1"""Filename globbing utility."""
2
3import contextlib
4import os
5import re
6import fnmatch
7import itertools
8import stat
9import sys
10
11__all__ = ["glob", "iglob", "escape"]
12
13def glob(pathname, *, root_dir=None, dir_fd=None, recursive=False,
14        include_hidden=False):
15    """Return a list of paths matching a pathname pattern.
16
17    The pattern may contain simple shell-style wildcards a la
18    fnmatch. Unlike fnmatch, filenames starting with a
19    dot are special cases that are not matched by '*' and '?'
20    patterns by default.
21
22    If `include_hidden` is true, the patterns '*', '?', '**'  will match hidden
23    directories.
24
25    If `recursive` is true, the pattern '**' will match any files and
26    zero or more directories and subdirectories.
27    """
28    return list(iglob(pathname, root_dir=root_dir, dir_fd=dir_fd, recursive=recursive,
29                      include_hidden=include_hidden))
30
31def iglob(pathname, *, root_dir=None, dir_fd=None, recursive=False,
32          include_hidden=False):
33    """Return an iterator which yields the paths matching a pathname pattern.
34
35    The pattern may contain simple shell-style wildcards a la
36    fnmatch. However, unlike fnmatch, filenames starting with a
37    dot are special cases that are not matched by '*' and '?'
38    patterns.
39
40    If recursive is true, the pattern '**' will match any files and
41    zero or more directories and subdirectories.
42    """
43    sys.audit("glob.glob", pathname, recursive)
44    sys.audit("glob.glob/2", pathname, recursive, root_dir, dir_fd)
45    if root_dir is not None:
46        root_dir = os.fspath(root_dir)
47    else:
48        root_dir = pathname[:0]
49    it = _iglob(pathname, root_dir, dir_fd, recursive, False,
50                include_hidden=include_hidden)
51    if not pathname or recursive and _isrecursive(pathname[:2]):
52        try:
53            s = next(it)  # skip empty string
54            if s:
55                it = itertools.chain((s,), it)
56        except StopIteration:
57            pass
58    return it
59
60def _iglob(pathname, root_dir, dir_fd, recursive, dironly,
61           include_hidden=False):
62    dirname, basename = os.path.split(pathname)
63    if not has_magic(pathname):
64        assert not dironly
65        if basename:
66            if _lexists(_join(root_dir, pathname), dir_fd):
67                yield pathname
68        else:
69            # Patterns ending with a slash should match only directories
70            if _isdir(_join(root_dir, dirname), dir_fd):
71                yield pathname
72        return
73    if not dirname:
74        if recursive and _isrecursive(basename):
75            yield from _glob2(root_dir, basename, dir_fd, dironly,
76                             include_hidden=include_hidden)
77        else:
78            yield from _glob1(root_dir, basename, dir_fd, dironly,
79                              include_hidden=include_hidden)
80        return
81    # `os.path.split()` returns the argument itself as a dirname if it is a
82    # drive or UNC path.  Prevent an infinite recursion if a drive or UNC path
83    # contains magic characters (i.e. r'\\?\C:').
84    if dirname != pathname and has_magic(dirname):
85        dirs = _iglob(dirname, root_dir, dir_fd, recursive, True,
86                      include_hidden=include_hidden)
87    else:
88        dirs = [dirname]
89    if has_magic(basename):
90        if recursive and _isrecursive(basename):
91            glob_in_dir = _glob2
92        else:
93            glob_in_dir = _glob1
94    else:
95        glob_in_dir = _glob0
96    for dirname in dirs:
97        for name in glob_in_dir(_join(root_dir, dirname), basename, dir_fd, dironly,
98                               include_hidden=include_hidden):
99            yield os.path.join(dirname, name)
100
101# These 2 helper functions non-recursively glob inside a literal directory.
102# They return a list of basenames.  _glob1 accepts a pattern while _glob0
103# takes a literal basename (so it only has to check for its existence).
104
105def _glob1(dirname, pattern, dir_fd, dironly, include_hidden=False):
106    names = _listdir(dirname, dir_fd, dironly)
107    if include_hidden or not _ishidden(pattern):
108        names = (x for x in names if include_hidden or not _ishidden(x))
109    return fnmatch.filter(names, pattern)
110
111def _glob0(dirname, basename, dir_fd, dironly, include_hidden=False):
112    if basename:
113        if _lexists(_join(dirname, basename), dir_fd):
114            return [basename]
115    else:
116        # `os.path.split()` returns an empty basename for paths ending with a
117        # directory separator.  'q*x/' should match only directories.
