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