Examine all the com.apple.macl entries on files and folders

maclTrack.command

#!/bin/bash
: <<-EOL
MIT License

Copyright (c) 2020 Joel Bruner

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
EOL

#hold down command key at launch or touch /tmp/debug to enable xtrace command expansion 
commandKeyDown=$(/usr/bin/python -c 'import Cocoa; print Cocoa.NSEvent.modifierFlags() & Cocoa.NSCommandKeyMask > 1')
[ "$commandKeyDown" == "True" -o -f /tmp/debug ] && set -x && xtraceFlag=1

#############
# VARIABLES #
#############

#header for CSV output
CSVHeader="Filename,Header,App UUID"

#the name of this script
myName=$(basename "${0}")

#############
# FUNCTIONS #
#############

function printUsage
{
echo -e "Usage: ${myName} [-d depth] [-s] target [...]"
echo -e "\nSwitches:"
echo -e "-d depth - specify the maxdepth a folder should be traversed into"
echo -e "-s - silence output for items without com.apple.macl XA"
echo -e "\nArguments:\ntarget - can be one or more files or folders, folders will be fully traversed unless a maxdepth is specified\n"
}

function processTarget
{
#strip any trailing slash off
local target="${1%/}"
local item;

IFS=$'\n'

#if directory get files
if [ -d "${target}" ]; then
	#a directory can have com.apple.macl applied to it - https://lapcatsoftware.com/articles/macl.html
    if [ -z "${maxdepth}" ]; then
	    fileList=$(find "${target}" | sort)
    else
	    fileList=$(find "${target}" -maxdepth "$maxdepth" | sort)    
    fi
elif [ -f "${target}" ]; then
    fileList="${target}"
else
	return
fi

#got through each file
for item in ${fileList}; do
	maclXA "${item}"
done
}

function maclXA
{
local file="${1}"

#if the file is not readable return
[ ! -r "$file" ] && return

#test for com.apple.macl attribute
local attributeRAW=$(xattr -p com.apple.macl "$file" 2>/dev/null)

#if there is no attribute data
if [ -z "$attributeRAW" ]; then
	#if silent flag is not set (0) print out a line, otherwise we print nothing 
	[ "${siletFlag:=0}" -eq 0 ] && echo "\"$file\",,"
	return
fi	

#create a string with no spaces and no linefeeds (unquoted is enough for bash but zsh would not do so)
local attribute=$(tr -d ' ' <<< $attributeRAW)

#subtract one because here strings always have a newline at the end
local attribute_length=$(( $(wc -c <<< "$attribute") - 1 ))

#com.apple.macl XA is allocated in 144 byte chunksUUIDs that hold up to 4 entries
#each entry is the 16 byte UUID plus 2 byte headers, 18 bytes expressed as an ASCII string is 36 characters
local possibleUUIDs=$(( $attribute_length / 36 ))

#echo "data size: $attribute_length"
#echo "Possible UUIDs: $possibleUUIDs"

#loop through the possible UUIDs
for ((i=0; i < $possibleUUIDs; i++ )); do
	#keep advancing 36 chars for each UUID slot
	local offset=$(( i * 36 ))

	#if the header is "0000" then skip otherwise observed values are "0100" and "0200" although the reason is not 
	local header=${attribute:$offset:4}
	[ "$header" == "0000" ] && continue

	#put header into an array now that we see there are different types
	local headerEntryArray[i]="$header"
	#assign 32 char string to an array entry, skipping the 4 char header
	local UUIDEntryArray[i]="${attribute:$(( $offset + 4 )):32}"
done

#loop though array and print hyphen punctuated UUID
for (( i=0; i < ${#UUIDEntryArray[@]}; i++ )); do
echo "\"$file\",${headerEntryArray[i]},${UUIDEntryArray[i]:0:8}-${UUIDEntryArray[i]:8:4}-${UUIDEntryArray[i]:12:4}-${UUIDEntryArray[i]:16:4}-${UUIDEntryArray[i]:20:12}"
done
}

########
# MAIN #
########

#options processing
while getopts ":hd:s" option; do
    case "${option}" in
        #print all certs
        'd')
            #flag vars simply need to be set or not
            maxdepth="$OPTARG"
            ;;
        's')
			siletFlag=1
            ;;
        'h')
            printUsage
            exit
            ;;
	esac
done


#shift past options so $1 is still $1 after the options are processed
shift $((OPTIND-1))

#you cannot test ${@} because multiple items appear as multiple arguments to [ (test) and it errors, so we eval an echo of it
if [ -z "$(eval echo ${@})" ]; then
    #let you know there an option or two to be had
    echo "Please provide target file(s) or folder(s) to examine..."
    exit
fi

#make our CSV header
echo "${CSVHeader}"

#only respect newlines in the for loop
IFS=$'\n'

#keep going until you can't do no more
for target in ${@}; do
    processTarget "${target}"
done