source: vendor/python/2.5/Lib/distutils/file_util.py

Last change on this file was 3225, checked in by bird, 19 years ago

Python 2.5
File size: 8.1 KB
RevLine 
[3225]1"""distutils.file_util
2
3Utility functions for operating on single files.
4"""
5
6# This module should be kept compatible with Python 2.1.
7
8__revision__ = "$Id: file_util.py 37828 2004-11-10 22:23:15Z loewis $"
9
10import os
11from distutils.errors import DistutilsFileError
12from distutils import log
13
14# for generating verbose output in 'copy_file()'
15_copy_action = { None: 'copying',
16 'hard': 'hard linking',
17 'sym': 'symbolically linking' }
18
19
20def _copy_file_contents (src, dst, buffer_size=16*1024):
21 """Copy the file 'src' to 'dst'; both must be filenames. Any error
22 opening either file, reading from 'src', or writing to 'dst', raises
23 DistutilsFileError. Data is read/written in chunks of 'buffer_size'
24 bytes (default 16k). No attempt is made to handle anything apart from
25 regular files.
26 """
27 # Stolen from shutil module in the standard library, but with
28 # custom error-handling added.
29
30 fsrc = None
31 fdst = None
32 try:
33 try:
34 fsrc = open(src, 'rb')
35 except os.error, (errno, errstr):
36 raise DistutilsFileError, \
37 "could not open '%s': %s" % (src, errstr)
38
39 if os.path.exists(dst):
40 try:
41 os.unlink(dst)
42 except os.error, (errno, errstr):
43 raise DistutilsFileError, \
44 "could not delete '%s': %s" % (dst, errstr)
45
46 try:
47 fdst = open(dst, 'wb')
48 except os.error, (errno, errstr):
49 raise DistutilsFileError, \
50 "could not create '%s': %s" % (dst, errstr)
51
52 while 1:
53 try:
54 buf = fsrc.read(buffer_size)
55 except os.error, (errno, errstr):
56 raise DistutilsFileError, \
57 "could not read from '%s': %s" % (src, errstr)
58
59 if not buf:
60 break
61
62 try:
63 fdst.write(buf)
64 except os.error, (errno, errstr):
65 raise DistutilsFileError, \
66 "could not write to '%s': %s" % (dst, errstr)
67
68 finally:
69 if fdst:
70 fdst.close()
71 if fsrc:
72 fsrc.close()
73
74# _copy_file_contents()
75
76def copy_file (src, dst,
77 preserve_mode=1,
78 preserve_times=1,
79 update=0,
80 link=None,
81 verbose=0,
82 dry_run=0):
83
84 """Copy a file 'src' to 'dst'. If 'dst' is a directory, then 'src' is
85 copied there with the same name; otherwise, it must be a filename. (If
86 the file exists, it will be ruthlessly clobbered.) If 'preserve_mode'
87 is true (the default), the file's mode (type and permission bits, or
88 whatever is analogous on the current platform) is copied. If
89 'preserve_times' is true (the default), the last-modified and
90 last-access times are copied as well. If 'update' is true, 'src' will
91 only be copied if 'dst' does not exist, or if 'dst' does exist but is
92 older than 'src'.
93
94 'link' allows you to make hard links (os.link) or symbolic links
95 (os.symlink) instead of copying: set it to "hard" or "sym"; if it is
96 None (the default), files are copied. Don't set 'link' on systems that
97 don't support it: 'copy_file()' doesn't check if hard or symbolic
98 linking is available.
99
100 Under Mac OS, uses the native file copy function in macostools; on
101 other systems, uses '_copy_file_contents()' to copy file contents.
102
103 Return a tuple (dest_name, copied): 'dest_name' is the actual name of
104 the output file, and 'copied' is true if the file was copied (or would
105 have been copied, if 'dry_run' true).
106 """
107 # XXX if the destination file already exists, we clobber it if
108 # copying, but blow up if linking. Hmmm. And I don't know what
109 # macostools.copyfile() does. Should definitely be consistent, and
110 # should probably blow up if destination exists and we would be
111 # changing it (ie. it's not already a hard/soft link to src OR
112 # (not update) and (src newer than dst).
