a2cloud/setup/cppo.txt

#!/usr/bin/env python
"""cppo: Copy or catalog one or all files from a ProDOS raw disk image.

copy all files:
    cppo [-ad|-e] imagefile target_directory
copy one file:
    cppo [-ad|-e] imagefile /FULL/PRODOS/FILE/PATH target_path
catalog image:
    cppo -cat imagefile

-ad : Create AppleDouble header files and preserve resource forks.
-e  : Append ProDOS type and auxtype to filenames, and copy resource
      forks, for adding to ShrinkIt archives with Nulib2
      using its -e option.

Wildcard matching/globbing (*) is not supported.
No verification or validation of the disk image is performed.

(Compatible with Python 2.6 and later, including 3.x.)
"""

# cppo by Ivan X, ivan@ivanx.com, ivanx.com/appleii

# If anyone's looking at this, and feels it's not sufficiently Pythonic,
# I know that. It's pretty much a line-for-line conversion of the original
# Bash script. I did start a beautiful from-the-ground-up object-oriented
# version, then realized it would be faster to translate it ugly and quick.

# imports for python 3 code compatibility
from __future__ import print_function
from __future__ import unicode_literals
from __future__ import absolute_import
from __future__ import division

import sys
import os
import time
import datetime

# Intentially fails on pre-2.6 so user can see what's wrong
b'ERROR: cppo requires Python 2.6 or later, including 3.x.'

class Globals(object):
    pass

g = Globals()

g.imageData = b''
g.outFileData = bytearray(b'')
g.adFileData = bytearray(b'')
g.exFileData = bytearray(b'')

g.activeDirBlock = None
g.activeFileName = None
g.activeFileSize = None
g.activeFileBytesCopied = 0
g.resourceFork = 0

g.PDOSPATH = []
g.PDOSPATH_INDEX = 0
g.PDOSPATH_SEGMENT = None
g.DIRPATH = ""

g.targetName = None
g.targetDir = ""
g.ADdir = None
g.imageFile = None

g.AD = 0
g.EX = 0
g.DIR = 0
g.silent = 0

# functions

def pdosDateToUnixDate(arg1):
    # input: ProDOS date/time bit sequence string in format:
    #   "yyyyyyymmmmddddd000hhhhh00mmmmmm" (ustr)
    # output: seconds since Unix epoch (1-Jan-1970),
    #         or current date/time if no ProDOS date
    year = (binToDec(slyce(arg1,0,7)) + 1900)
    if (year < 1940): year += 100
    month = binToDec(slyce(arg1,7,4))
    day = binToDec(slyce(arg1,11,5))
    hour = binToDec(slyce(arg1,19,5))
    minute = binToDec(slyce(arg1,26,6))
    # print(year, month, day, hour, minute)
    td = (datetime.datetime(year, month, day, hour, minute) -
           datetime.datetime(1970,1,1))
    unixDate_naive = (td.days*24*60*60 + td.seconds)
    td2 = (datetime.datetime.fromtimestamp(unixDate_naive) -
                  datetime.datetime.utcfromtimestamp(unixDate_naive))
    utcoffset = (td2.days*24*60*60 + td2.seconds)
    # print(unixDate_naive - utcoffset)
    return (unixDate_naive - utcoffset) # local time zone with DST

def unixDateToADDate(arg1):
    # input: seconds since Unix epoch (1-Jan-1970 00:00:00 GMT)
    # output: seconds since Netatalk epoch (1-Jan-2000 00:00:00 GMT),
    #         in hex-ustr (big endian)
    adDate = (arg1 - 946684800)
    if (adDate < 0 ):
        adDate += 4294967296 # to get negative hex number
    adDateHex = to_hex(adDate).zfill(8).upper()
    # print(arg1, adDate, adDateHex)
    return adDateHex

# cppo support routines:
# arg1: directory block
# arg2: file index (if applicable)
# arg3: directory chunk # (if applicable)

