diff --git a/Pmodules/bash b/Pmodules/bash
index e5e6aa0..9f0bf8f 100644
--- a/Pmodules/bash
+++ b/Pmodules/bash
@@ -8,8 +8,34 @@ if [ ${BASH_VERSINFO:-0} -lt 3 ]; then
 	return 1
 fi
 
+############################################################################
+# some sanity checks
+#
+if [[ ! -d ${PMODULES_ROOT} ]]; then
+        echo "Oops: ${PMODULES_ROOT}: Set as Pmodules root, but this is not a directory." 1>&2
+        return 1
+fi
+if [[ ! -d ${PMODULES_HOME} ]]; then
+        echo "Oops: ${PMODULES_HOME}: Set as Pmodules home, but this is not a directory." 1>&2
+        return 1
+fi
+
 #############################################################################
-# implement module comand as function
+# initialize bash completion
+#
+if [[ -r "${PMODULES_HOME}/init/bash_completion" ]]; then
+	source "${PMODULES_HOME}/init/bash_completion"
+fi
+
+#############################################################################
+# legacy...
+#
+unset MODULE_VERSION
+unset MODULE_VERSION_STACK
+unset MODULESHOME
+
+#############################################################################
+# implement module comand as shell function
 #
 module() {
 	unset BASH_ENV
@@ -56,125 +82,6 @@ module() {
 }
 export -f module
 
-#############################################################################
-# helper functions
-#
-std::append_path () {
-	local -r P="$1"
-	local -r d="$2"
-
-        if ! echo ${!P} | egrep -q "(^|:)${d}($|:)" ; then
-		if [[ -z ${!P} ]]; then
-			eval $P=\"${d}\"
-		else
-			eval $P=\"${!P}:${d}\"
-        	fi
-	fi
-}
-
-#
-# Replace or remove a directory in a path variable.
-#
-# To remove a dir:
-#	std::replace_path PATH <pattern>
-#
-# To replace a dir:
-#	std::replace_path PATH <pattern> /replacement/path
-#
-# Args:
-#	$1 name of the shell variable to set (e.g. PATH)
-#	$2 a grep pattern identifying the element to be removed/replaced
-#	$3 the replacement string (use "" for removal)
-#
-# Based on solution published here:
-# https://stackoverflow.com/questions/273909/how-do-i-manipulate-path-elements-in-shell-scripts 
-#
-std::replace_path () {
-	local -r path="$1"
-	local -r removepat="$2"
-	local -r replacestr="$3"
-
-	local -r removestr=$(echo "${!path}" | tr ":" "\n" | grep -m 1 "^$removepat\$")
-	export $path="$(echo "${!path}" | tr ":" "\n" | sed "s:^${removestr}\$:${replacestr}:" |
-                   sed '/^\s*$/d' | tr "\n" ":" | sed -e 's|^:||' -e 's|:$||')"
-}
-
-save_env() {
-	local s=''
-	while (( $# > 0 )); do
-		s+="$( typeset -p $1 );"
-		shift
-	done
-	echo export PMODULES_ENV=$( "${PMODULES_HOME}/sbin/base64" --wrap=0 <<< "$s" )	
-}
-
-############################################################################
-# some sanity checks
-#
-if [[ ! -d ${PMODULES_ROOT} ]]; then
-        echo "Oops: ${PMODULES_ROOT}: Set as Pmodules root, but this is not a directory." 1>&2
-        return 1
-fi
-if [[ ! -d ${PMODULES_HOME} ]]; then
-        echo "Oops: ${PMODULES_HOME}: Set as Pmodules home, but this is not a directory." 1>&2
-        return 1
-fi
-
-#############################################################################
-# setup environment
-#
-declare -x LOADEDMODULES=''
-declare -x _LMFILES_=''
-declare -x MODULEPATH=''
-declare -x PMODULES_USED_GROUPS
-for group in ${PMODULES_DEFAULT_GROUPS//:/ }; do
-	std::append_path MODULEPATH "${PMODULES_ROOT}/${group}/${PMODULES_MODULEFILES_DIR}"
-        std::append_path PMODULES_USED_GROUPS "${group}"
-done
-declare -x UsedReleases=''
-for r in ${PMODULES_DEFAULT_RELEASES//:/ }; do
-	std::append_path UsedReleases "${r}"
-done
-
-#eval $(save_env UsedReleases PMODULES_DEFAULT_RELEASES PMODULES_DEFAULT_GROUPS PMODULES_DEFINED_RELEASES)
-unset UsedReleases
-#unset PMODULES_DEFAULT_RELEASES
-#unset PMODULES_DEFAULT_GROUPS
-#unset PMODULES_DEFINED_RELEASES
-
-std::replace_path PATH    "${PMODULES_HOME%/*}/.*"
-std::replace_path MANPATH "${PMODULES_HOME%/*}/.*"
-std::append_path  PATH    "${PMODULES_HOME}/bin"
-
-if [[ -r /etc/man.config ]]; then
-	declare _manconf='/etc/man.config'
-elif [[ -r /etc/man.conf ]]; then
-	declare _manconf='/etc/man.conf'
-fi
-if [[ -n ${_manconf} ]]; then
-	while read name value rest; do
-		std::append_path MANPATH "${value}"
-	done < <(grep "^MANPATH\s" "${_manconf}")
-	unset _manconf
-else
-	std::append_path  MANPATH "${PMODULES_HOME}/share/man"
-	std::append_path  MANPATH "/usr/share/man"
-fi
-
-#############################################################################
-# initialize bash completion
-#
-if [[ -r "${PMODULES_HOME}/init/bash_completion" ]]; then
-	source "${PMODULES_HOME}/init/bash_completion"
-fi
-
-#############################################################################
-# legacy...
-#
-unset MODULE_VERSION
-unset MODULE_VERSION_STACK
-unset MODULESHOME
-
 # Local Variables:
 # mode: sh
 # sh-basic-offset: 8
diff --git a/Pmodules/libmodules.tcl b/Pmodules/libmodules.tcl
index e15f31c..05d114b 100644
--- a/Pmodules/libmodules.tcl
+++ b/Pmodules/libmodules.tcl
@@ -28,7 +28,6 @@ proc module-addgroup { group } {
 	global version
 
