fas文件格式解析

1.fas文件称为一种快速加载文件，这种文件省去了加载时的翻译时间，所以相对较快一些.
2.fas文件格式大体如下：
 

垃圾数据或其他

fas文件标识

data1size ascii)

‘$’

data1 不确定是否加密)

‘$’

data2size ascii)

‘$’

data2 加密)

keysize 1字节)

keydata

‘$’

编译时间及其他数据

 
这里面fas文件标识类似 FAS4-FILE ; Do not change it! 
 
python实现：

import os

def mixordatapl,mipl):
    for a in datapl:
        if lenmipl) < lendatapl)+1:
            mipl += mipl
    
    jiemapl = ""
    for b in rangelendatapl)):
        newpl = orddatapl[b]) ^ ordmipl[b]) ^ ordmipl[b+1])
        jiemapl += chrnewpl)
    ret = jiemapl
    
    return ret


fr = open'acad.fas', 'rb')
data = fr.read)
fr.close)

headflag = 'FAS4-FILE ; Do not change it!'



aa = data.findheadflag)
ifaa == -1):
    print 'error in find FAS4'
    sleep4)

data = data[aa-3 : ]
i1 = data.find'$')
tmp = data[34 : i1]
ee = tmp.find'
')

tlst = tmp[ : ee]
dfg = inttlst)
toupl = data[ : i1+1]

ifdfg != 1):
    ee1 = data[34 : i1]
    
    i1sta = i1+1
    de13 = ee1.find'
')
    da0lst = ee1[ : de13]
    num = intda0lst)
    i1end = i1sta + num

    i2 = i1end+1
    strdat0 = data[i1sta : i1end]
    tmpl = data[i2 : i2+50]

    i3 = i2 + tmpl.find'$') + 1;
    tmpl1 = data[i2+2 : i3]
    de32 = tmpl1.find' ')
    da1lst = tmpl1[ : de32]
    num1 = intda1lst)
    i3end = i3 + num1

    strdat1 = data[i3 : i3end]
    print i3
    keylen = orddata[i3end])
    keyend = i3end + keylen + 1
    keylst = data[i3end+1 : keyend]

    lastlst = data[keyend : ]
    zjlst = data[i2-1 : i3]


##    nstrlst0 = mixorstrdat0, keylst)
    nstrlst1 = mixorstrdat1, keylst)

    fpl1 = toupl + strdat0 + zjlst + nstrlst1 + strkeylen) + keylst + lastlst

    fw = open'a11.fas', 'wb')
    fw.writefpl1)
    fw.close)

 

Starry starry night ….