send2trash/send2trash/plat_other.py

# Copyright 2010 Hardcoded Software (http://www.hardcoded.net)

# This software is licensed under the "BSD" License as described in the "LICENSE" file, 
# which should be included with this package. The terms are also available at 
# http://www.hardcoded.net/licenses/bsd_license

# This is a reimplementation of plat_other.py with reference to the
# freedesktop.org trash specification:
#   [1] http://www.freedesktop.org/wiki/Specifications/trash-spec
#   [2] http://www.ramendik.ru/docs/trashspec.html
# See also:
#   [3] http://standards.freedesktop.org/basedir-spec/basedir-spec-latest.html
#
# For external volumes this implementation will raise an exception if it can't
# find or create the user's trash directory.

import sys
import os
import os.path as op
import logging
from datetime import datetime
import stat

FILES_DIR = 'files'
INFO_DIR = 'info'
INFO_SUFFIX = '.trashinfo'

# Default of ~/.local/share [3]
XDG_DATA_HOME = os.environ.get('XDG_DATA_HOME') or '~/.local/share'
HOMETRASH = op.expanduser(op.join(XDG_DATA_HOME,'Trash'))

uid = os.getuid()
TOPDIR_TRASH = '.Trash'
TOPDIR_FALLBACK = '.Trash-' + str(uid)

def is_parent(parent, path):
    path = op.abspath(path)
    parent = op.abspath(parent)
    while path != '/':
        path = op.abspath(op.join(path, '..'))
        if path == parent:
            return True
    return False

def format_date(date):
    return date.strftime("%Y-%m-%dT%H:%M:%S")

def info_for(src, topdir):
    # ...it MUST not include a ".."" directory, and for files not "under" that
    # directory, absolute pathnames must be used. [2]
    if topdir == None or not is_parent(topdir, src):
        src = op.abspath(src)
    else:
        src = op.relpath(src, topdir)

    info  = "[Trash Info]\n"
    info += "Path=" + src + "\n"
    info += "DeletionDate=" + format_date(datetime.now()) + "\n"
    return info

def check_create(dir):
    # use 0700 for paths [3]
    if not op.exists(dir):
        os.makedirs(dir, 0o700)

def trash_move(src, dst, topdir=None):
    filename = op.basename(src)
    filespath = op.join(dst, FILES_DIR)
    infopath = op.join(dst, INFO_DIR)
    base_name, ext = op.splitext(filename)

    counter = 0
    destname = filename
    while op.exists(op.join(filespath, destname)) or op.exists(op.join(infopath, destname + INFO_SUFFIX)):
        counter += 1
        destname = '%s %s%s' % (base_name, counter, ext)
    
    check_create(filespath)
    check_create(infopath)
    
    os.rename(src, op.join(filespath, destname))
    f = open(op.join(infopath, destname + INFO_SUFFIX), 'w')
    f.write(info_for(src, topdir))
    f.close()

def find_mount_point(path):
    # Even if something's wrong, "/" is a mount point, so the loop will exit.
    path = op.abspath(path) # Required to avoid infinite loop
    while not op.ismount(path):
        path = op.split(path)[0]
    return path

def find_ext_volume_global_trash(volume_root):
    # from [2] Trash directories (1) check for a .Trash dir with the right
    # permissions set.
    trash_dir = op.join(volume_root, TOPDIR_TRASH)
    if not op.exists(trash_dir):
        return None
    
    mode = os.lstat(trash_dir).st_mode
    # vol/.Trash must be a directory, cannot be a symlink, and must have the
    # sticky bit set.
    if not op.isdir(trash_dir) or op.islink(trash_dir) or not (mode & stat.S_ISVTX):
        return None

    trash_dir = op.join(trash_dir, str(uid))
    try:
        check_create(trash_dir)
    except OSError:
        return None
    return trash_dir

def find_ext_volume_fallback_trash(volume_root):
    # from [2] Trash directories (1) create a .Trash-$uid dir.
    trash_dir = op.join(volume_root, TOPDIR_FALLBACK)
    # Try to make the directory, if we can't the OSError exception will escape
    # be thrown out of send2trash.
    check_create(trash_dir)
    return trash_dir

def find_ext_volume_trash(volume_root):
    trash_dir = find_ext_volume_global_trash(volume_root)
    if trash_dir == None:
        trash_dir = find_ext_volume_fallback_trash(volume_root)
    return trash_dir

def send2trash(path):
    if not isinstance(path, str):
        path = str(path, sys.getfilesystemencoding())
    try:
        trash_move(path, HOMETRASH, XDG_DATA_HOME)
    except OSError:
        # Check if we're on an external volume
        mount_point = find_mount_point(path)
        dest_trash = find_ext_volume_trash(mount_point)
        trash_move(path, dest_trash, mount_point)