[patch] Fixed a couple bugs, 100% speed increase, support package versions that do not support a specified USE flag

euse-0.3.0_rc7-package.use-ebuild.patch (text/plain), 20.68 KB, created by Jared Hancock on 2009-08-09 20:59:11 UTC

--- /usr/bin/euse	2009-06-15 16:15:32.000000000 -0500
+++ euse	2009-08-08 23:39:09.000000000 -0500
@@ -13,6 +13,7 @@
 MAKE_GLOBALS_PATH=/etc/make.globals
 MAKE_PROFILE_PATH=/etc/make.profile
 MAKE_CONF_BACKUP_PATH=/etc/make.conf.euse_backup
+PACKAGE_USE_PATH=/etc/portage/package.use
 
 [ -z "${MODE}" ] && MODE="showhelp"		# available operation modes: showhelp, showversion, showdesc, showflags, modify
 
@@ -32,13 +33,14 @@
 			-E | --enable)         MODE="modify"; ACTION="add";;
 			-D | --disable)        MODE="modify"; ACTION="remove";;
 			-P | --prune)          MODE="modify"; ACTION="prune";;
+			-p | --package)	       MODE="modify"; shift; PACKAGE=${1};;
 			-*)
 				echo "ERROR: unknown option ${1} specified."
 				echo
 				MODE="showhelp"
 				;;
 			"%active")
-				get_useflags
+				get_portageuseflags
 				ARGUMENTS="${ARGUMENTS} ${ACTIVE_FLAGS[9]}"
 				;;
 			*)
@@ -55,6 +57,10 @@
 	exit 1
 }
 
+warn() {
+	echo "WARNING: ${1}"
+}
+
 get_real_path() {
 	set -P
 	cd "$1"
@@ -82,6 +88,7 @@
 	done
 #	[ ! -r "$(get_make_defaults)" ] && error "$(get_make_defaults) is not readable"
 	[ "${MODE}" == "modify" -a ! -w "${MAKE_CONF_PATH}" ] && error ""${MAKE_CONF_PATH}" is not writable"
+	[ "${MODE}" == "modify" -a -s "${PACKAGE_USE_PATH}" -a ! -w "${PACKAGE_USE_PATH}" ] && error ""${PACKAGE_USE_PATH}" is not writable"
 }
 
 showhelp() {
@@ -101,13 +108,17 @@
          -E, --enable         - enable the given useflags
          -D, --disable        - disable the given useflags
          -P, --prune          - remove all references to the given flags from
-                                make.conf to revert to default settings
+                                make.conf and package.use to revert to default 
+                                settings
+         -p, --package        - used with -E, -D, to apply to a specific
+                                package only
 
 Notes: ${PROGRAM_NAME} currently only works for global flags defined
-       in make.globals, make.defaults or make.conf, it doesn't handle
-       use.defaults, use.mask or package.use yet (see portage(5) for details on
-       these files). It also might have issues with cascaded profiles.
-       If multiple options are specified only the last one will be used.
+       in make.globals, make.defaults or make.conf, and local flags defined
+       in package.use and individual package ebuilds, it doesn't handle
+       use.defaults or use.mask yet (see portage(5) for details on these
+       files). It also might have issues with cascaded profiles. If 
+       multiple options are specified only the last one will be used.
 HELP
 }
 
@@ -147,13 +158,44 @@
 print ' '.join(r)" 
 }
 
+# Similar to reduce_incrementals except converts lines from package atoms
+# in /etc/portage/package.use files to lines of "pkg {[-]flag}*"
+reduce_package_use() {
+    echo "${@}" | python -c "import sys,re
+h={}; atom=re.compile(r'[<>]?=?([a-z][\w/-]+[a-z])(-[\dpr._*-]+)?', re.I); 
+getflags=re.compile(r'(-?[\w*-]+)')
+for x in sys.stdin.read().split('\n'):
+	if not x: continue
+	parts = x.lstrip().split(' ',1)
+	if len(parts)==1: continue
+	try:
+		pkg = atom.match(parts[0]).group(1)
+	except:
+		continue
+	flags = getflags.findall(parts[1])
+	if not pkg in h: h[pkg]=[]
+	r=h[pkg]
+	for x in flags:
+		if x[0] == '-' and x[1:] in r:
+			r.remove(x[1:])
+			r.append(x)
+		elif x[0] != '-' and '-'+x in r:
+			r.remove('-'+x)
+			r.append(x)
+		elif x == '-*':
+			r = h[pkg] = ['-*']
+		elif x not in r:
+			r.append(x)
+print '\n'.join([' %s %s ' % (pkg,' '.join(flgs)) for pkg,flgs in h.iteritems() if len(flgs)])"
+}
+
 # the following function creates a bash array ACTIVE_FLAGS that contains the
 # global use flags, indexed by origin: 0: environment, 1: make.conf, 
-# 2: make.defaults, 3: make.globals
+# 2: make.defaults, 3: make.globals, 4: package.use, 5: ebuild IUSE
 get_useflags() {
-	# only calculate once as calling emerge is painfully slow
+	# only calculate once 
 	[ -n "${USE_FLAGS_CALCULATED}" ] && return
-	
+
 	# backup portdir so get_portdir() doesn't give false results later
 	portdir_backup="${PORTDIR}"
 