 	debug "called with arg $group"
-	set Variant [file join {*}$::variant]
 
 	set	GROUP [string toupper $group]
 	regsub -- "-" ${GROUP} "_" GROUP
@@ -41,14 +40,18 @@ proc module-addgroup { group } {
 	if { [module-info mode load] } {
 		debug "mode is load"
                 foreach overlay $::PmodulesOverlays {
-                        set dir $overlay/$group/$::PmodulesModulfilesDir/$Variant
+                        set dir [file join \
+                                     $overlay \
+                                     $group \
+                                     $::PmodulesModulfilesDir \
+                                     {*}$::variant]
                         if { [file isdirectory $dir] } {
                                 prepend-path MODULEPATH $dir
                         }
                 }
-		prepend-path PMODULES_USED_GROUPS $group
+		prepend-path UsedGroups $group
 		debug "mode=load: new MODULEPATH=$env(MODULEPATH)"
-		debug "mode=load: new PMODULES_USED_GROUPS=$env(PMODULES_USED_GROUPS)"
+		debug "mode=load: new UsedGroups=$env(UsedGroups)"
 	} elseif { [module-info mode remove] } {
 		set GROUP [string toupper $group]
 		debug "remove hierarchical group '${GROUP}'"
@@ -70,17 +73,25 @@ proc module-addgroup { group } {
 		}
 		debug "mode=remove: $env(MODULEPATH)"
                 foreach overlay $::PmodulesOverlays {
-                        remove-path MODULEPATH $overlay/$group/$::PmodulesModulfilesDir/$Variant
+                        remove-path MODULEPATH [file join \
+                                                    $overlay \
+                                                    $group \
+                                                    $::PmodulesModulfilesDir \
+                                                    {*}$::variant]
                 }
 		debug "mode=remove: $env(PMODULES_USED_GROUPS)"
-		remove-path PMODULES_USED_GROUPS $group
+		remove-path UsedGroups $group
 	}
 	if { [module-info mode switch2] } {
 		debug "mode=switch2"
                 foreach overlay $::PmodulesOverlays {
-                        append-path MODULEPATH $overlay/$group/$::PmodulesModulfilesDir/[module-info name]
+                        append-path MODULEPATH  [file join \
+                                                     $::PmodulesRoot \
+                                                     $group \
+                                                     $::PmodulesModulfilesDir \
+                                                     [module-info name]]
                 }
-		append-path PMODULES_USED_GROUPS ${group}
+		append-path UsedGroups ${group}
 	}
 }
 
