libstd.bash: upvar replaced with reference variables

Pmodules/libstd.bash

@@ -78,41 +78,42 @@ std::get_abspath() {
 }
 
 std::append_path () {
-	local -r P=$1
-	local -r d=$2
+        local -nr P="$1"
+	shift 1
+	local dir
+	local dirs=''
+	for dir in "$@"; do
+		[[ "${P}" == @(|*:)${dir}@(|:*) ]] && continue
+		dirs+=":${dir}"
+	done
 
-        if ! echo ${!P} | egrep -q "(^|:)${d}($|:)" ; then
-		if [[ -z ${!P} ]]; then
-			export "$P=${d}"
-		else
-			export "$P=${!P}:${d}"
-        	fi
-	fi
+        if [[ -z ${P} ]]; then
+                P="${dirs:1}"		# remove leading ':'
+        else
+		P="${P}${dirs}"
+        fi
 }
 
 std::prepend_path () {
         local -nr P="$1"
 	shift 1
-	local path="$1"
-	shift 1
+
 	local dir
+	local dirs=''
+	for dir in "$@"; do
+		[[ "${P}" == @(|*:)${dir}@(|:*) ]] && continue
+		dirs+="${dir}:"
+	done
 
         if [[ -z ${P} ]]; then
-		for dir in "$@"; do
-			path+=":${dir}"
-		done
-                P="${path}"
+                P="${dirs:0:-1}"	# remove trailing ':'
         else
-		for dir in "$@"; do
-			[[ "${P}" == @(|*:)${dir}@(|:*) ]] && continue
-			path+=":${dir}"
-		done
-		P="${path}:${P}"
+		P="${dirs}${P}"
         fi
 }
 
 std::remove_path() {
-        local -r P=$1
+        local -nr P="$1"
 	shift 1
         local -ar dirs="$@"
 	local new_path=''
@@ -124,8 +125,7 @@ std::remove_path() {
 			[[ "${entry}" != "${dir}" ]] && new_path+=":${entry}"
 		done
 	done
-	# remove leading ':'
-	std::upvar "$P" "${new_path:1}"
+	P="${new_path:1}"		# remove leading ':'
 }
 
 #
@@ -175,22 +175,23 @@ std::replace_path () {
 #     analog to std::split_abspath() with a relative path.
 #
 std::split_path() {
-	local parts="$1"
-	local  -r path="$2"
+	local -n parts="$1"
+	local -r path="$2"
 
         IFS='/'
         local std__split_path_result=( ${std__split_path_tmp} )
 	unset IFS
-	std::upvar ${parts} "${std__split_path_result[@]}"
+	parts="${std__split_path_result[@]}"
 	if (( $# >= 3 )); then
 		# return number of parts
-	        std::upvar "$3" ${#std__split_path_result[@]}
+		local -n num="$3"
+	        num="${#std__split_path_result[@]}"
 	fi
 }
 
 std::split_abspath() {
-	local parts="$1"
-	local  -r path="$2"
+	local -n parts="$1"
+	local -r path="$2"
 	if [[ "${path:0:1}" == '/' ]]; then
 		local -r std__split_path_tmp="${path:1}"
 	else
@@ -200,16 +201,17 @@ std::split_abspath() {
         IFS='/'
         local std__split_path_result=( ${std__split_path_tmp} )
 	unset IFS
-	std::upvar ${parts} "${std__split_path_result[@]}"
+	parts="${std__split_path_result[@]}"
 	if (( $# >= 3 )); then
 		# return number of parts
-	        std::upvar "$3" ${#std__split_path_result[@]}
+		local -n num="$3"
+	        num="${#std__split_path_result[@]}"
 	fi
 }
 
 std::split_relpath() {
-	local parts="$1"
-	local  -r path="$2"
+	local -n parts="$1"
+	local -r path="$2"
 	if [[ "${path:0:1}" == '/' ]]; then
 		std::die 255 "Oops: Internal error in '${FUNCNAME[0]}' called by '${FUNCNAME[1]}' }"
 	else
@@ -219,10 +221,11 @@ std::split_relpath() {
         IFS='/'
         local std__split_path_result=( ${std__split_path_tmp} )
 	unset IFS
-	std::upvar ${parts} "${std__split_path_result[@]}"
+	parts="${std__split_path_result[@]}"
 	if (( $# >= 3 )); then
 		# return number of parts
-	        std::upvar "$3" ${#std__split_path_result[@]}
+		local -n num="$3"
+	        num="${#std__split_path_result[@]}"
 	fi
 }