#most of these not tested yet in Python
# returns byte position in disk image file
def getStartPos(arg1, arg2):
    return ( (arg1 * 512) +
             (39 * ((arg2 + (arg2 > 11)) % 13)) +
             (4 if (arg2 > 11) else 43) )

def getStorageType(arg1, arg2):
    start = getStartPos(arg1, arg2)
    firstByte = readcharDec(g.imageData, start)
    return (firstByte//16)

def getFileName(arg1, arg2):
    start = getStartPos(arg1, arg2)
    firstByte = readcharDec(g.imageData, start)
    entryType = (firstByte//16)
    nameLength = (firstByte - entryType*16)
    return readchars(g.imageData, start+1, nameLength)

def getFileType(arg1, arg2):
    start = getStartPos(arg1, arg2)
    return readcharHex(g.imageData, start+16)
    
def getKeyPointer(arg1, arg2):
    start = getStartPos(arg1, arg2)
    return (readcharDec(g.imageData, start+17) +
            readcharDec(g.imageData, start+18)*256)

def getFileLength(arg1, arg2):
    start = getStartPos(arg1, arg2)
    return (readcharDec(g.imageData, start+21) +
            readcharDec(g.imageData, start+22)*256 +
            readcharDec(g.imageData, start+23)*65536)

def getAuxType(arg1, arg2):
    start = getStartPos(arg1, arg2)
    return (readcharHex(g.imageData, start+32) +
            readcharHex(g.imageData, start+31))

def getCreationDate(arg1, arg2):
    #outputs prodos creation date/time as Unix time
    #  (seconds since Jan 1 1970 GMT)
    #or None if there is none
    start = getStartPos(arg1, arg2)
    pdosDate = (hexToBin(readcharHex(g.imageData, start+25)) +
                hexToBin(readcharHex(g.imageData, start+24)) +
                hexToBin(readcharHex(g.imageData, start+27)) +
                hexToBin(readcharHex(g.imageData, start+26)))
    try:
        rVal = pdosDateToUnixDate(pdosDate)
    except Exception:
        rVal = None
    return rVal

def getModifiedDate(arg1, arg2):
    #outputs prodos modified date/time as Unix time
    #  (seconds since Jan 1 1970 GMT)
    #or None if there is none
    start = getStartPos(arg1, arg2)
    pdosDate = (hexToBin(readcharHex(g.imageData, start+34)) +
                hexToBin(readcharHex(g.imageData, start+33)) +
                hexToBin(readcharHex(g.imageData, start+36)) +
                hexToBin(readcharHex(g.imageData, start+35)))
    try:
        rVal = pdosDateToUnixDate(pdosDate)
    except Exception:
        rVal = None
    return rVal

def getVolumeName():
    return getWorkingDirName(2)

def getWorkingDirName(arg1):
    start = ( arg1 * 512 )
    firstByte = readcharDec(g.imageData, start+4)
    entryType = (firstByte//16)
    nameLength = (firstByte - entryType*16)
    return readchars(g.imageData, start+5, nameLength)

def getDirEntryCount(arg1):
    start = ( arg1 * 512 )
    return (readcharDec(g.imageData, start+37) +
            readcharDec(g.imageData, start+38)*256)

def getDirNextChunkPointer(arg1):
    start = ( arg1 * 512 )
    return (readcharDec(g.imageData, start+2) +
            readcharDec(g.imageData, start+3)*256)

# -- script begins in earnest here

def copyFile(arg1, arg2):
    g.outFileData = bytearray(b'')
    g.exFileData = bytearray(b'')
    g.activeFileBytesCopied = 0
    storageType = getStorageType(arg1, arg2)
    keyPointer = getKeyPointer(arg1, arg2)
    fileLen = getFileLength(arg1, arg2)
    if (storageType == 1): #seedling
        copyBlock(keyPointer, fileLen)
    elif (storageType == 2): #sapling
        processIndexBlock(keyPointer)
    elif (storageType == 3): #tree
        processMasterIndexBlock(keyPointer)
    elif (storageType == 5): #extended (forked)
        processForkedFile(keyPointer)

def copyBlock(arg1, arg2):
    #arg1: block to copy
    #arg2: bytes to write (should be 512,
    #      unless final block with less than 512 bytes)
    #print(arg1 + " " + arg2 + " " + g.activeFileBytesCopied)
    if (arg1 == 0):
        outBytes = (b'\x00' * arg2)
    else:
        outBytes = slyce(g.imageData, arg1*512, arg2)
    if (g.resourceFork > 0):
        if g.AD:
            g.adFileData[g.activeFileBytesCopied+741:
                        (g.activeFileBytesCopied+741 + arg2)] = outBytes
        if g.EX:
            g.exFileData[g.activeFileBytesCopied:
                        (g.activeFileBytesCopied + arg2)] = outBytes
    else:
        g.outFileData[g.activeFileBytesCopied:
                     (g.activeFileBytesCopied + arg2)] = outBytes
    g.activeFileBytesCopied += arg2