@@ -174,10 +216,38 @@
 	USE="${ACTIVE_FLAGS[0]}"
 	PORTDIR="${portdir_backup}"
 
+	# Parse through /etc/portage/package.use
+	if [[ -d ${PACKAGE_USE_PATH} ]]; then
+		ACTIVE_FLAGS[4]="$( cat ${PACKAGE_USE_PATH}/* \
+			| sed -re "s/#.*$//" )"
+	elif [[ -e ${PACKAGE_USE_PATH} ]]; then
+		ACTIVE_FLAGS[4]="$(sed -re "/#.*$/ d" < ${PACKAGE_USE_PATH})"
+	fi
+	# Simplify ACTIVE_FLAGS[4] to be lines of pkg {[-]flag}*
+	ACTIVE_FLAGS[4]="$(reduce_package_use "${ACTIVE_FLAGS[4]}")"
+	#
+	# ACTIVE_FLAGS[5] reserved for USE flags defined in ebuilds and
+	# is generated/maintained in the get_useflaglist_ebuild() function
+	#
+	# Traverse through use.mask and use.force (0.5s)
+	#ACTIVE_FLAGS[6]=$(reduce_incrementals \
+	#	$(cat $(traverse_profile "use.mask") \
+	#		| sed -re "/^#.*$/ {d}"))
+	#ACTIVE_FLAGS[7]=$(reduce_incrementals \
+	#	$(cat $(traverse_profile "use.force") \
+	#		| sed -re "/^#.*$/ {d}"))
+
+	USE_FLAGS_CALCULATED=1
+}
+
+# Fetch USE flags reported active by Portage
+get_portageuseflags() {
+	# only calculate once as calling emerge is painfully slow
+	[ -n "${_PORTAGE_USE_FLAGS_CALCULATED}" ] && return
 	# get the currently active USE flags as seen by portage, this has to be after
 	# restoring USE or portage won't see the original environment
 	ACTIVE_FLAGS[9]="$(emerge --info | grep 'USE=' | cut -b 5- | sed -e 's:"::g')" #'
-	USE_FLAGS_CALCULATED=1
+	_PORTAGE_USE_FLAGS_CALCULATED=1
 }
 
 # get the list of all known USE flags by reading use.desc and/or use.local.desc
@@ -194,26 +264,67 @@
 		egrep "^[^# :]+:[^ ]+ +-" "${descdir}/use.local.desc" | cut -d: -f 2 | cut -d\  -f 1
 	fi
 }
+get_useflaglist_ebuild() {
+	# $1 package atom (app-editor/vim)
+	# $2 version (7.2)
+	#
+	# TODO: Scrap ${2} input. Get a folder listing of the ebuilds,
+	#		derive version from each file name and create use flag list
+	#		from each file's contents. Store by package name and
+	#		version.
+	#
+	local known=$(echo "${ACTIVE_FLAGS[5]}" | egrep "^${1};${2}")
+	if [[ -n $known ]]; then
+		# Isolate the flags part
+		echo $known | cut -d\; -f4 | cut -d\" -f2 
+		return
+	fi
+	local pkg=$(echo ${1} | cut -d/ -f2)
+	# Open the ebuild file and retrieve defined USE flags
+	[[ ! -d "$(get_portdir)/${1}" ]] && return 1
+	for file in $(get_portdir)/${1}/*.ebuild; do
+		# Crazy sed script matches IUSE variable if it spans
+		# multiple lines
+		local flags=$(sed -nr -e '/IUSE="/{;:loop;/"$/{;s/\n//g;p;q;};N;b loop;}' ${file})
+		local slot=$(grep "^SLOT=" ${file})
+		local version=$(basename ${file} | sed -re "s:${pkg}-(.+)\.ebuild:\1:")
+		ACTIVE_FLAGS[5]="${ACTIVE_FLAGS[5]}"$'\n'"${1};${version};${slot};${flags}"
+	done
+}
 
