1 #
2 # Copyright (c) 2001 Bizar Software Pty Ltd (http://www.bizarsoftware.com.au/)
3 # This module is free software, and you may redistribute it and/or modify
4 # under the same terms as Python, so long as this copyright message and
5 # disclaimer are retained in their original form.
6 #
7 # IN NO EVENT SHALL BIZAR SOFTWARE PTY LTD BE LIABLE TO ANY PARTY FOR
8 # DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING
9 # OUT OF THE USE OF THIS CODE, EVEN IF THE AUTHOR HAS BEEN ADVISED OF THE
10 # POSSIBILITY OF SUCH DAMAGE.
11 #
12 # BIZAR SOFTWARE PTY LTD SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
13 # BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
14 # FOR A PARTICULAR PURPOSE. THE CODE PROVIDED HEREUNDER IS ON AN "AS IS"
15 # BASIS, AND THERE IS NO OBLIGATION WHATSOEVER TO PROVIDE MAINTENANCE,
16 # SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
17 #
18 # $Id: install_util.py,v 1.11 2006-01-25 03:11:43 richard Exp $
20 """Support module to generate and check fingerprints of installed files.
21 """
22 __docformat__ = 'restructuredtext'
24 import os, sha, shutil
26 sgml_file_types = [".xml", ".ent", ".html"]
27 hash_file_types = [".py", ".sh", ".conf", ".cgi"]
28 slast_file_types = [".css"]
30 digested_file_types = sgml_file_types + hash_file_types + slast_file_types
32 def extractFingerprint(lines):
33 # get fingerprint from last line
34 if lines[-1].startswith("#SHA: "):
35 # handle .py/.sh comment
36 return lines[-1][6:].strip()
37 elif lines[-1].startswith("<!-- SHA: "):
38 # handle xml/html files
39 fingerprint = lines[-1][10:]
40 fingerprint = fingerprint.replace('-->', '')
41 return fingerprint.strip()
42 elif lines[-1].startswith("/* SHA: "):
43 # handle css files
44 fingerprint = lines[-1][8:]
45 fingerprint = fingerprint.replace('*/', '')
46 return fingerprint.strip()
47 return None
49 def checkDigest(filename):
50 """Read file, check for valid fingerprint, return TRUE if ok"""
51 # open and read file
52 inp = open(filename, "r")
53 lines = inp.readlines()
54 inp.close()
56 fingerprint = extractFingerprint(lines)
57 if fingerprint is None:
58 return 0
59 del lines[-1]
61 # calculate current digest
62 digest = sha.new()
63 for line in lines:
64 digest.update(line)
66 # compare current to stored digest
67 return fingerprint == digest.hexdigest()
70 class DigestFile:
71 """ A class that you can use like open() and that calculates
72 and writes a SHA digest to the target file.
73 """
75 def __init__(self, filename):
76 self.filename = filename
77 self.digest = sha.new()
78 self.file = open(self.filename, "w")
80 def write(self, data):
81 lines = data.splitlines()
82 # if the file is coming from an installed tracker being used as a
83 # template, then we will want to re-calculate the SHA
84 fingerprint = extractFingerprint(lines)
85 if fingerprint is not None:
86 data = '\n'.join(lines[:-1]) + '\n'
87 self.file.write(data)
88 self.digest.update(data)
90 def close(self):
91 file, ext = os.path.splitext(self.filename)
93 if ext in sgml_file_types:
94 self.file.write("<!-- SHA: %s -->\n" % (self.digest.hexdigest(),))
95 elif ext in hash_file_types:
96 self.file.write("#SHA: %s\n" % (self.digest.hexdigest(),))
97 elif ext in slast_file_types:
98 self.file.write("/* SHA: %s */\n" % (self.digest.hexdigest(),))
100 self.file.close()
103 def copyDigestedFile(src, dst, copystat=1):
104 """ Copy data from `src` to `dst`, adding a fingerprint to `dst`.
105 If `copystat` is true, the file status is copied, too
106 (like shutil.copy2).
107 """
108 if os.path.isdir(dst):
109 dst = os.path.join(dst, os.path.basename(src))
111 dummy, ext = os.path.splitext(src)
112 if ext not in digested_file_types:
113 if copystat:
114 return shutil.copy2(src, dst)
115 else:
116 return shutil.copyfile(src, dst)
118 fsrc = None
119 fdst = None
120 try:
121 fsrc = open(src, 'r')
122 fdst = DigestFile(dst)
123 shutil.copyfileobj(fsrc, fdst)
124 finally:
125 if fdst: fdst.close()
126 if fsrc: fsrc.close()
128 if copystat: shutil.copystat(src, dst)
131 def test():
132 import sys
134 testdata = open(sys.argv[0], 'r').read()
136 for ext in digested_file_types:
137 testfile = "__digest_test" + ext
139 out = DigestFile(testfile)
140 out.write(testdata)
141 out.close()
143 assert checkDigest(testfile), "digest ok w/o modification"
145 mod = open(testfile, 'r+')
146 mod.seek(0)
147 mod.write('# changed!')
148 mod.close()
150 assert not checkDigest(testfile), "digest fails after modification"
152 os.remove(testfile)
155 if __name__ == '__main__':
156 test()
158 # vim: set filetype=python ts=4 sw=4 et si