118        if _isdir(dirname, dir_fd):
119            return [basename]
120    return []
121
122# Following functions are not public but can be used by third-party code.
123
124def glob0(dirname, pattern):
125    return _glob0(dirname, pattern, None, False)
126
127def glob1(dirname, pattern):
128    return _glob1(dirname, pattern, None, False)
129
130# This helper function recursively yields relative pathnames inside a literal
131# directory.
132
133def _glob2(dirname, pattern, dir_fd, dironly, include_hidden=False):
134    assert _isrecursive(pattern)
135    yield pattern[:0]
136    yield from _rlistdir(dirname, dir_fd, dironly,
137                         include_hidden=include_hidden)
138
139# If dironly is false, yields all file names inside a directory.
140# If dironly is true, yields only directory names.
141def _iterdir(dirname, dir_fd, dironly):
142    try:
143        fd = None
144        fsencode = None
145        if dir_fd is not None:
146            if dirname:
147                fd = arg = os.open(dirname, _dir_open_flags, dir_fd=dir_fd)
148            else:
149                arg = dir_fd
150            if isinstance(dirname, bytes):
151                fsencode = os.fsencode
152        elif dirname:
153            arg = dirname
154        elif isinstance(dirname, bytes):
155            arg = bytes(os.curdir, 'ASCII')
156        else:
157            arg = os.curdir
158        try:
159            with os.scandir(arg) as it:
160                for entry in it:
161                    try:
162                        if not dironly or entry.is_dir():
163                            if fsencode is not None:
164                                yield fsencode(entry.name)
165                            else:
166                                yield entry.name
167                    except OSError:
168                        pass
169        finally:
170            if fd is not None:
171                os.close(fd)
172    except OSError:
173        return
174
175def _listdir(dirname, dir_fd, dironly):
176    with contextlib.closing(_iterdir(dirname, dir_fd, dironly)) as it:
177        return list(it)
178
179# Recursively yields relative pathnames inside a literal directory.
180def _rlistdir(dirname, dir_fd, dironly, include_hidden=False):
181    names = _listdir(dirname, dir_fd, dironly)
182    for x in names:
183        if include_hidden or not _ishidden(x):
184            yield x
185            path = _join(dirname, x) if dirname else x
186            for y in _rlistdir(path, dir_fd, dironly,
187                               include_hidden=include_hidden):
188                yield _join(x, y)
189
190
191def _lexists(pathname, dir_fd):
192    # Same as os.path.lexists(), but with dir_fd
193    if dir_fd is None:
194        return os.path.lexists(pathname)
195    try:
196        os.lstat(pathname, dir_fd=dir_fd)
197    except (OSError, ValueError):
198        return False
199    else:
200        return True
201
202def _isdir(pathname, dir_fd):
203    # Same as os.path.isdir(), but with dir_fd
204    if dir_fd is None:
205        return os.path.isdir(pathname)
206    try:
207        st = os.stat(pathname, dir_fd=dir_fd)
208    except (OSError, ValueError):
209        return False
210    else:
211        return stat.S_ISDIR(st.st_mode)
212
213def _join(dirname, basename):
214    # It is common if dirname or basename is empty
215    if not dirname or not basename:
216        return dirname or basename
217    return os.path.join(dirname, basename)
218
219magic_check = re.compile('([*?[])')
220magic_check_bytes = re.compile(b'([*?[])')
221
222def has_magic(s):
223    if isinstance(s, bytes):
224        match = magic_check_bytes.search(s)
225    else:
226        match = magic_check.search(s)
227    return match is not None
228
229def _ishidden(path):
230    return path[0] in ('.', b'.'[0])
231
232def _isrecursive(pattern):
233    if isinstance(pattern, bytes):
234        return pattern == b'**'
235    else:
236        return pattern == '**'
237
238def escape(pathname):
239    """Escape all special characters.
240    """
241    # Escaping is done by wrapping any of "*?[" between square brackets.
242    # Metacharacters do not work in the drive part and shouldn't be escaped.
243    drive, pathname = os.path.splitdrive(pathname)
244    if isinstance(pathname, bytes):
245        pathname = magic_check_bytes.sub(br'[\1]', pathname)
246    else:
247        pathname = magic_check.sub(r'[\1]', pathname)
248    return drive + pathname
249
250
251_dir_open_flags = os.O_RDONLY | getattr(os, 'O_DIRECTORY', 0)
252