diff --git a/Pmodules/libstd.bash b/Pmodules/libstd.bash
index 1773f17..ad7f0e6 100644
--- a/Pmodules/libstd.bash
+++ b/Pmodules/libstd.bash
@@ -67,16 +67,16 @@ std::get_abspath() {
 }
 
 std::append_path () {
-        local -r P=$1
-        local -r d=$2
+	local -r P="$1"
+	local -r d="$2"
 
         if ! echo ${!P} | egrep -q "(^|:)${d}($|:)" ; then
-                if [[ -z ${!P} ]]; then
-                        eval $P=${d}
-                else
-                        eval $P=${!P}:${d}
-                fi
-        fi
+		if [[ -z ${!P} ]]; then
+			eval $P=\"${d}\"
+		else
+			eval $P=\"${!P}:${d}\"
+        	fi
+	fi
 }
 
 std::prepend_path () {
@@ -105,6 +105,33 @@ std::remove_path() {
 	eval ${P}="${new_path:1}"
 }
 
+#
+# Replace or remove a directory in a path variable.
+#
+# To remove a dir:
+#	std::replace_path PATH <pattern>
+#
+# To replace a dir:
+#	std::replace_path PATH <pattern> /replacement/path
+#
+# Args:
+#	$1 name of the shell variable to set (e.g. PATH)
+#	$2 a grep pattern identifying the element to be removed/replaced
+#	$3 the replacement string (use "" for removal)
+#
+# Based on solution published here:
+# https://stackoverflow.com/questions/273909/how-do-i-manipulate-path-elements-in-shell-scripts 
+#
+std::replace_path () {
+	local -r path="$1"
+	local -r removepat="$2"
+	local -r replacestr="$3"
+
+	local -r removestr=$(echo "${!path}" | tr ":" "\n" | grep -m 1 "^$removepat\$")
+	export $path="$(echo "${!path}" | tr ":" "\n" | sed "s:^${removestr}\$:${replacestr}:" |
+                   sed '/^\s*$/d' | tr "\n" ":" | sed -e 's|^:||' -e 's|:$||')"
+}
+
 #
 # split file name
 #
diff --git a/Pmodules/modulecmd.bash.in b/Pmodules/modulecmd.bash.in
index 0b057f4..bf8e968 100755
--- a/Pmodules/modulecmd.bash.in
+++ b/Pmodules/modulecmd.bash.in
@@ -76,7 +76,7 @@ pbuild::save_env() {
 	pbuild::export_env ${shell} PMODULES_ENV
 }
 
-trap 'pbuild::save_env ${g_shell} Overlays PMODULES_OVERLAYS GroupDepths UsedReleases UseFlags PMODULES_DEFAULT_GROUPS PMODULES_DEFINED_RELEASES PMODULES_DEFAULT_RELEASES' EXIT
+trap 'pbuild::save_env ${g_shell} Overlays PMODULES_OVERLAYS GroupDepths UsedReleases UseFlags UsedGroups PMODULES_DEFAULT_GROUPS PMODULES_DEFINED_RELEASES PMODULES_DEFAULT_RELEASES' EXIT
 
 print_version() {
 	echo "
@@ -504,8 +504,7 @@ is_group () {
 	# not yet cached or not a group
         local overlay=''
         get_overlay_of_group overlay "${group}" || return 1
-	get_group_depths "${root}" "${group}"
-        return 0
+	get_group_depths "${overlay}" "${group}"
 }
 