-# get all make.defaults by traversing the cascaded profile directories
-get_all_make_defaults() {
+# General method of collecting the contents of a profile
+# component by traversing through the cascading profile
+#
+# Arguments:
+# $1 - Filename (make.profile)
+# [$2] - Current directory (unspecified means to start at the top)
+traverse_profile() {
 	local curdir
 	local parent
 	local rvalue
 	
-	curdir="${1:-$(get_real_path ${MAKE_PROFILE_PATH})}"
+	curdir="${2:-$(get_real_path ${MAKE_PROFILE_PATH})}"
 	
-	[ -f "${curdir}/make.defaults" ] && rvalue="${curdir}/make.defaults ${rvalue}"
+	[ -f "${curdir}/${1}" ] && rvalue="${curdir}/${1} ${rvalue}"
 	if [ -f "${curdir}/parent" ]; then
 		for parent in $(egrep -v '(^#|^ *$)' ${curdir}/parent); do
 			pdir="$(get_real_path ${curdir}/${parent})"
-			rvalue="$(get_all_make_defaults ${pdir}) ${rvalue}"
+			rvalue="$(traverse_profile ${1} ${pdir}) ${rvalue}"
 		done
 	fi
 
 	echo "${rvalue}"
 }
 
+# get all make.defaults by traversing the cascaded profile directories
+get_all_make_defaults() {
+	if [[ -n $MAKE_DEFAULTS ]]; then
+		echo $MAKE_DEFAULTS
+		return
+	fi
+	traverse_profile "make.defaults"
+}
+
 # get the path to make.defaults by traversing the cascaded profile directories
 get_make_defaults() {
 	local curdir
@@ -238,29 +349,129 @@
 # 3: echo value for positive (and as lowercase for negative) test result, 
 # 4 (optional): echo value for "missing" test result, defaults to blank
 get_flagstatus_helper() {
-	if echo " ${ACTIVE_FLAGS[${2}]} " | grep " ${1} " > /dev/null; then
-		echo -n "${3}"
-	elif echo " ${ACTIVE_FLAGS[${2}]} " | grep " -${1} " > /dev/null; then
-		echo -n "$(echo ${3} | tr [[:upper:]] [[:lower:]])"
+	if [[ -z ${flags} ]]; then 
+		local flags=${ACTIVE_FLAGS[${2}]}
+	fi
+	local flag=$(echo " $flags " | grep -Eo " [+-]?${1} ")
+	if [[ ${flag:1:1} == "-" ]]; then
+		echo -e -n "${3}" | tr [:upper:]+ [:lower:]-
+	elif [[ -n ${flag} ]]; then
+		echo -e -n "${3}"
 	else
 		echo -n "${4:- }"
 	fi
 }
+get_flagstatus_helper_pkg() {
+	if [[ -z ${flags} ]]; then
+		local flags=$(echo " ${ACTIVE_FLAGS[${2}]} " | grep "${5} ");
+	fi
+	if [[ -z ${5} || -z ${flags} ]]; then
+		echo -e -n "${4:- }"
+		return
+	fi
+	get_flagstatus_helper "$@"
+}
+get_flagstatus_helper_ebuild() {
+	if [[ -z ${5} ]]; then 
+		echo -n "${4:- }" 
+		return
+	fi
+	#local info=$( get_useflaglist_ebuild "${5}" "${6}")
+	local flags=$(echo $2 | cut -d\" -f2) 
+	local flag=$(echo " $flags " | grep -Eo " [+-]?$1 ")
+	if [[ ${flag:1:1} == "+" ]]; then
+		echo -en "${3}"
+	elif [[ ${flag:1:1} == "-" ]]; then
+		echo -en "${3}" | tr [:upper:]+ [:lower:]-
+	elif [[ -z $flag ]]; then
+		echo -en "!"
+	else
+		echo -en "${4:- }"
+	fi
+}
 
