file_util.py :  » Language-Interface » ChinesePython » chinesepython2.1.3-0.4 » Lib » distutils » Python Open Source

Home
Python Open Source
1.3.1.2 Python
2.Ajax
3.Aspect Oriented
4.Blog
5.Build
6.Business Application
7.Chart Report
8.Content Management Systems
9.Cryptographic
10.Database
11.Development
12.Editor
13.Email
14.ERP
15.Game 2D 3D
16.GIS
17.GUI
18.IDE
19.Installer
20.IRC
21.Issue Tracker
22.Language Interface
23.Log
24.Math
25.Media Sound Audio
26.Mobile
27.Network
28.Parser
29.PDF
30.Project Management
31.RSS
32.Search
33.Security
34.Template Engines
35.Test
36.UML
37.USB Serial
38.Web Frameworks
39.Web Server
40.Web Services
41.Web Unit
42.Wiki
43.Windows
44.XML
Python Open Source » Language Interface » ChinesePython 
ChinesePython » chinesepython2.1.3 0.4 » Lib » distutils » file_util.py
"""distutils.file_util

Utility functions for operating on single files.
"""

# created 2000/04/03, Greg Ward (extracted from util.py)

__revision__ = "$Id: file_util.py,v 1.2 2002/04/12 09:44:04 sof34 Exp $"

import os
from stat import *
from distutils.errors import DistutilsFileError


# 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)
        
        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'.  If 'verbose' is true, then a one-line summary of the
    copy will be printed to stdout.

    '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

    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):
        if verbose:
            print "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 verbose:
        if os.path.basename(dst) == os.path.basename(src):
            print "%s %s -> %s" % (action, src, dir)
        else:
            print "%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

    if verbose:
        print "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()
www.java2java.com | Contact Us
Copyright 2009 - 12 Demo Source and Support. All rights reserved.
All other trademarks are property of their respective owners.