Mercurial > hg
view mercurial/posix.py @ 50896:b2b8c25f9462
hgwebmod: use sysstr to check for attribute presence
We do not need bytes here.
author | Pierre-Yves David <pierre-yves.david@octobus.net> |
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date | Wed, 30 Aug 2023 13:28:09 +0200 |
parents | 07792fd1837f |
children | 18c8c18993f0 |
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line source
# posix.py - Posix utility function implementations for Mercurial # # Copyright 2005-2009 Olivia Mackall <olivia@selenic.com> and others # # This software may be used and distributed according to the terms of the # GNU General Public License version 2 or any later version. import errno import fcntl import getpass import grp import os import pwd import re import select import stat import sys import tempfile import typing import unicodedata from typing import ( Any, AnyStr, Iterable, Iterator, List, Match, NoReturn, Optional, Sequence, Tuple, Union, ) from .i18n import _ from .pycompat import ( getattr, open, ) from . import ( encoding, error, policy, pycompat, ) osutil = policy.importmod('osutil') normpath = os.path.normpath samestat = os.path.samestat abspath = os.path.abspath # re-exports try: oslink = os.link except AttributeError: # Some platforms build Python without os.link on systems that are # vaguely unix-like but don't have hardlink support. For those # poor souls, just say we tried and that it failed so we fall back # to copies. def oslink(src: bytes, dst: bytes) -> NoReturn: raise OSError( errno.EINVAL, b'hardlinks not supported: %s to %s' % (src, dst) ) readlink = os.readlink unlink = os.unlink rename = os.rename removedirs = os.removedirs if typing.TYPE_CHECKING: # Replace the various overloads that come along with aliasing stdlib methods # with the narrow definition that we care about in the type checking phase # only. This ensures that both Windows and POSIX see only the definition # that is actually available. # # Note that if we check pycompat.TYPE_CHECKING here, it is always False, and # the methods aren't replaced. def normpath(path: bytes) -> bytes: raise NotImplementedError def abspath(path: AnyStr) -> AnyStr: raise NotImplementedError def oslink(src: bytes, dst: bytes) -> None: raise NotImplementedError def readlink(path: bytes) -> bytes: raise NotImplementedError def unlink(path: bytes) -> None: raise NotImplementedError def rename(src: bytes, dst: bytes) -> None: raise NotImplementedError def removedirs(name: bytes) -> None: raise NotImplementedError expandglobs: bool = False umask: int = os.umask(0) os.umask(umask) posixfile = open def split(p: bytes) -> Tuple[bytes, bytes]: """Same as posixpath.split, but faster >>> import posixpath >>> for f in [b'/absolute/path/to/file', ... b'relative/path/to/file', ... b'file_alone', ... b'path/to/directory/', ... b'/multiple/path//separators', ... b'/file_at_root', ... b'///multiple_leading_separators_at_root', ... b'']: ... assert split(f) == posixpath.split(f), f """ ht = p.rsplit(b'/', 1) if len(ht) == 1: return b'', p nh = ht[0].rstrip(b'/') if nh: return nh, ht[1] return ht[0] + b'/', ht[1] def openhardlinks() -> bool: '''return true if it is safe to hold open file handles to hardlinks''' return True def nlinks(name: bytes) -> int: '''return number of hardlinks for the given file''' return os.lstat(name).st_nlink def parsepatchoutput(output_line: bytes) -> bytes: """parses the output produced by patch and returns the filename""" pf = output_line[14:] if pycompat.sysplatform == b'OpenVMS': if pf[0] == b'`': pf = pf[1:-1] # Remove the quotes else: if pf.startswith(b"'") and pf.endswith(b"'") and b" " in pf: pf = pf[1:-1] # Remove the quotes return pf def sshargs( sshcmd: bytes, host: bytes, user: Optional[bytes], port: Optional[bytes] ) -> bytes: '''Build argument list for ssh''' args = user and (b"%s@%s" % (user, host)) or host if b'-' in args[:1]: raise error.Abort( _(b'illegal ssh hostname or username starting with -: %s') % args ) args = shellquote(args) if port: args = b'-p %s %s' % (shellquote(port), args) return args def isexec(f: bytes) -> bool: """check whether a file is executable""" return os.lstat(f).st_mode & 0o100 != 0 def setflags(f: bytes, l: bool, x: bool) -> None: st = os.lstat(f) s = st.st_mode if l: if not stat.S_ISLNK(s): # switch file to link with open(f, b'rb') as fp: data = fp.read() unlink(f) try: os.symlink(data, f) except OSError: # failed to make a link, rewrite file with open(f, b"wb") as fp: fp.write(data) # no chmod needed at this point return if stat.S_ISLNK(s): # switch link to file data = os.readlink(f) unlink(f) with open(f, b"wb") as fp: fp.write(data) s = 0o666 & ~umask # avoid restatting for chmod sx = s & 0o100 if st.st_nlink > 1 and bool(x) != bool(sx): # the file is a hardlink, break it with open(f, b"rb") as fp: data = fp.read() unlink(f) with open(f, b"wb") as fp: fp.write(data) if x and not sx: # Turn on +x for every +r bit when making a file executable # and obey umask. os.chmod(f, s | (s & 0o444) >> 2 & ~umask) elif not x and sx: # Turn off all +x bits os.chmod(f, s & 0o666) def copymode( src: bytes, dst: bytes, mode: Optional[bytes] = None, enforcewritable: bool = False, ) -> None: """Copy the file mode from the file at path src to dst. If src doesn't exist, we're using mode instead. If mode is None, we're using umask.""" try: st_mode = os.lstat(src).st_mode & 0o777 except FileNotFoundError: st_mode = mode if st_mode is None: st_mode = ~umask st_mode &= 0o666 new_mode = st_mode if enforcewritable: new_mode |= stat.S_IWUSR os.chmod(dst, new_mode) def checkexec(path: bytes) -> bool: """ Check whether the given path is on a filesystem with UNIX-like exec flags Requires a directory (like /foo/.hg) """ # VFAT on some Linux versions can flip mode but it doesn't persist # a FS remount. Frequently we can detect it if files are created # with exec bit on. try: EXECFLAGS = stat.S_IXUSR | stat.S_IXGRP | stat.S_IXOTH basedir = os.path.join(path, b'.hg') cachedir = os.path.join(basedir, b'wcache') storedir = os.path.join(basedir, b'store') if not os.path.exists(cachedir): try: # we want to create the 'cache' directory, not the '.hg' one. # Automatically creating '.hg' directory could silently spawn # invalid Mercurial repositories. That seems like a bad idea. os.mkdir(cachedir) if os.path.exists(storedir): copymode(storedir, cachedir) else: copymode(basedir, cachedir) except (IOError, OSError): # we other fallback logic triggers pass if os.path.isdir(cachedir): checkisexec = os.path.join(cachedir, b'checkisexec') checknoexec = os.path.join(cachedir, b'checknoexec') try: m = os.stat(checkisexec).st_mode except FileNotFoundError: # checkisexec does not exist - fall through ... pass else: # checkisexec exists, check if it actually is exec if m & EXECFLAGS != 0: # ensure checknoexec exists, check it isn't exec try: m = os.stat(checknoexec).st_mode except FileNotFoundError: open(checknoexec, b'w').close() # might fail m = os.stat(checknoexec).st_mode if m & EXECFLAGS == 0: # check-exec is exec and check-no-exec is not exec return True # checknoexec exists but is exec - delete it unlink(checknoexec) # checkisexec exists but is not exec - delete it unlink(checkisexec) # check using one file, leave it as checkisexec checkdir = cachedir else: # check directly in path and don't leave checkisexec behind checkdir = path checkisexec = None fh, fn = pycompat.mkstemp(dir=checkdir, prefix=b'hg-checkexec-') try: os.close(fh) m = os.stat(fn).st_mode if m & EXECFLAGS == 0: os.chmod(fn, m & 0o777 | EXECFLAGS) if os.stat(fn).st_mode & EXECFLAGS != 0: if checkisexec is not None: os.rename(fn, checkisexec) fn = None return True finally: if fn is not None: unlink(fn) except (IOError, OSError): # we don't care, the user probably won't be able to commit anyway return False def checklink(path: bytes) -> bool: """check whether the given path is on a symlink-capable filesystem""" # mktemp is not racy because symlink creation will fail if the # file already exists while True: cachedir = os.path.join(path, b'.hg', b'wcache') checklink = os.path.join(cachedir, b'checklink') # try fast path, read only if os.path.islink(checklink): return True if os.path.isdir(cachedir): checkdir = cachedir else: checkdir = path cachedir = None name = tempfile.mktemp( dir=pycompat.fsdecode(checkdir), prefix=r'checklink-' ) name = pycompat.fsencode(name) try: fd = None if cachedir is None: fd = pycompat.namedtempfile( dir=checkdir, prefix=b'hg-checklink-' ) target = os.path.basename(fd.name) else: # create a fixed file to link to; doesn't matter if it # already exists. target = b'checklink-target' try: fullpath = os.path.join(cachedir, target) open(fullpath, b'w').close() except PermissionError: # If we can't write to cachedir, just pretend # that the fs is readonly and by association # that the fs won't support symlinks. This # seems like the least dangerous way to avoid # data loss. return False try: os.symlink(target, name) if cachedir is None: unlink(name) else: try: os.rename(name, checklink) except OSError: unlink(name) return True except FileExistsError: # link creation might race, try again continue finally: if fd is not None: fd.close() except AttributeError: return False except OSError as inst: # sshfs might report failure while successfully creating the link if inst.errno == errno.EIO and os.path.exists(name): unlink(name) return False def checkosfilename(path: bytes) -> Optional[bytes]: """Check that the base-relative path is a valid filename on this platform. Returns None if the path is ok, or a UI string describing the problem.""" return None # on posix platforms, every path is ok def getfsmountpoint(dirpath: bytes) -> Optional[bytes]: """Get the filesystem mount point from a directory (best-effort) Returns None if we are unsure. Raises OSError on ENOENT, EPERM, etc. """ return getattr(osutil, 'getfsmountpoint', lambda x: None)(dirpath) def getfstype(dirpath: bytes) -> Optional[bytes]: """Get the filesystem type name from a directory (best-effort) Returns None if we are unsure. Raises OSError on ENOENT, EPERM, etc. """ return getattr(osutil, 'getfstype', lambda x: None)(dirpath) def get_password() -> bytes: return encoding.strtolocal(getpass.getpass('')) def setbinary(fd) -> None: pass def pconvert(path: bytes) -> bytes: return path def localpath(path: bytes) -> bytes: return path def samefile(fpath1: bytes, fpath2: bytes) -> bool: """Returns whether path1 and path2 refer to the same file. This is only guaranteed to work for files, not directories.""" return os.path.samefile(fpath1, fpath2) def samedevice(fpath1: bytes, fpath2: bytes) -> bool: """Returns whether fpath1 and fpath2 are on the same device. This is only guaranteed to work for files, not directories.""" st1 = os.lstat(fpath1) st2 = os.lstat(fpath2) return st1.st_dev == st2.st_dev # os.path.normcase is a no-op, which doesn't help us on non-native filesystems def normcase(path: bytes) -> bytes: return path.lower() # what normcase does to ASCII strings normcasespec: int = encoding.normcasespecs.lower # fallback normcase function for non-ASCII strings normcasefallback = normcase if pycompat.isdarwin: def normcase(path: bytes) -> bytes: """ Normalize a filename for OS X-compatible comparison: - escape-encode invalid characters - decompose to NFD - lowercase - omit ignored characters [200c-200f, 202a-202e, 206a-206f,feff] >>> normcase(b'UPPER') 'upper' >>> normcase(b'Caf\\xc3\\xa9') 'cafe\\xcc\\x81' >>> normcase(b'\\xc3\\x89') 'e\\xcc\\x81' >>> normcase(b'\\xb8\\xca\\xc3\\xca\\xbe\\xc8.JPG') # issue3918 '%b8%ca%c3\\xca\\xbe%c8.jpg' """ try: return encoding.asciilower(path) # exception for non-ASCII except UnicodeDecodeError: return normcasefallback(path) normcasespec = encoding.normcasespecs.lower def normcasefallback(path: bytes) -> bytes: try: u = path.decode('utf-8') except UnicodeDecodeError: # OS X percent-encodes any bytes that aren't valid utf-8 s = b'' pos = 0 l = len(path) while pos < l: try: c = encoding.getutf8char(path, pos) pos += len(c) except ValueError: c = b'%%%02X' % ord(path[pos : pos + 1]) pos += 1 s += c u = s.decode('utf-8') # Decompose then lowercase (HFS+ technote specifies lower) enc = unicodedata.normalize('NFD', u).lower().encode('utf-8') # drop HFS+ ignored characters return encoding.hfsignoreclean(enc) if pycompat.sysplatform == b'cygwin': # workaround for cygwin, in which mount point part of path is # treated as case sensitive, even though underlying NTFS is case # insensitive. # default mount points cygwinmountpoints = sorted( [ b"/usr/bin", b"/usr/lib", b"/cygdrive", ], reverse=True, ) # use upper-ing as normcase as same as NTFS workaround def normcase(path: bytes) -> bytes: pathlen = len(path) if (pathlen == 0) or (path[0] != pycompat.ossep): # treat as relative return encoding.upper(path) # to preserve case of mountpoint part for mp in cygwinmountpoints: if not path.startswith(mp): continue mplen = len(mp) if mplen == pathlen: # mount point itself return mp if path[mplen] == pycompat.ossep: return mp + encoding.upper(path[mplen:]) return encoding.upper(path) normcasespec = encoding.normcasespecs.other normcasefallback = normcase # Cygwin translates native ACLs to POSIX permissions, # but these translations are not supported by native # tools, so the exec bit tends to be set erroneously. # Therefore, disable executable bit access on Cygwin. def checkexec(path: bytes) -> bool: return False # Similarly, Cygwin's symlink emulation is likely to create # problems when Mercurial is used from both Cygwin and native # Windows, with other native tools, or on shared volumes def checklink(path: bytes) -> bool: return False _needsshellquote: Optional[Match[bytes]] = None def shellquote(s: bytes) -> bytes: if pycompat.sysplatform == b'OpenVMS': return b'"%s"' % s global _needsshellquote if _needsshellquote is None: _needsshellquote = re.compile(br'[^a-zA-Z0-9._/+-]').search if s and not _needsshellquote(s): # "s" shouldn't have to be quoted return s else: return b"'%s'" % s.replace(b"'", b"'\\''") def shellsplit(s: bytes) -> List[bytes]: """Parse a command string in POSIX shell way (best-effort)""" return pycompat.shlexsplit(s, posix=True) def testpid(pid: int) -> bool: '''return False if pid dead, True if running or not sure''' if pycompat.sysplatform == b'OpenVMS': return True try: os.kill(pid, 0) return True except OSError as inst: return inst.errno != errno.ESRCH def isowner(st: os.stat_result) -> bool: """Return True if the stat object st is from the current user.""" return st.st_uid == os.getuid() def findexe(command: bytes) -> Optional[bytes]: """Find executable for command searching like which does. If command is a basename then PATH is searched for command. PATH isn't searched if command is an absolute or relative path. If command isn't found None is returned.""" if pycompat.sysplatform == b'OpenVMS': return command def findexisting(executable: bytes) -> Optional[bytes]: b'Will return executable if existing file' if os.path.isfile(executable) and os.access(executable, os.X_OK): return executable return None if pycompat.ossep in command: return findexisting(command) if pycompat.sysplatform == b'plan9': return findexisting(os.path.join(b'/bin', command)) for path in encoding.environ.get(b'PATH', b'').split(pycompat.ospathsep): executable = findexisting(os.path.join(path, command)) if executable is not None: return executable return None def setsignalhandler() -> None: pass _wantedkinds = {stat.S_IFREG, stat.S_IFLNK} def statfiles(files: Sequence[bytes]) -> Iterator[Optional[os.stat_result]]: """Stat each file in files. Yield each stat, or None if a file does not exist or has a type we don't care about.""" lstat = os.lstat getkind = stat.S_IFMT for nf in files: try: st = lstat(nf) if getkind(st.st_mode) not in _wantedkinds: st = None except (FileNotFoundError, NotADirectoryError): st = None yield st def getuser() -> bytes: '''return name of current user''' return pycompat.fsencode(getpass.getuser()) def username(uid: Optional[int] = None) -> Optional[bytes]: """Return the name of the user with the given uid. If uid is None, return