NULL mag Issue 06 29 Accessing mystic files with python

eZine lover (@eZine)

Published in 

null magazine

 · 26 Dec 2020

  

 

 
  i begun learning programming in python3, so as an exercise i made the 
  following functions to read the oneliners.dat and lastcaller.dat files. 
  it was a bitch to figure how to convert the pascal string format, cause 
  python likes to read everything as bytes, but at the end i managed to 
  make it. there is also a usefull function to unpack a DOS datetime value. 
  use the code in your own projects. i hate python, but i have to admit that 
  is something like a "universal language" in the computer tech. area. :( 
  for this reason, we should make more things with python in bbsing. 

 
--- rip here ---------------------------------------------------------------- 

#!/usr/bin/python3 
import struct 
import os 
from datetime import datetime 
datadir = "/home/x/mysa43/data/" 
  # OneLineRec = Record 
    # Text : String[79]; 
    # From : String[30]; 
  # End; 
def oneliners(): 
    f = open(datadir+"oneliner.dat","rb") # open the file 
    sf = '@b79sb30s' 
    s = struct.calcsize (sf) 
    size = struct.calcsize(sf) 
    print(size)  # size of record structure, just to know 
    i = 0 
    d = 0 
    while True: 
        line = f.read(s) # read n bytes as the record size 
        if len(line) < s: 
            break 
        i,onel,d,name = struct.unpack(sf,line)  # assign values to variables 

        # variable i contains the size of the oneliner text 
        # variable d contains the size of the user name 
        # we use the length to convert the vars onel and name to strings 
        # cause right now are byte arrays 

        print(''.join(str(name[0:d])).strip("b'"))  # print user name 
        print(''.join(str(onel[0:i])).strip("b'"))  # print text 

        print("---") 

        line = "" 

  # RecLastOn = Record    // CALLERS.DAT 
    # DateTime   : LongInt; 
    # NewUser    : Boolean; 
    # PeerIP     : String[15]; 
    # PeerHost   : String[50]; 
    # Node       : Byte; 
    # CallNum    : LongInt; 
    # Handle     : String[30];8-9 
    # City       : String[25];10-11 
    # Address    : String[30];12-13 
    # Gender     : Char;14 
    # EmailAddr  : String[35];15-16 
    # UserInfo   : String[30]; 
    # OptionData : Array[1..10] of String[60]; 
    # Reserved   : Array[1..53] of Byte; 
  # End; 

def unpackdt(t): 
      year = 1980 + (t >> 25) 
      month = (t & 0b00000001111000000000000000000000) >> 21 
      day = (t & 0b00000000000111110000000000000000) >> 16 
      hour = (t & 0b00000000000000001111100000000000) >> 11 
      minute = (t & 0b00000000000000000000011111100000) >> 5 
      second = (t & 0b00000000000000000000000000011111) * 2 
      return datetime(year, month, day, hour, minute, second) 

def lastcallers(): 
    f = open(datadir+"callers.dat","rb") 
    sf = '<L?b15sb50sBIb30sb25sb30scb35sb30s663c' 
    s = struct.calcsize (sf) 
    size = struct.calcsize(sf) 
    print(size) 
    i = 0 
    d = 0 
    while True: 
        line = f.read(s) 
        if len(line) < s: 
            break 
        res = struct.unpack(sf,line) 
        print(unpackdt(res[0])) 
        print(''.join(str(res[3][0:res[2]])).strip("b'")) 
        print(''.join(str(res[5][0:res[4]])).strip("b'")) 
        print(res[6]) 
        print(res[7]) 
        print(''.join(str(res[9][0:res[8]])).strip("b'")) 
        print(''.join(str(res[11][0:res[10]])).strip("b'")) 
        print(''.join(str(res[13][0:res[12]])).strip("b'")) 
        print(''.join(str(res[14]).strip("b'")))  # gender 
        print(''.join(str(res[16][0:res[15]])).strip("b'")) 
        print(''.join(str(res[18][0:res[17]])).strip("b'")) 
        print("---") 
        line = "" 

oneliners() 
print('-' * 79) 
lastcallers() 
-- stop ripping here --------------------------------------------------------- 
say thanks here: ___________ :p