def processDir(arg1, arg2=None, arg3=None, arg4=None, arg5=None):
    # arg1: dirBlock
    # arg2/3/4/5: for non-key chunks: entryCount, entry#,
    #   workingDirName, processedEntryCount

    entryCount = None
    e = None
    pe = None
    workingDirName = None

    if arg2:
        entryCount = arg2
        e = arg3
        workingDirName = arg4
        pe = arg5
    else:
        e = 0
        pe = 0
        entryCount = getDirEntryCount(arg1)
        workingDirName = getWorkingDirName(arg1).decode("L1")
        g.DIRPATH = (g.DIRPATH + "/" + workingDirName)
        if g.PDOSPATH_INDEX:
            if (g.PDOSPATH_INDEX == 1):
                if (("/" + g.PDOSPATH_SEGMENT) != g.DIRPATH):
                    print("ProDOS volume name does not match disk image.")
                    sys.exit(2)
                else:
                    g.PDOSPATH_INDEX += 1
                    g.PDOSPATH_SEGMENT = g.PDOSPATH[g.PDOSPATH_INDEX]
        else:
            print(g.DIRPATH)
    while (pe < entryCount):
        if (getStorageType(arg1, e) > 0):
            processEntry(arg1, e)
            pe += 1
        e += 1
        if not ((e + ( e>11 ) ) % 13):
            processDir(getDirNextChunkPointer(arg1),
                       entryCount,
                       e,
                       workingDirName,
                       pe)
            break

def processEntry(arg1, arg2):
    '''
    print(getFileName(arg1, arg2), getStorageType(arg1, arg2),
          getFileType(arg1, arg2), getKeyPointer(arg1, arg2),
          getFileLength(arg1, arg2), getAuxType(arg1, arg2),
          getCreationDate(arg1, arg2), getModifiedDate(arg1, arg2))
    '''
    g.activeFileName = getFileName(arg1 ,arg2).decode("L1")
    g.activeFileSize = getFileLength(arg1, arg2)

    if ((not g.PDOSPATH_INDEX) or (g.activeFileName == g.PDOSPATH_SEGMENT)):

        if (getStorageType(arg1, arg2) == 13): # if ProDOS directory
            if not g.PDOSPATH_INDEX:
                g.targetDir = (g.targetDir + "/" + g.activeFileName)
            g.ADdir = (g.targetDir + "/.AppleDouble")
            if not (g.DIR or os.path.isdir(g.targetDir)):
                makedirs(g.targetDir)
            if not (g.DIR or (not g.AD) or os.path.isdir(g.ADdir)):
                makedirs(g.ADdir)
            if g.PDOSPATH_SEGMENT:
                g.PDOSPATH_INDEX += 1
                g.PDOSPATH_SEGMENT = g.PDOSPATH[g.PDOSPATH_INDEX]
            processDir(getKeyPointer(arg1, arg2))
            g.DIRPATH = g.DIRPATH.rsplit("/", 1)[0]
            if not g.PDOSPATH_INDEX:
                g.targetDir = g.targetDir.rsplit("/", 1)[0]
            g.ADdir = (g.targetDir + "/.AppleDouble")
        else: # if ProDOS file
            if not g.PDOSPATH_INDEX:
                print("   " + g.activeFileName)
            if g.DIR:
                return
            if not g.targetName:
                g.targetName = g.activeFileName
            if g.EX:
                eTargetName = (g.targetName + "#" +
                               getFileType(arg1, arg2).lower() +
                               getAuxType(arg1, arg2).lower())
            touch(g.targetDir + "/" + g.targetName)
            if g.AD: makeADfile()
            copyFile(arg1, arg2)
            saveFile((g.targetDir + "/" + g.targetName), g.outFileData)
            creationDate = getCreationDate(arg1, arg2)
            modifiedDate = getModifiedDate(arg1, arg2)
            if (creationDate is None and modifiedDate is not None):
                creationDate = modifiedDate
            elif (creationDate is not None and modifiedDate is None):
                modifiedDate = creationDate
            elif (creationDate is None and modifiedDate is None):
                creationDate = (datetime.datetime.today() -
                                datetime.datetime(1970,1,1)).days*24*60*60
                modifiedDate = creationDate
            if g.AD: # AppleDouble
                # set dates
                ADfilePath = (g.ADdir + "/" + g.targetName)
                writecharsHex(g.adFileData,
                              637,
                              (unixDateToADDate(creationDate) +
                               unixDateToADDate(modifiedDate)))
                writecharHex(g.adFileData, 645, "80")
                writecharHex(g.adFileData, 649, "80")
                #set type/creator
                writechars(g.adFileData, 653, b'p')
                writecharsHex(g.adFileData,
                              654,
                              (getFileType(arg1, arg2) +
                               getAuxType(arg1, arg2)))
                writechars(g.adFileData, 657, b'pdos')
                saveFile(ADfilePath, g.adFileData)
            touch((g.targetDir + "/" + g.targetName), modifiedDate)
            if g.EX: # extended name
                os.rename((g.targetDir + "/" + g.targetName),
                          (g.targetDir + "/" + eTargetName))
                if (len(g.exFileData) > 0):
                    saveFile((g.targetDir + "/" + eTargetName + "r"),
                              g.exFileData)
                    touch((g.targetDir + "/" + eTargetName + "r"),
                           modifiedDate)
            if g.PDOSPATH_SEGMENT:
                syncExit()
            g.targetName = None
    
