read_file_entry() - ncurses/tinfo/lib_ti.c:tigetstr() """ data = _read_terminfo_file(terminal_name) too_short = f"TermInfo file for {terminal_name!r} too short" offset = 12 if len(data) < offset: raise ValueError(too_short) magic, name_size, bool_count, num_count, str_count, str_size = ( struct.unpack(" len(data): raise ValueError(too_short) # Read string offsets end_offset = offset + 2 * str_count if offset > len(data): raise ValueError(too_short) string_offset_data = data[offset:end_offset] string_offsets = [ off for [off] in struct.iter_unpack(" len(data): raise ValueError(too_short) string_table = data[offset : offset + str_size] # Extract strings from string table capabilities = {} for cap, off in zip(_STRING_NAMES, string_offsets): if off < 0: # CANCELLED_STRING; we do not store those continue elif off < len(string_table): # Find null terminator end = string_table.find(0, off) if end >= 0: capabilities[cap] = string_table[off:end] # in other cases this is ABSENT_STRING; we don't store those. # Note: we don't support extended capabilities since PyREPL doesn't # need them. self._capabilities = capabilities def get(self, cap: str) -> bytes | None: """Get terminal capability string by name. """ if not isinstance(cap, str): raise TypeError(f"`cap` must be a string, not {type(cap)}") return self._capabilities.get(cap) def tparm(cap_bytes: bytes, *params: int) -> bytes: """Parameterize a terminal capability string. Based on ncurses implementation in: - ncurses/tinfo/lib_tparm.c:tparm() - ncurses/tinfo/lib_tparm.c:tparam_internal() The ncurses version implements a full stack-based interpreter for terminfo parameter strings. This pure Python version implements only the subset of parameter substitution operations needed by PyREPL: - %i (increment parameters for 1-based indexing) - %p[1-9]%d (parameter substitution) - %p[1-9]%{n}%+%d (parameter plus constant) """ if not isinstance(cap_bytes, bytes): raise TypeError(f"`cap` must be bytes, not {type(cap_bytes)}") result = cap_bytes # %i - increment parameters (1-based instead of 0-based) increment = b"%i" in result if increment: result = result.replace(b"%i", b"") # Replace %p1%d, %p2%d, etc. with actual parameter values for i in range(len(params)): pattern = b"%%p%d%%d" % (i + 1) if pattern in result: value = params[i] if increment: value += 1 result = result.replace(pattern, str(value).encode("ascii")) # Handle %p1%{1}%+%d (parameter plus constant) # Used in some cursor positioning sequences pattern_re = re.compile(rb"%p(\d)%\{(\d+)\}%\+%d") matches = list(pattern_re.finditer(result)) for match in reversed(matches): # reversed to maintain positions param_idx = int(match.group(1)) constant = int(match.group(2)) value = params[param_idx] + constant result = ( result[: match.start()] + str(value).encode("ascii") + result[match.end() :] ) return result