the name of the current user.""" if uid is None: uid = os.getuid() try: return pycompat.fsencode(pwd.getpwuid(uid)[0]) except KeyError: return b'%d' % uid def groupname(gid: Optional[int] = None) -> Optional[bytes]: """Return the name of the group with the given gid. If gid is None, return the name of the current group.""" if gid is None: gid = os.getgid() try: return pycompat.fsencode(grp.getgrgid(gid)[0]) except KeyError: return pycompat.bytestr(gid) def groupmembers(name: bytes) -> List[bytes]: """Return the list of members of the group with the given name, KeyError if the group does not exist. """ name = pycompat.fsdecode(name) return pycompat.rapply(pycompat.fsencode, list(grp.getgrnam(name).gr_mem)) def spawndetached(args: List[bytes]) -> int: return os.spawnvp(os.P_NOWAIT | getattr(os, 'P_DETACH', 0), args[0], args) def gethgcmd(): # TODO: convert to bytes, like on Windows? return sys.argv[:1] def makedir(path: bytes, notindexed: bool) -> None: os.mkdir(path) def lookupreg( key: bytes, name: Optional[bytes] = None, scope: Optional[Union[int, Iterable[int]]] = None, ) -> Optional[bytes]: return None def hidewindow() -> None: """Hide current shell window. Used to hide the window opened when starting asynchronous child process under Windows, unneeded on other systems. """ pass class cachestat: def __init__(self, path: bytes) -> None: self.stat = os.stat(path) def cacheable(self) -> bool: return bool(self.stat.st_ino) __hash__ = object.__hash__ def __eq__(self, other: Any) -> bool: try: # Only dev, ino, size, mtime and atime are likely to change. Out # of these, we shouldn't compare atime but should compare the # rest. However, one of the other fields changing indicates # something fishy going on, so return False if anything but atime # changes. return ( self.stat.st_mode == other.stat.st_mode and self.stat.st_ino == other.stat.st_ino and self.stat.st_dev == other.stat.st_dev and self.stat.st_nlink == other.stat.st_nlink and self.stat.st_uid == other.stat.st_uid and self.stat.st_gid == other.stat.st_gid and self.stat.st_size == other.stat.st_size and self.stat[stat.ST_MTIME] == other.stat[stat.ST_MTIME] and self.stat[stat.ST_CTIME] == other.stat[stat.ST_CTIME] ) except AttributeError: return False def __ne__(self, other: Any) -> bool: return not self == other def statislink(st: Optional[os.stat_result]) -> bool: '''check whether a stat result is a symlink''' return stat.S_ISLNK(st.st_mode) if st else False def statisexec(st: Optional[os.stat_result]) -> bool: '''check whether a stat result is an executable file''' return (st.st_mode & 0o100 != 0) if st else False def poll(fds): """block until something happens on any file descriptor This is a generic helper that will check for any activity (read, write. exception) and return the list of touched files. In unsupported cases, it will raise a NotImplementedError""" try: res = select.select(fds, fds, fds) except ValueError: # out of range file descriptor raise NotImplementedError() return sorted(list(set(sum(res, [])))) def readpipe(pipe) -> bytes: """Read all available data from a pipe.""" # We can't fstat() a pipe because Linux will always report 0. # So, we set the pipe to non-blocking mode and read everything # that's available. flags = fcntl.fcntl(pipe, fcntl.F_GETFL) flags |= os.O_NONBLOCK oldflags = fcntl.fcntl(pipe, fcntl.F_SETFL, flags) try: chunks = [] while True: try: s = pipe.read() if not s: break chunks.append(s) except IOError: break return b''.join(chunks) finally: fcntl.fcntl(pipe, fcntl.F_SETFL, oldflags) def bindunixsocket(sock, path: bytes) -> None: """Bind the UNIX domain socket to the specified path""" # use relative path instead of full path at bind() if possible, since # AF_UNIX path has very small length limit (107 chars) on common # platforms (see sys/un.h) dirname, basename = os.path.split(path) bakwdfd = None try: if dirname: bakwdfd = os.open(b'.', os.O_DIRECTORY) os.chdir(dirname) sock.bind(basename) if bakwdfd: os.fchdir(bakwdfd) finally: if bakwdfd: os.close(bakwdfd)