    #else:
        #print(g.activeFileName + " doesn't match " + g.PDOSPATH_SEGMENT)

def processForkedFile(arg1):
    # finder info except type/creator
    fInfoA_entryType = readcharDec(g.imageData, 9)
    fInfoB_entryType = readcharDec(g.imageData, 27)
    if (fInfoA_entryType == 1):
        writechars(g.imageData, 661, readchars(g.imageData, 18, 8))
    elif (fInfoA_entryType == 2):
        writechars(g.imageData, 669, readchars(g.imageData, 10, 16))
    if (fInfoB_entryType == 1):
        writechars(g.imageData, 661, readchars(g.imageData, 36, 8))
    elif (fInfoB_entryType == 2):
        writechars(g.imageData, 669, readchars(g.imageData, 28, 16))

    for f in [0, 256]:
        g.resourceFork = f
        g.activeFileBytesCopied = 0
        forkStart = (arg1 * 512) # start of Forked File key block
        # print("--" + forkStart)
        forkStorageType = readcharDec(g.imageData, forkStart+f+0)
        forkKeyPointer = (readcharDec(g.imageData, forkStart+f+1) +
                          readcharDec(g.imageData, forkStart+f+2)*256)
        forkFileLen = (readcharDec(g.imageData, forkStart+f+5) +
                       readcharDec(g.imageData, forkStart+f+6)*256 +
                       readcharDec(g.imageData, forkStart+f+7)*256*256)
        g.activeFileSize = forkFileLen
        if (g.resourceFork > 0):
            rsrcForkLenHex = (readcharHex(g.imageData, forkStart+f+7) +
                              readcharHex(g.imageData, forkStart+f+6) +
                              readcharHex(g.imageData, forkStart+f+5))
            # print(">>>" + rsrcForkLenHex)
            print("    [resource fork]")
            if g.AD:
                writecharsHex(g.adFileData, 35, rsrcForkLenHex)
        else:
            print("    [data fork]")
        if (forkStorageType == 1): #seedling
            copyBlock(forkKeyPointer, forkFileLen)
        elif (forkStorageType == 2): #sapling
            processIndexBlock(forkKeyPointer)
        elif (forkStorageType == 3): #tree
            processMasterIndexBlock(forkKeyPointer)
    # print()
    g.resourceFork = 0

def processMasterIndexBlock(arg1):
    processIndexBlock(arg1, True)

def processIndexBlock(arg1, arg2=False):
    #arg1: indexBlock
    #arg2: if True, it's a Master Index Block
    pos = 0
    bytesRemaining = g.activeFileSize
    while (g.activeFileBytesCopied < g.activeFileSize):
        targetBlock = (readcharDec(g.imageData, arg1*512+pos) +
                       readcharDec(g.imageData, arg1*512+(pos+256))*256)
        if arg2:
            processIndexBlock(targetBlock)
        else:
            bytesRemaining = (g.activeFileSize - g.activeFileBytesCopied)
            bs = (bytesRemaining if (bytesRemaining < 512) else 512)
            copyBlock(targetBlock, bs)
        pos += 1
        if (pos > 255):
            break # go to next entry in Master Index Block (tree)

