1## demonstrates using BackupRead and BackupWrite to copy all of a file's data streams
2
3import win32file, win32api, win32con, win32security, ntsecuritycon
4from win32com import storagecon
5import pythoncom, pywintypes
6import struct, traceback
7from pywin32_testutil import str2bytes, ob2memory
8
9all_sd_info = (
10 win32security.DACL_SECURITY_INFORMATION
11 | win32security.DACL_SECURITY_INFORMATION
12 | win32security.OWNER_SECURITY_INFORMATION
13 | win32security.GROUP_SECURITY_INFORMATION
14)
15
16tempdir = win32api.GetTempPath()
17tempfile = win32api.GetTempFileName(tempdir, "bkr")[0]
18outfile = win32api.GetTempFileName(tempdir, "out")[0]
19print("Filename:", tempfile, "Output file:", outfile)
20
21f = open(tempfile, "w")
22f.write("some random junk" + "x" * 100)
23f.close()
24
25## add a couple of alternate data streams
26f = open(tempfile + ":streamdata", "w")
27f.write("data written to alternate stream" + "y" * 100)
28f.close()
29
30f = open(tempfile + ":anotherstream", "w")
31f.write("z" * 100)
32f.close()
33
34## add Summary Information, which is stored as a separate stream
35m = storagecon.STGM_READWRITE | storagecon.STGM_SHARE_EXCLUSIVE | storagecon.STGM_DIRECT
36pss = pythoncom.StgOpenStorageEx(
37 tempfile, m, storagecon.STGFMT_FILE, 0, pythoncom.IID_IPropertySetStorage, None
38)
39ps = pss.Create(
40 pythoncom.FMTID_SummaryInformation,
41 pythoncom.IID_IPropertyStorage,
42 0,
43 storagecon.STGM_READWRITE | storagecon.STGM_SHARE_EXCLUSIVE,
44)
45ps.WriteMultiple(
46 (storagecon.PIDSI_KEYWORDS, storagecon.PIDSI_COMMENTS), ("keywords", "comments")
47)
48ps = None
49pss = None
50
51## add a custom security descriptor to make sure we don't
52## get a default that would always be the same for both files in temp dir
53new_sd = pywintypes.SECURITY_DESCRIPTOR()
54sid = win32security.LookupAccountName("", "EveryOne")[0]
55acl = pywintypes.ACL()
56acl.AddAccessAllowedAce(1, win32con.GENERIC_READ, sid)
57acl.AddAccessAllowedAce(1, ntsecuritycon.FILE_APPEND_DATA, sid)
58acl.AddAccessAllowedAce(1, win32con.GENERIC_WRITE, sid)
59acl.AddAccessAllowedAce(1, ntsecuritycon.FILE_ALL_ACCESS, sid)
60
61new_sd.SetSecurityDescriptorDacl(True, acl, False)
62win32security.SetFileSecurity(tempfile, win32security.DACL_SECURITY_INFORMATION, new_sd)
63
64
65sa = pywintypes.SECURITY_ATTRIBUTES()
66sa.bInheritHandle = True
67h = win32file.CreateFile(
68 tempfile,
69 win32con.GENERIC_ALL,
70 win32con.FILE_SHARE_READ,
71 sa,
72 win32con.OPEN_EXISTING,
73 win32file.FILE_FLAG_BACKUP_SEMANTICS,
74 None,
75)
76
77outh = win32file.CreateFile(
78 outfile,
79 win32con.GENERIC_ALL,
80 win32con.FILE_SHARE_READ | win32con.FILE_SHARE_WRITE,
81 sa,
82 win32con.OPEN_EXISTING,
83 win32file.FILE_FLAG_BACKUP_SEMANTICS,
84 None,
85)
86
87ctxt = 0
88outctxt = 0
89buf = None
90readsize = 100
91
92while 1:
93 bytes_read, buf, ctxt = win32file.BackupRead(h, readsize, buf, False, True, ctxt)
94 if bytes_read == 0:
95 break
96 bytes_written, outctxt = win32file.BackupWrite(
97 outh, bytes_read, buf, False, True, outctxt
98 )
99 print("Written:", bytes_written, "Context:", outctxt)
100win32file.BackupRead(h, 0, buf, True, True, ctxt)
101win32file.BackupWrite(outh, 0, str2bytes(""), True, True, outctxt)
102win32file.CloseHandle(h)
103win32file.CloseHandle(outh)
104
105assert open(tempfile).read() == open(outfile).read(), "File contents differ !"
106assert (
107 open(tempfile + ":streamdata").read() == open(outfile + ":streamdata").read()
108), "streamdata contents differ !"
109assert (
110 open(tempfile + ":anotherstream").read() == open(outfile + ":anotherstream").read()
111), "anotherstream contents differ !"
112assert (
113 ob2memory(win32security.GetFileSecurity(tempfile, all_sd_info))[:]
114 == ob2memory(win32security.GetFileSecurity(outfile, all_sd_info))[:]
115), "Security descriptors are different !"
116## also should check Summary Info programatically