 #
@@ -534,7 +533,7 @@ find_overlay () {
 }
 
 is_used_group() {
-	[[ :${PMODULES_USED_GROUPS}: =~ :$1: ]]
+	[[ :${UsedGroups}: =~ :$1: ]]
 }
 
 module_is_loaded() {
@@ -1161,7 +1160,7 @@ subcommand_avail() {
 get_group_depth () {
 	local -r group="$1"
 	local -r dir="${group}/${PMODULES_MODULEFILES_DIR}"
-	test -d "${dir}" || return 0
+	test -d "${dir}" || return 1
 	local  tmp=$(find "${dir}" -depth -type f -o -type l 2>/dev/null| head -1)
 	local -a tmp2=( ${tmp//\// } )
 	local depth=${#tmp2[@]}
@@ -1233,7 +1232,7 @@ subcommand_use() {
 		local f
 		local r
 		std::info "Used groups:\n"
-		for f in ${PMODULES_USED_GROUPS//:/ }; do
+		for f in ${UsedGroups//:/ }; do
 			std::info "\t${f}\n"
 		done
 		std::info "\nUnused groups:\n"
@@ -1283,6 +1282,9 @@ subcommand_use() {
 	}
 
 	use () {
+		declare -g UsedGroups
+		declare -g MODULEPATH
+		
 		local dirs_to_add=()
 		while (( $# > 0)); do
 			arg="$1"
@@ -1311,7 +1313,7 @@ subcommand_use() {
                                         Overlays[${overlay}]=1
                                         PMODULES_OVERLAYS="${PMODULES_OVERLAYS}:${overlay}"
 	                                get_group_depths "${!Overlays[@]}"
-                                        for group in ${PMODULES_USED_GROUPS//:/ }; do
+                                        for group in ${UsedGroups//:/ }; do
                                                 local dir="${overlay}/${group}/${PMODULES_MODULEFILES_DIR}"
                                                 if [[ -d "${dir}" ]]; then
                                                         std::prepend_path MODULEPATH "${dir}"
@@ -1324,9 +1326,9 @@ subcommand_use() {
 					std::die 3 "%s %s: cannot add group to module path -- %s\n" \
                                                  "${CMD}" "${FUNCNAME[0]##*_}" "${arg}"
 				fi
-				std::append_path PMODULES_USED_GROUPS "${arg}"
+				std::append_path UsedGroups "${arg}"
                                 for overlay in "${!Overlays[@]}"; do
-                                        for group in ${PMODULES_USED_GROUPS//:/ }; do
+                                        for group in ${UsedGroups//:/ }; do
                                                 local dir="${overlay}/"
                                                 dir+="${group}/${PMODULES_MODULEFILES_DIR}"
                                                 if [[ -d "${dir}" ]]; then
@@ -1346,7 +1348,7 @@ subcommand_use() {
 			shift
 		done
 
-		pbuild::export_env ${g_shell} MODULEPATH PMODULES_USED_GROUPS
+		pbuild::export_env ${g_shell} MODULEPATH UsedGroups
 	}
 
 	local opts=()
@@ -1439,7 +1441,7 @@ subcommand_unuse() {
 				std::die 3 "%s %s: cannot remove group from module path -- %s\n" \
                                          "${CMD}" "${FUNCNAME[0]##*_}" "${arg}"
 			fi
-			std::remove_path PMODULES_USED_GROUPS "${arg}"
+			std::remove_path UsedGroups "${arg}"
 			dirs_to_remove+=( ${modulefiles_dir} )
                        
 		elif [[ -d ${arg} ]]; then
@@ -1455,8 +1457,8 @@ subcommand_unuse() {
 		shift
 	done
 