def makeADfile():
    if not g.AD: return
    touch(g.ADdir + "/" + g.targetName)
    g.adFileData = bytearray(b'\x00' * 741)
    # ADv2 header
    writecharsHex(g.adFileData, hexToDec("00"), "0005160700020000")
    # number of entries
    writecharsHex(g.adFileData, hexToDec("18"), "000D")
    # Resource Fork
    writecharsHex(g.adFileData, hexToDec("1A"), "00000002000002E500000000")
    # Real Name
    writecharsHex(g.adFileData, hexToDec("26"), "00000003000000B600000000")
    # Comment
    writecharsHex(g.adFileData, hexToDec("32"), "00000004000001B500000000")
    # Dates Info
    writecharsHex(g.adFileData, hexToDec("3E"), "000000080000027D00000010")
    # Finder Info
    writecharsHex(g.adFileData, hexToDec("4A"), "000000090000028D00000020")
    # ProDOS file info
    writecharsHex(g.adFileData, hexToDec("56"), "0000000B000002C100000008")
    # AFP short name
    writecharsHex(g.adFileData, hexToDec("62"), "0000000D000002B500000000")
    # AFP File Info
    writecharsHex(g.adFileData, hexToDec("6E"), "0000000E000002B100000004")
    # AFP Directory ID
    writecharsHex(g.adFileData, hexToDec("7A"), "0000000F000002AD00000004")
    # dbd (second time) will create DEV, INO, SYN, SV~

def syncExit():
    if (not g.silent and g.AD and os.path.isdir("/usr/local/etc/netatalk")):
        print("File(s) have been copied to the target directory. " +
              "If the directory")
        print("is shared by Netatalk, please type 'afpsync' now.")
    # saveFile(g.imageFile, g.imageData)
    sys.exit(0)

def usage():
    print(sys.modules[__name__].__doc__)
    sys.exit(1)

# --- ID bashbyter functions (adapted)

def decToHex(arg1):
# converts single-byte decimal value to hexadecimal equivalent
# arg: decimal value from 0-255
# out: two-digit hex string from 00-FF
#exit: 21=invalid arg
    if (arg1<0 or arg1>255): sys.exit(21)
    return to_hex(arg1).upper()

def hexToDec(arg1):
# converts single-byte hexadecimal value to decimal equivalent
# arg: two-digit hex value from 00-FF
# out: decimal value
#exit: 21=invalid arg
    if (len(arg1) != 2): return 21
    return to_dec(arg1)

def hexToBin(arg1):
# converts single-byte hexadecimal value to binary string
# arg: two-digit hex value from 00-FF
# out: binary string value
#exit: 21=invalid arg
    if (len(arg1) != 2): return 21
    return to_bin(arg1).zfill(8)

def binToDec(arg1):
# converts single-byte binary string (8 bits) value to decimal
# warning: no error checking
# arg: binary string up to 8 bits
# out: decimal value
    return to_dec([arg1])
    
def binToHex(arg1):
# converts single-byte binary string (8 bits) value to hex
# warning: no error checking
# arg: binary string up to 8 bits
# out: hex value
    return to_hex(arg1).upper()

def charToDec(arg1):
# converts single char (of type bytes) to corresponding decimal value
# arg: one char (of type bytes)
# out: decimal value from 0-255
#exit: 21=invalid arg
    if (len(arg1) != 1): return 21
    return to_dec(arg1)

def charToHex(arg1):
# converts single char (of type bytes) to corresponding hex value
# arg: one char (of type bytes)
# out: hexadecimal value from 00-FF
#exit: 21=invalid arg
    if (len(arg1) != 1): return 21
    return to_hex(arg1).upper()

def decToChar(arg1):
# converts single-byte decimal value to equivalent char (of type bytes)
# arg: decimal number from 0-255
# out: one character
#exit: 21=invalid arg
    if (arg1<0 or arg1>255): sys.exit(21)
    return to_bytes(arg1)

