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