 # prints a status string for the given flag, each column indicating the presence
 # for portage, in the environment, in make.conf, in make.defaults and in make.globals.
-# full positive value would be "[+ECDG]", full negative value would be [-ecdg],
+# full positive value would be "[+ECDG]", full negative value would be [-ecdgpb],
 # full missing value would be "[-    ]" (portage only sees present or not present)
 get_flagstatus() {
 	get_useflags
 
-	echo -n '['
-	get_flagstatus_helper "${1}" 9 "+" "-"
-	get_flagstatus_helper "${1}" 0 "E"
-	get_flagstatus_helper "${1}" 1 "C"
-	get_flagstatus_helper "${1}" 2 "D"
-	get_flagstatus_helper "${1}" 3 "G"
-	echo -n '] '
+	local E=$(get_flagstatus_helper "${1}" 0 "E")
+	local C=$(get_flagstatus_helper "${1}" 1 "C")
+	local D=$(get_flagstatus_helper "${1}" 2 "D")
+	local G=$(get_flagstatus_helper "${1}" 3 "G")
+	#
+	# Use flag precedence is defined (at least) at:
+	# http://www.gentoo.org/doc/en/handbook/handbook-x86.xml?part=2&chap=2
+	for location in "E" "C" "D" "G"; do
+		if [[ ${!location} == $location ]]; then
+			local ACTIVE="+"
+			break
+		elif [[ ${!location} != " " ]]; then 
+			local ACTIVE="-"
+			break
+		fi
+	done
+	echo -n "[${ACTIVE:--}$E$C$D$G] "
+	if [[ $ACTIVE == "+" ]]; then
+		return 0
+	else
+		return 1
+	fi
+}
+
+get_flagstatus_pkg() {
+	# Arguments:
+	# $1 - flag (gtk)
+	# $2 - package atom (www-client/elinks)
+	# $3 - +/- whether flag is enabled by global configuration files
+	#
+	# Pre-cache the use flags declared in ebuilds first.
+	# This is required as calling it inside a $() seems to
+	# prevent caching of results into $ACTIVE_FLAGS array
+	get_useflaglist_ebuild ${2} > /dev/null
+	#
+	# Fetch list of package ebuilds matching the query from equery.
+	# 	Since determining the current version of a package requires
+	#	scanning for available ones, inpecting the KEYWORDS variable
+	#	and then checking in a heap of other places for exceptions,
+	#   equery is a simple alternative
+	#
+	echo "${ACTIVE_FLAGS[5]}" | grep $2 | while read pkgline; do
+		# This is a bit crazy, but faster than calling equery
+		OIFS=$IFS; IFS=";"; INFO=($pkgline); IFS=$OIFS;
+		local version=${INFO[1]}
+		local slot=${INFO[2]}
+		local iuse=${INFO[3]}
+		if [[ $slot == 'SLOT="0"' || $slot == "" ]]; then 
+			slot=""; 
+		else
+			slot="($(echo ${slot} | cut -d\" -f2)) "
+		fi
+		# 
+		# Fetch enabled status for this version
+		local P=$(get_flagstatus_helper_pkg "${1}" 4 "P" "" "${2}" "${version}")
+		local B=$(get_flagstatus_helper_ebuild "${1}" "${iuse}" "B" "" "${2}" "${version}")
+		ACTIVE=; UNUSED=
+		for location in "P" "B"; do
+			if [[ ${!location} == $location ]]; then
+				ACTIVE="+"
+				break
+			elif [[ ${!location} == "!" ]]; then 
+				UNUSED=1
+			elif [[ ${!location} != " " ]]; then 
+				ACTIVE="-"
+				break
+			fi
+		done
+		if [[ $UNUSED ]]; then
+			echo "          -   ${slot}${version}"
+		else
+			echo "        [${ACTIVE:-${3:- }}$P$B] ${slot}${version}"
+		fi
+	done
+	echo
 }
 
 # faster replacement to `portageq portdir`
@@ -285,6 +496,7 @@
 	local found_one
 	local args
 	
+	set -f
 	args="${*:-*}"
 	