def hexToChar(arg1):
# converts single-byte hex value to corresponding char (of type bytes)
# arg: two-digit hexadecimal number from 00-FF
# out: one character
#exit: 21=invalid arg
    if (len(arg1) != 2): return 21
    return to_bytes(arg1)

def readchars(arg1, arg2=0, arg3=0):
# read one or more characters from a bytes variable
# arg1: bytes or bytearray variable
# arg2: (optional) offset (# of bytes to skip before reading)
# arg3: (optional) # of chars to read (default is to end of bytes var)
#  out: sequence of characters (bytes or bytearray)
# exit: 21=invalid arg1, 22=invalid arg2, 23=invalid arg3
    if not (isinstance(arg1, bytes) or isinstance(arg1, bytearray)):
        sys.exit(21)
    if (arg2<0): sys.exit(22)
    if (arg3<0): sys.exit(23)
    if (arg3 == 0):
        arg3 = len(arg1)
    return slyce(arg1, arg2, arg3)

def readcharDec(arg1, arg2=0):
# read one character from bytes var & convert to equivalent dec value
# arg1: bytes var
# arg2: (optional) offset (# of bytes to skip before reading)
#  out: decimal value from 0-255
# exit: 21=invalid arg1, 22=invalid arg2
    if not (isinstance(arg1, bytes) or isinstance(arg1, bytearray)):
        sys.exit(21)
    if (arg2<0): sys.exit(22)
    return to_dec(slyce(arg1, arg2, 1))

def readcharHex(arg1, arg2=0):
# read one character from bytes var & convert to corresponding hex value
# arg1: bytes var
# arg2: (optional) offset (# of bytes to skip before reading)
#  out: two-digit hex value from 00-FF
# exit: 21=invalid arg1, 22=invalid arg2
    if not (isinstance(arg1, bytes) or isinstance(arg1, bytearray)):
        sys.exit(21)
    if (arg2<0): sys.exit(22)
    return to_hex(slyce(arg1, arg2, 1))

def writechars(arg1, arg2, arg3):
# write one or more characters (bytes) to bytearray
# arg1: bytearray variable
# arg2: offset (# of bytes to skip before writing)
# arg3: sequence of bytes (or bytearray)
#  out: nothing
# exit: 21=invalid arg1, 22=invalid arg2, 23=invalid arg3
    if not isinstance(arg1, bytearray): sys.exit(21)
    if (arg2<0): sys.exit(22)
    if not (isinstance(arg3, bytes) or isinstance(arg3, bytearray)):
        sys.exit(23)
    arg1[arg2:arg2+len(arg3)] = arg3

def writecharDec(arg1, arg2, arg3):
# write corresponding char of single-byte decimal value into bytearray
# arg1: bytearray
# arg2: offset (# of bytes to skip before writing)
# arg3: decimal number from 0-255
# exit: 21=invalid arg1, 22=invalid arg2, 23=invalid arg3
#  out: nothing
    if not isinstance(arg1, bytearray): sys.exit(21)
    if (arg2<0): sys.exit(22)
    if not isnumber(arg3): sys.exit(23)
    arg1[arg2:arg2+1] = to_bytes(arg3)

def writecharHex(arg1, arg2, arg3):
# write corresponding character of single-byte hex value into bytearray
# arg1: bytearray
# arg2: offset (# of bytes to skip before writing)
# arg3: two-digit hexadecimal number from 00-FF
#  out: nothing
# exit: 21=invalid arg1, 22=invalid arg2, 23=invalid arg3
    if not isinstance(arg1, bytearray): sys.exit(21)
    if (arg2<0): sys.exit(22)
    if not isinstance(arg3, type("".encode().decode())): sys.exit(23)
    arg1[arg2:arg2+1] = to_bytes(arg3)

def writecharsHex(arg1, arg2, arg3):
# write corresponding characters of hex values into bytearray
# arg1: bytearray
# arg2: offset (# of bytes to skip before writing)
# arg3: string of two-digit hexadecimal numbers from 00-FF
#  out: nothing
# exit: 21=invalid arg1, 22=invalid arg2, 23=invalid arg3
    if not isinstance(arg1, bytearray): sys.exit(21)
    if (arg2<0): sys.exit(22)
    if not isinstance(arg3, type("".encode().decode())): sys.exit(23)
    arg1[arg2:arg2+len(to_bytes(arg3))] = to_bytes(arg3)

