chgrpacl

#!/bin/bash

# 
# chgrpacl -R oldgrp newgrp file
# 
# Update ACLs on files/directories to change ACEs from one group name to
# another. Only changes ACEs for the old group name, it doesn't create new ACEs.
# 
# Requires 'aclfind'.
# 
# v0.1   - 2013-03-05 - Morgan Aldridge <morgant@makkintosshu.com>
#                       Initial version.
# 

function main () {
	# do we have 'findacl'
	if ! which findacl 1>/dev/null; then
		echo "$0 requires findacl!" 1>&2
		exit 1
	fi
	
	# are we recursive?
	local depth="-depth 0"
	if [ "$1" = "-R" ]; then
		depth=""
		shift
	fi
	
	# were we given enough parameters?
	if [ $# -ne 3 ]; then
		echo "An invalid number of parameters was specified!" 1>&2
		exit 1
	fi
	local old_group="$1"
	local new_group="$2"
	local path="$3"
	
	# get all the filenames & their ACLs for file that have ACEs for the specified old group name
	local line
	local file
	while IFS= read -r line; do
		# parse the ACEs or filename
		if [[ "$line" =~ ^\ ([0-9]+):\ ((user|group):)?([A-Za-z0-9._-]+)\ ((local|inherited)\ )?(allow|deny)\ ([a-z_,]+)$ ]]; then
			local num="${BASH_REMATCH[1]}"
			local type="${BASH_REMATCH[3]}"
			local name="${BASH_REMATCH[4]}"
			local inherited="${BASH_REMATCH[6]}"
			local grant="${BASH_REMATCH[7]}"
			local permissions="${BASH_REMATCH[8]}"
			
			#echo "#: $num; TYPE: $type; NAME: $name; GRANT: $grant; PERMISSIONS: $permissions"
			
			# rewrite the ACL with the new group name
			local tmp_old_group="$old_group"
			local tmp_new_group="$new_group"
			if [ -n "$type" ]; then
				tmp_old_group="${type}:${tmp_old_group}"
				tmp_new_group="${type}:${tmp_new_group}"
			fi
			if [ "$inherited" = "inherited" ]; then
				chmod =ai# ${num} "${tmp_new_group} ${grant} ${permissions}" "$file"
			else
				chmod =a# ${num} "${tmp_new_group} ${grant} ${permissions}" "$file"
			fi
			if [ $? -eq 0 ]; then
				echo " ${num}: ${tmp_old_group} ${inherited} ${grant} ${permissions}  -->  ${num}: ${tmp_new_group} ${inherited} ${grant} ${permissions}"
			else
				echo " ERROR! Unable to change ACE '${num}: ${tmp_old_group} ${inherited} ${grant} ${permissions}'!" 1>&2
			fi
		elif [[ "$line" =~ ^[^\ ] ]]; then
			file="$line"
			echo "$file"
		fi
	done <<< "$(findacl "$path" $depth -acegroup "$old_group" -printacl)"
}

main "$@"