Question

I’m trying out regex (import re) to extract the info I want from a log file.

UPDATE: Added the C:\WINDOWS\security folder permissions which broke all of the sample codes.

Say the format of the log is:

C:\:
    BUILTIN\Administrators  Allowed:    Full Control
    NT AUTHORITY\SYSTEM Allowed:    Full Control
    BUILTIN\Users   Allowed:    Read & Execute
    BUILTIN\Users   Allowed:    Special Permissions: 
            Create Folders
    BUILTIN\Users   Allowed:    Special Permissions: 
            Create Files
    \Everyone   Allowed:    Read & Execute
    (No auditing)

C:\WINDOWS\system32:
    BUILTIN\Users   Allowed:    Read & Execute
    BUILTIN\Power Users Allowed:    Modify
    BUILTIN\Power Users Allowed:    Special Permissions: 
            Delete
    BUILTIN\Administrators  Allowed:    Full Control
    NT AUTHORITY\SYSTEM Allowed:    Full Control
    (No auditing)

C:\WINDOWS\system32\config:
    BUILTIN\Users   Allowed:    Read & Execute
    BUILTIN\Power Users Allowed:    Read & Execute
    BUILTIN\Administrators  Allowed:    Full Control
    NT AUTHORITY\SYSTEM Allowed:    Full Control
    (No auditing)

C:\WINDOWS\security:
    BUILTIN\Users   Allowed:    Special Permissions: 
            Traverse Folder
            Read Attributes
            Read Permissions
    BUILTIN\Power Users Allowed:    Special Permissions: 
            Traverse Folder
            Read Attributes
            Read Permissions
    BUILTIN\Administrators  Allowed:    Full Control
    NT AUTHORITY\SYSTEM Allowed:    Full Control
    (No auditing)

And it repeats for a few other directories. How can I split them into paragraphs and then check for lines containing Special Permissions:?

Like this:

1. Separate the whole string1 into few parts, C:\ and C:\WINDOWS\system32.
2. Look in each line that contains ‘Special Permissions:’
3. Display the whole line, e.g.:
   C:\:
BUILTIN\Users Allowed: Special Permissions: \n\
Create Folders\n\
BUILTIN\Users Allowed: Special Permissions: \n\
Create Files\n\
4. Repeat for next ‘paragraph’

I was thinking of:
1. Search the whole text file for r"(\w+:\\)(\w+\\?)*:" – return me the path
2. String function or regex to get the rest of the output
3. Remove all the other lines besides the ones with Special Permissions
4. Display, and repeat step 1

But I think it is not efficient.

Can anyone guide me on this? Thanks.

---

Example output:

C:\:
BUILTIN\Users   Allowed:    Special Permissions:
Create Folders
BUILTIN\Users   Allowed:    Special Permissions:
Create Files

C:\WINDOWS\system32:
BUILTIN\Power Users Allowed:    Special Permissions: 
Delete

C:\WINDOWS\security:
BUILTIN\Users   Allowed:    Special Permissions: 
Traverse Folder
Read Attributes
Read Permissions
BUILTIN\Power Users Allowed:    Special Permissions: 
Traverse Folder
Read Attributes
Read Permissions

C:\WINDOWS\system32\config doesn’t show up as there’s no Special Permission in the lines.

---

The template I am using:

import re

text = ""

def main():
    f = open('DirectoryPermissions.xls', 'r')
    global text
    for line in f:
        text = text + line
    f.close
    print text

def regex():
    global text
    <insert code here>

if __name__ == '__main__':
    main()
    regex()

---

Answer 1

Thanks to milkypostman, scoffey, and the rest I came up with the solution:

def regex():
    global text
    for paragraph in text.split('\n\n'):
        lines = paragraph.split('\n', 1)
        #personal modifier to choose certain output only
        if lines[0].startswith('C:\\:') or lines[0].startswith('C:\\WINDOWS\system32:') or lines[0].startswith('C:\\WINDOWS\\security:'):
            print lines[0]
            iterables = re.finditer(r".*Special Permissions: \n(\s+[a-zA-Z ]+\n)*", lines[1])
            for items in iterables:
                #cosmetic fix
                parsedText = re.sub(r"\n$", "", items.group(0))
                parsedText = re.sub(r"^\s+", "", parsedText)
                parsedText = re.sub(r"\n\s+", "\n", parsedText)
                print parsedText
            print

I will still go through all of the posted codes (esp. scoffey’s as I never knew pure string manipulation is that powerful). Thanks for the insight!

Of course, this will not be the most optimal, but it works for my case. If you have any suggestions, do feel free to post.

---

Output:

C:\Python27>openfile.py
C:\:
BUILTIN\Users   Allowed:        Special Permissions:
Create Folders
BUILTIN\Users   Allowed:        Special Permissions:
Create Files

C:\WINDOWS\security:
BUILTIN\Users   Allowed:        Special Permissions:
Traverse Folder
Read Attributes
Read Permissions
BUILTIN\Power Users     Allowed:        Special Permissions:
Traverse Folder
Read Attributes
Read Permissions

C:\WINDOWS\system32:
BUILTIN\Power Users     Allowed:        Special Permissions:
Delete