#---- IvanX general purpose functions ----#

def slyce(val, start_pos=0, length=1, reverse=False):
    """returns slice of object (but not a slice object)
    allows specifying length, and 3.x "bytes" consistency"""
    the_slyce = val[start_pos:start_pos+length]
    return (the_slyce[::-1] if reverse else the_slyce)

def to_hex(val):
    """convert bytes, decimal number, or [bin-ustr] to two-digit hex values
    unlike hex(), accepts bytes; has no leading 0x or trailing L"""
    from binascii import b2a_hex
    if isinstance(val, list): # [bin-ustr]
        val = int(val[0], 2)
    if isinstance(val, bytes): # bytes
        return b2a_hex(val).decode("L1")
    elif isnumber(val):
        # .encode().decode() always returns unicode in both P2 and P3
        return (hex(val)[2:].split("L")[0]).encode("L1").decode("L1")
    else:
        raise Exception("to_hex() requires bytes, int/long, or [bin-ustr]")

def hex_slyce(val, start_pos=0, length=1, little_endian=False):
    """returns bytes slyce as hex-ustr"""
    return to_hex(slyce(val, start_pos, length, little_endian))

def dec_slyce(val, start_pos=0, length=1, little_endian=False):
    """returns bytes slyce converted to decimal int/long"""
    return to_dec(hex_slyce(val, start_pos, length, little_endian))

def bin_slyce(val, start_pos=0, length=1, little_endian=False):
    """returns bytes slyce converted to bin-ustr"""
    return to_bin(hex_slyce(val, start_pos, length, little_endian))

def to_dec(val):
    """convert bytes, hex-ustr or [bin-ustr] to decimal int/long"""
    if isinstance(val, list): # [bin-ustr]
        return int(val[0], 2)
    elif isinstance(val, bytes): # bytes
        return int(to_hex(val), 16)
    elif isinstance(val, type("".encode().decode())): # hex-ustr
        return int(val, 16)
    else:
        raise Exception("to_dec() requires bytes, hex-ustr or [bin-ustr]")

def to_bin(val):
    """convert bytes, hex-ustr, or int/long to bin-ustr"""
    if isinstance(val, bytes): # bytes
        return (bin(to_dec(to_hex(val))))[2:].encode("L1").decode("L1")
    elif isinstance(val, type("".encode().decode())): # hex-ustr
        return (bin(int(val, 16)))[2:].encode("L1").decode("L1")
    elif isnumber(val): # int/long
        return (bin(val))[2:].encode("L1").decode("L1")
    else:
        raise Exception("to_bin() requires bytes, hex-ustr, or int/long")

def to_bytes(val):
    """converts hex-ustr, int/long, or [bin-ustr] to bytes"""
    from binascii import a2b_hex
    if isinstance(val, list): # [bin-ustr]
        val = to_hex(val[0])
    if isnumber(val): # int/long
        val = to_hex(val)
    if isinstance(val, type("".encode().decode())): # hex-ustr
        return a2b_hex(bytes(val.encode("L1"))) # works on both P2 and P3
    else:
        raise Exception(
          "to_bytes() requires hex-ustr, int/long, or [bin-ustr]")
    
def shift(items):
    """Shift list items to left, losing the first item.
    
    in : list
    out: list
    """
    for i in range(0, (len(items)-1)):
        items[i] = items[i+1]
    del items[-1]
    return items
    
def s(string):
    """Perform local variable substution, e.g. 'total: {num} items'"""
    # http://stackoverflow.com/questions/2960772/
    #        putting-a-variable-inside-a-string-python
    # http://stackoverflow.com/questions/6618795/
    #        get-locals-from-calling-namespace-in-python
    import inspect
    frame = inspect.currentframe()
    try:
        rVal = string.format(**frame.f_back.f_locals)
    finally:
        del frame
    return rVal

def get_object_names(cls, include_subclasses=True):
    object_names = []
    for (this_object_name, this_object_id) in list(globals().items()):
        if include_subclasses:
            if isinstance(this_object_id, cls):
                 object_names.append(this_object_name)
        else:
            if type(this_object_id) is cls:
                 object_names.append(this_object_name)
    return object_names