-	declare -gx PMODULES_USED_GROUPS
-	pbuild::export_env ${g_shell} PMODULES_USED_GROUPS
+	declare -gx UsedGroups
+	pbuild::export_env ${g_shell} UsedGroups
 	[[ ${#dirs_to_remove[@]} == 0 ]] && return
 	for dir in "${dirs_to_remove[@]}"; do
 		subcommand_generic1 unuse "${dir}"
@@ -1492,13 +1494,20 @@ reset_modulepath() {
 }
 
 reset_used_groups() {
-	PMODULES_USED_GROUPS=''
+	UsedGroups=''
         local group
         for group in ${PMODULES_DEFAULT_GROUPS}; do
-                std::append_path PMODULES_USED_GROUPS "${group}"
+                std::append_path UsedGroups "${group}"
         done
 }
 
+reset_used_releases() {
+	declare -g  UsedReleases=''
+	for r in ${PMODULES_DEFAULT_RELEASES//:/ }; do
+		std::append_path UsedReleases "${r}"
+	done
+}
+
 ##############################################################################
 #
 # purge
@@ -1507,7 +1516,7 @@ subcommand_purge() {
 	subcommand_generic0 purge "$@"
         reset_modulepath
         reset_used_groups
-	pbuild::export_env ${g_shell} MODULEPATH PMODULES_USED_GROUPS
+	pbuild::export_env ${g_shell} MODULEPATH UsedGroups
 }
 
 ##############################################################################
@@ -1544,21 +1553,51 @@ subcommand_list() {
 	"${modulecmd}" "${g_shell}" list "${opts[@]}"
 }
 
+init_path() {
+        std::replace_path PATH    "${PMODULES_HOME%/*}/.*"
+        std::append_path  PATH    "${PMODULES_HOME}/bin"
+}
+
+init_manpath() {
+        std::replace_path MANPATH "${PMODULES_HOME%/*}/.*"
+
+        if [[ -r /etc/man.config ]]; then
+	        declare _manconf='/etc/man.config'
+        elif [[ -r /etc/man.conf ]]; then
+	        declare _manconf='/etc/man.conf'
+        fi
+        if [[ -n ${_manconf} ]]; then
+	        while read name value rest; do
+		        std::append_path MANPATH "${value}"
+	        done < <(grep "^MANPATH\s" "${_manconf}")
+	        unset _manconf
+        else
+	        std::append_path  MANPATH "${PMODULES_HOME}/share/man"
+	        std::append_path  MANPATH "/usr/share/man"
+        fi
+}
+
 ##############################################################################
 pmodules_init() {
-	declare -g LOADEDMODULES=''
-	declare -g _LMFILES_=''
+	declare -gx LOADEDMODULES=''
+	declare -gx _LMFILES_=''
 
         declare -Ag Overlays=([${PMODULES_ROOT}]="1")
-        declare -xg PMODULES_OVERLAYS="${PMODULES_ROOT}"
+        declare -gx PMODULES_OVERLAYS="${PMODULES_ROOT}"
+	declare -g  UsedGroups=''
+	declare -gx MODULEPATH=''
 	declare -Ag GroupDepths='()'
-	declare -g  UsedReleases=''
 	declare -g  UseFlags=()
-	for r in ${PMODULES_DEFAULT_RELEASES//:/ }; do
-		std::append_path UsedReleases "${r}"
-	done
         reset_modulepath
         reset_used_groups
+        reset_used_releases
+        init_path
+        init_manpath
+        pbuild::export_env "${g_shell}" \
+                           LOADEDMODULES \
+                           _LMFILES_ \
+                           MODULEPATH \
+                           PATH
 }
 
 ##############################################################################
@@ -1582,7 +1621,7 @@ subcommand_clear() {
 		esac
 	done
 	pmodules_init
-	pbuild::export_env ${g_shell} LOADEDMODULES PMODULES_USED_GROUPS MODULEPATH _LMFILES_
+	pbuild::export_env ${g_shell} LOADEDMODULES MODULEPATH _LMFILES_
 }
 
 ##############################################################################
@@ -1658,6 +1697,7 @@ subcommand_search() {
 		local -r tmpfile=$( "${mktemp}" /tmp/Pmodules.XXXXXX ) \
 		    || std::die 1 "Oops: unable to create tmp file!\n"
 		local group
+		# loop over all groups
 		for group in "${!GroupDepths[@]}"; do
 			# loop over all directories which can be added to
 			# MODULEPATH inside current group