blob: ca4a5108fd42622e826ab3310cc0478c761925eb [file] [log] [blame]
Thomas Wouters89f507f2006-12-13 04:49:30 +00001"""
2Path operations common to more than one OS
3Do not use directly. The OS specific modules import the appropriate
4functions from this module themselves.
5"""
6import os
7import stat
8
9__all__ = ['commonprefix', 'exists', 'getatime', 'getctime', 'getmtime',
Brian Curtin490b32a2012-12-26 07:03:03 -060010 'getsize', 'isdir', 'isfile', 'samefile', 'sameopenfile',
11 'samestat']
Thomas Wouters89f507f2006-12-13 04:49:30 +000012
13
14# Does a path exist?
15# This is false for dangling symbolic links on systems that support them.
16def exists(path):
17 """Test whether a path exists. Returns False for broken symbolic links"""
18 try:
Georg Brandl89fad142010-03-14 10:23:39 +000019 os.stat(path)
Andrew Svetlovad28c7f2012-12-18 22:02:39 +020020 except OSError:
Thomas Wouters89f507f2006-12-13 04:49:30 +000021 return False
22 return True
23
24
25# This follows symbolic links, so both islink() and isdir() can be true
Ezio Melotti30b9d5d2013-08-17 15:50:46 +030026# for the same path on systems that support symlinks
Thomas Wouters89f507f2006-12-13 04:49:30 +000027def isfile(path):
28 """Test whether a path is a regular file"""
29 try:
30 st = os.stat(path)
Andrew Svetlovad28c7f2012-12-18 22:02:39 +020031 except OSError:
Thomas Wouters89f507f2006-12-13 04:49:30 +000032 return False
33 return stat.S_ISREG(st.st_mode)
34
35
36# Is a path a directory?
37# This follows symbolic links, so both islink() and isdir()
38# can be true for the same path on systems that support symlinks
39def isdir(s):
40 """Return true if the pathname refers to an existing directory."""
41 try:
42 st = os.stat(s)
Andrew Svetlovad28c7f2012-12-18 22:02:39 +020043 except OSError:
Thomas Wouters89f507f2006-12-13 04:49:30 +000044 return False
45 return stat.S_ISDIR(st.st_mode)
46
47
48def getsize(filename):
49 """Return the size of a file, reported by os.stat()."""
50 return os.stat(filename).st_size
51
52
53def getmtime(filename):
54 """Return the last modification time of a file, reported by os.stat()."""
55 return os.stat(filename).st_mtime
56
57
58def getatime(filename):
59 """Return the last access time of a file, reported by os.stat()."""
60 return os.stat(filename).st_atime
61
62
63def getctime(filename):
64 """Return the metadata change time of a file, reported by os.stat()."""
65 return os.stat(filename).st_ctime
66
67
68# Return the longest prefix of all list elements.
69def commonprefix(m):
70 "Given a list of pathnames, returns the longest common leading component"
71 if not m: return ''
72 s1 = min(m)
73 s2 = max(m)
Guido van Rossum360e4b82007-05-14 22:51:27 +000074 for i, c in enumerate(s1):
75 if c != s2[i]:
Thomas Wouters89f507f2006-12-13 04:49:30 +000076 return s1[:i]
Guido van Rossum360e4b82007-05-14 22:51:27 +000077 return s1
Guido van Rossumd8faa362007-04-27 19:54:29 +000078
Brian Curtin490b32a2012-12-26 07:03:03 -060079# Are two stat buffers (obtained from stat, fstat or lstat)
80# describing the same file?
81def samestat(s1, s2):
82 """Test whether two stat buffers reference the same file"""
83 return (s1.st_ino == s2.st_ino and
84 s1.st_dev == s2.st_dev)
85
86
87# Are two filenames really pointing to the same file?
88def samefile(f1, f2):
89 """Test whether two pathnames reference the same actual file"""
90 s1 = os.stat(f1)
91 s2 = os.stat(f2)
92 return samestat(s1, s2)
93
94
95# Are two open files really referencing the same file?
96# (Not necessarily the same file descriptor!)
97def sameopenfile(fp1, fp2):
98 """Test whether two open file objects reference the same file"""
99 s1 = os.fstat(fp1)
100 s2 = os.fstat(fp2)
101 return samestat(s1, s2)
102
103
Guido van Rossumd8faa362007-04-27 19:54:29 +0000104# Split a path in root and extension.
105# The extension is everything starting at the last dot in the last
106# pathname component; the root is everything before that.
107# It is always true that root + ext == p.
108
109# Generic implementation of splitext, to be parametrized with
110# the separators
111def _splitext(p, sep, altsep, extsep):
112 """Split the extension from a pathname.
113
114 Extension is everything from the last dot to the end, ignoring
115 leading dots. Returns "(root, ext)"; ext may be empty."""
Guido van Rossumf0af3e32008-10-02 18:55:37 +0000116 # NOTE: This code must work for text and bytes strings.
Guido van Rossumd8faa362007-04-27 19:54:29 +0000117
118 sepIndex = p.rfind(sep)
119 if altsep:
120 altsepIndex = p.rfind(altsep)
121 sepIndex = max(sepIndex, altsepIndex)
122
123 dotIndex = p.rfind(extsep)
124 if dotIndex > sepIndex:
125 # skip all leading dots
126 filenameIndex = sepIndex + 1
127 while filenameIndex < dotIndex:
Guido van Rossumf0af3e32008-10-02 18:55:37 +0000128 if p[filenameIndex:filenameIndex+1] != extsep:
Guido van Rossumd8faa362007-04-27 19:54:29 +0000129 return p[:dotIndex], p[dotIndex:]
130 filenameIndex += 1
131
Guido van Rossumf0af3e32008-10-02 18:55:37 +0000132 return p, p[:0]