def touch(filePath, modTime=None):
    # http://stackoverflow.com/questions/1158076/implement-touch-using-python
    import os
    if (os.name == "nt"):
        if filePath[-1] == ".": filePath += "-"
        filePath = filePath.replace("./", ".-/")
    with open(filePath, "ab"):
        os.utime(filePath, (None if (modTime is None) else (modTime, modTime)))

def mkdir(dirPath):
    import os
    if (os.name == "nt"):
        if dirPath[-1] == ".": dirPath += "-"
        dirPath = dirPath.replace("./", ".-/")
    try:
        os.mkdir(dirPath)
    except FileExistsError:
        pass

def makedirs(dirPath):
    import os
    if (os.name == "nt"):
        if dirPath[-1] == ".": dirPath += "-"
        dirPath = dirPath.replace("./", ".-/")
    try:
        os.makedirs(dirPath)
    except FileExistsError:
        pass

def loadFile(filePath):
    import os
    if (os.name == "nt"):
        if filePath[-1] == ".": filePath += "-"
        filePath = filePath.replace("./", ".-/")
    with open(filePath, "rb") as imageHandle:
        return imageHandle.read()

def saveFile(filePath, fileData):
    import os
    if (os.name == "nt"):
        if filePath[-1] == ".": filePath += "-"
        filePath = filePath.replace("./", ".-/")
    with open(filePath, "wb") as imageHandle:
        imageHandle.write(fileData)

def isnumber(number):
    try: # make sure it's not a string
        len(number)
        return False
    except TypeError:
        pass
    try:
        int(number)
    except ValueError:
        return False
    return True

#---- end IvanX general purpose functions ----#


# --- start

args = sys.argv
if (len(args) == 1):
    usage()

if (args[1] == "-s"):
    g.silent=1
    args = args[1:] #shift

if (args[1] == "-ad"):
    g.AD = 1
    args = args[1:] #shift

if (args[1] == "-e"):
    if g.AD: usage()
    g.EX = 1
    args = args[1:] #shift

if (args[1] == "-cat"):
    g.DIR = 1
    args = args[1:]

if not ((g.DIR and len(args) >= 2) or (len(args) >= 3)):
    usage()
if ((len(args) == 4) and
    (slyce(args[2],0,1) != "/") and
    (slyce(args[2],0,1) != ":")):
    usage()

g.imageFile = args[1]
if not os.path.isfile(g.imageFile):
    print("Source " + g.imageFile + " was not found.")
    sys.exit(2)
g.imageData = loadFile(g.imageFile)

if (len(args) == 4):
    g.PDOSPATH = args[2].upper()
    targetPath = args[3]
    if os.path.isdir(targetPath):
        g.targetDir = targetPath
    else:
        g.targetDir = targetPath.rsplit("/", 1)[0]
        g.targetName = targetPath.rsplit("/", 1)[1]
    if not os.path.isdir(g.targetDir):
        print("Target directory not found.")
        sys.exit(2)
else:
    if not g.DIR:
        if not os.path.isdir(args[2]):
            print("Target directory not found.")
            sys.exit(2)

g.activeDirBlock = 0
g.activeFileName = ""
g.activeFileSize = 0
g.activeFileBytesCopied = 0
g.resourceFork = 0
g.PDOSPATH_INDEX = 0

if (len(args) == 4):
    g.PDOSPATH = g.PDOSPATH.replace(':', '/').split('/')
    if not g.PDOSPATH[0]:
        g.PDOSPATH_INDEX += 1
    g.PDOSPATH_SEGMENT = g.PDOSPATH[g.PDOSPATH_INDEX]
    g.ADdir = (g.targetDir + "/.AppleDouble")
    if not ((not g.AD) or os.path.isdir(g.ADdir)):
        mkdir(g.ADdir)
    processDir(2)
    print("ProDOS file not found within image file.")
    sys.exit(2)
else:
    if not g.DIR:
        # print(args[0], args[1], args[2])
        g.targetDir = (args[2] + "/" + getVolumeName().decode("L1"))
        g.ADdir = (g.targetDir + "/.AppleDouble")
        if not os.path.isdir(g.targetDir):
            makedirs(g.targetDir)
        if not ((not g.AD) or os.path.isdir(g.ADdir)):
            makedirs(g.ADdir)
    processDir(2)
    if not g.DIR:
        syncExit()