"""distutils.file_util Utility functions for operating on single files.""" # This module should be kept compatible with Python 2.1. __revision__ = "$Id: file_util.py 37828 2004-11-10 22:23:15Z loewis $" import osfrom distutils.errors import DistutilsFileErrorfrom distutils import log # for generating verbose output in 'copy_file()'_copy_action = { None:   'copying',                 'hard': 'hard linking',                 'sym':  'symbolically linking' }  def _copy_file_contents (src, dst, buffer_size=16*1024):    """Copy the file 'src' to 'dst'; both must be filenames.  Any error    opening either file, reading from 'src', or writing to 'dst', raises    DistutilsFileError.  Data is read/written in chunks of 'buffer_size'    bytes (default 16k).  No attempt is made to handle anything apart from    regular files.    """    # Stolen from shutil module in the standard library, but with    # custom error-handling added.     fsrc = None    fdst = None    try:        try:            fsrc = open(src, 'rb')        except os.error, (errno, errstr):            raise DistutilsFileError, \                  "could not open '%s': %s" % (src, errstr)         if os.path.exists(dst):            try:                os.unlink(dst)            except os.error, (errno, errstr):                raise DistutilsFileError, \                      "could not delete '%s': %s" % (dst, errstr)         try:            fdst = open(dst, 'wb')        except os.error, (errno, errstr):            raise DistutilsFileError, \                  "could not create '%s': %s" % (dst, errstr)         while 1:            try:                buf = fsrc.read(buffer_size)            except os.error, (errno, errstr):                raise DistutilsFileError, \                      "could not read from '%s': %s" % (src, errstr)             if not buf:                break             try:                fdst.write(buf)            except os.error, (errno, errstr):                raise DistutilsFileError, \                      "could not write to '%s': %s" % (dst, errstr)     finally:        if fdst:            fdst.close()        if fsrc:            fsrc.close() # _copy_file_contents() def copy_file (src, dst,               preserve_mode=1,               preserve_times=1,               update=0,               link=None,               verbose=0,               dry_run=0):     """Copy a file 'src' to 'dst'.  If 'dst' is a directory, then 'src' is    copied there with the same name; otherwise, it must be a filename.  (If    the file exists, it will be ruthlessly clobbered.)  If 'preserve_mode'    is true (the default), the file's mode (type and permission bits, or    whatever is analogous on the current platform) is copied.  If    'preserve_times' is true (the default), the last-modified and    last-access times are copied as well.  If 'update' is true, 'src' will    only be copied if 'dst' does not exist, or if 'dst' does exist but is    older than 'src'.     'link' allows you to make hard links (os.link) or symbolic links    (os.symlink) instead of copying: set it to "hard" or "sym"; if it is    None (the default), files are copied.  Don't set 'link' on systems that    don't support it: 'copy_file()' doesn't check if hard or symbolic    linking is available.     Under Mac OS, uses the native file copy function in macostools; on    other systems, uses '_copy_file_contents()' to copy file contents.     Return a tuple (dest_name, copied): 'dest_name' is the actual name of    the output file, and 'copied' is true if the file was copied (or would    have been copied, if 'dry_run' true).    """    # XXX if the destination file already exists, we clobber it if    # copying, but blow up if linking.  Hmmm.  And I don't know what    # macostools.copyfile() does.  Should definitely be consistent, and    # should probably blow up if destination exists and we would be    # changing it (ie. it's not already a hard/soft link to src OR    # (not update) and (src newer than dst).     from distutils.dep_util import newer    from stat import ST_ATIME, ST_MTIME, ST_MODE, S_IMODE     if not os.path.isfile(src):        raise DistutilsFileError, \              "can't copy '%s': doesn't exist or not a regular file" % src     if os.path.isdir(dst):        dir = dst        dst = os.path.join(dst, os.path.basename(src))    else:        dir = os.path.dirname(dst)     if update and not newer(src, dst):        log.debug("not copying %s (output up-to-date)", src)        return dst, 0     try:        action = _copy_action[link]    except KeyError:        raise ValueError, \              "invalid value '%s' for 'link' argument" % link    if os.path.basename(dst) == os.path.basename(src):        log.info("%s %s -> %s", action, src, dir)    else:        log.info("%s %s -> %s", action, src, dst)     if dry_run:        return (dst, 1)     # On Mac OS, use the native file copy routine    if os.name == 'mac':        import macostools        try:            macostools.copy(src, dst, 0, preserve_times)        except os.error, exc:            raise DistutilsFileError, \                  "could not copy '%s' to '%s': %s" % (src, dst, exc[-1])     # If linking (hard or symbolic), use the appropriate system call    # (Unix only, of course, but that's the caller's responsibility)    elif link == 'hard':        if not (os.path.exists(dst) and os.path.samefile(src, dst)):            os.link(src, dst)    elif link == 'sym':        if not (os.path.exists(dst) and os.path.samefile(src, dst)):            os.symlink(src, dst)     # Otherwise (non-Mac, not linking), copy the file contents and    # (optionally) copy the times and mode.    else:        _copy_file_contents(src, dst)        if preserve_mode or preserve_times:            st = os.stat(src)             # According to David Ascher <da@ski.org>, utime() should be done            # before chmod() (at least under NT).            if preserve_times:                os.utime(dst, (st[ST_ATIME], st[ST_MTIME]))            if preserve_mode:                os.chmod(dst, S_IMODE(st[ST_MODE]))     return (dst, 1) # copy_file ()  # XXX I suspect this is Unix-specific -- need porting help!def move_file (src, dst,               verbose=0,               dry_run=0):     """Move a file 'src' to 'dst'.  If 'dst' is a directory, the file will    be moved into it with the same name; otherwise, 'src' is just renamed    to 'dst'.  Return the new full name of the file.     Handles cross-device moves on Unix using 'copy_file()'.  What about    other systems???    """    from os.path import exists, isfile, isdir, basename, dirname    import errno     log.info("moving %s -> %s", src, dst)     if dry_run:        return dst     if not isfile(src):        raise DistutilsFileError, \              "can't move '%s': not a regular file" % src     if isdir(dst):        dst = os.path.join(dst, basename(src))    elif exists(dst):        raise DistutilsFileError, \              "can't move '%s': destination '%s' already exists" % \              (src, dst)     if not isdir(dirname(dst)):        raise DistutilsFileError, \              "can't move '%s': destination '%s' not a valid path" % \              (src, dst)     copy_it = 0    try:        os.rename(src, dst)    except os.error, (num, msg):        if num == errno.EXDEV:            copy_it = 1        else:            raise DistutilsFileError, \                  "couldn't move '%s' to '%s': %s" % (src, dst, msg)     if copy_it:        copy_file(src, dst)        try:            os.unlink(src)        except os.error, (num, msg):            try:                os.unlink(dst)            except os.error:                pass            raise DistutilsFileError, \                  ("couldn't move '%s' to '%s' by copy/delete: " +                   "delete '%s' failed: %s") % \                  (src, dst, src, msg)     return dst # move_file ()  def write_file (filename, contents):    """Create a file with the specified name and write 'contents' (a    sequence of strings without line terminators) to it.    """    f = open(filename, "w")    for line in contents:        f.write(line + "\n")    f.close()