113
114 from distutils.dep_util import newer
115 from stat import ST_ATIME, ST_MTIME, ST_MODE, S_IMODE
116
117 if not os.path.isfile(src):
118 raise DistutilsFileError, \
119 "can't copy '%s': doesn't exist or not a regular file" % src
120
121 if os.path.isdir(dst):
122 dir = dst
123 dst = os.path.join(dst, os.path.basename(src))
124 else:
125 dir = os.path.dirname(dst)
126
127 if update and not newer(src, dst):
128 log.debug("not copying %s (output up-to-date)", src)
129 return dst, 0
130
131 try:
132 action = _copy_action[link]
133 except KeyError:
134 raise ValueError, \
135 "invalid value '%s' for 'link' argument" % link
136 if os.path.basename(dst) == os.path.basename(src):
137 log.info("%s %s -> %s", action, src, dir)
138 else:
139 log.info("%s %s -> %s", action, src, dst)
140
141 if dry_run:
142 return (dst, 1)
143
144 # On Mac OS, use the native file copy routine
145 if os.name == 'mac':
146 import macostools
147 try:
148 macostools.copy(src, dst, 0, preserve_times)
149 except os.error, exc:
150 raise DistutilsFileError, \
151 "could not copy '%s' to '%s': %s" % (src, dst, exc[-1])
152
153 # If linking (hard or symbolic), use the appropriate system call
154 # (Unix only, of course, but that's the caller's responsibility)
155 elif link == 'hard':
156 if not (os.path.exists(dst) and os.path.samefile(src, dst)):
157 os.link(src, dst)
158 elif link == 'sym':
159 if not (os.path.exists(dst) and os.path.samefile(src, dst)):
160 os.symlink(src, dst)
161
162 # Otherwise (non-Mac, not linking), copy the file contents and
163 # (optionally) copy the times and mode.
164 else:
165 _copy_file_contents(src, dst)
166 if preserve_mode or preserve_times:
167 st = os.stat(src)
168
169 # According to David Ascher <[email protected]>, utime() should be done
170 # before chmod() (at least under NT).
171 if preserve_times:
172 os.utime(dst, (st[ST_ATIME], st[ST_MTIME]))
173 if preserve_mode:
174 os.chmod(dst, S_IMODE(st[ST_MODE]))
175
176 return (dst, 1)
177
178# copy_file ()
179
180
181# XXX I suspect this is Unix-specific -- need porting help!
182def move_file (src, dst,
183 verbose=0,
184 dry_run=0):
185
186 """Move a file 'src' to 'dst'. If 'dst' is a directory, the file will
187 be moved into it with the same name; otherwise, 'src' is just renamed
188 to 'dst'. Return the new full name of the file.
189
190 Handles cross-device moves on Unix using 'copy_file()'. What about
191 other systems???
192 """
193 from os.path import exists, isfile, isdir, basename, dirname
194 import errno
195
196 log.info("moving %s -> %s", src, dst)
197
198 if dry_run:
199 return dst
200
201 if not isfile(src):
202 raise DistutilsFileError, \
203 "can't move '%s': not a regular file" % src
204
205 if isdir(dst):
206 dst = os.path.join(dst, basename(src))
207 elif exists(dst):
208 raise DistutilsFileError, \
209 "can't move '%s': destination '%s' already exists" % \
210 (src, dst)
211
212 if not isdir(dirname(dst)):
213 raise DistutilsFileError, \
214 "can't move '%s': destination '%s' not a valid path" % \
215 (src, dst)
216
217 copy_it = 0
218 try:
219 os.rename(src, dst)
220 except os.error, (num, msg):
221 if num == errno.EXDEV:
222 copy_it = 1
223 else:
224 raise DistutilsFileError, \
225 "couldn't move '%s' to '%s': %s" % (src, dst, msg)
226
227 if copy_it:
228 copy_file(src, dst)
229 try:
230 os.unlink(src)
231 except os.error, (num, msg):
232 try:
233 os.unlink(dst)
234 except os.error:
235 pass
236 raise DistutilsFileError, \
237 ("couldn't move '%s' to '%s' by copy/delete: " +
238 "delete '%s' failed: %s") % \
239 (src, dst, src, msg)
240
241 return dst
242
243# move_file ()
244
245
246def write_file (filename, contents):
247 """Create a file with the specified name and write 'contents' (a
248 sequence of strings without line terminators) to it.
249 """
250 f = open(filename, "w")
251 for line in contents:
252 f.write(line + "\n")
253 f.close()
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