 	if [ -z "${SCOPE}" ]; then
@@ -299,7 +511,7 @@
 	[ "${SCOPE}" == "global" ] && echo "global use flags (searching: ${args})"
 	[ "${SCOPE}" == "local" ] && echo "local use flags (searching: ${args})"
 	echo "************************************************************"
-	
+	set +f
 	if [ "${args}" == "*" ]; then
 		args="$(get_useflaglist | sort -u)"
 	fi
@@ -327,9 +539,15 @@
 					pkg="$(echo $line | cut -d\| -f 1)"
 					flag="$(echo $line | cut -d\| -f 2)"
 					desc="$(echo $line | cut -d\| -f 3)"
-					get_flagstatus "${flag}"
-					printf "%s (%s):\n%s\n\n" "${flag}" "${pkg}" "${desc}"
+					if get_flagstatus "${flag}"; then
+						ACTIVE="+"
+					else
+						ACTIVE="-"
+					fi
+					printf "%s\n    %s: %s\n" "${flag}" "${pkg}" "${desc}"
+					get_flagstatus_pkg "${flag}" "${pkg}" "${ACTIVE}"
 				done
+				echo
 		fi
 		shift
 	done
@@ -351,8 +569,8 @@
 	args=("${@:-*}")
 
 	case "${SCOPE}" in
-		"global") echo "global use flags (searching: ${args})";;
-		 "local") echo "local use flags (searching: ${args})";;
+		"global") echo "global use flags (searching: ${args[@]})";;
+		 "local") echo "local use flags (searching: ${args[@]})";;
 		       *) SCOPE="global" showinstdesc "${args[@]}"
 		          echo
 		          SCOPE="local" showinstdesc "${args[@]}"
@@ -366,7 +584,7 @@
 		args="$(get_useflaglist | sort -u)"
 	fi
 	
-	set "${args[@]}"
+	set ${args[@]}
 	
 	while [ -n "${1}" ]; do
 		case "${SCOPE}" in
@@ -394,10 +612,10 @@
 					# print name only if package is installed
 					# NOTE: If we implement bug #114086 's enhancement we can just use the
 					#       exit status of equery instead of a subshell and pipe to wc -l
-					if [ $(equery -q -C list -i -e "${pkg}" | wc -l) -gt 0 ]; then
+					if [ $(equery -q -C list -i "${pkg}" | wc -l) -gt 0 ]; then
 						foundone=1
 						IFS="$OIFS"
-						get_flagstatus "${flag}"
+						get_flagstatus "${flag}" "${pkg}"
 						IFS=': '
 						printf "%s (%s):\n%s\n\n" "${flag}" "${pkg}" "${desc#- }"
 					fi
@@ -428,11 +646,20 @@
 	set ${args}
 	
 	while [ -n "${1}" ]; do
+		get_portageuseflags
 		if echo " ${ACTIVE_FLAGS[9]} " | grep " ${1} " > /dev/null; then
 			printf "%-20s" ${1}
 			get_flagstatus ${1}
 			echo
 		fi
+		if echo " ${ACTIVE_FLAGS[4]} " | egrep -e " -?${1} " > /dev/null; then
+			for pkg in $( echo "${ACTIVE_FLAGS[4]}" | \
+					egrep " -?${1} " | cut -d " " -f 2); do
+				printf "%-20s" ${1}
+				SCOPE="local" get_flagstatus ${1} "${pkg}"
+				printf "(%s)\n" ${pkg}
+			done;
+		fi
 		shift
 	done
 }
@@ -446,9 +673,163 @@
 	NEW_MAKE_CONF_USE="${NEW_MAKE_CONF_USE// ${1} / }"
 }
 
+# Simple utility to remove empty files from package.use
+clean_package_use() {
+if [[ -d ${PACKAGE_USE_PATH} ]]; then
+	for f in $(find ${PACKAGE_USE_PATH} -size 0); do
+		echo "Removing empty file ""${f}"""
+		rm ${f}
+	done;
+fi
+}
+
+# Utility to remove a use flag from a file in package.use[/]
+# Args: (1) File, (2) Use flag
+scrub_use_flag() {
+	local atom_re="^[<>]?=?([a-z][\da-z/-]+[a-z])(-[0-9pr._*-]+)?"
+	local filename=${1}
+	# Ignore leading - on flag
+	local flag=${2#*-}
+	local pkg=$(echo "${PACKAGE}" | sed -re "s/${atom_re}/\1/")
+	local pkg_re="[<>]?=?${pkg}(-[\dpr._*-]+)?"
+
+	while read line; do
+		# Skip (preserve) comments on their own lines
+		if [[ -z $(echo "${line}" | sed -re "s/^ *#.*$//") ]]; then
+			echo "${line}"
+		# Detect if requested package is defined on this line
+		elif [[ -n ${PACKAGE} ]]; then
+			if [[ -n $(echo ${line} | grep -Ee "[^#]*${pkg_re}") ]]; then	
+				# If this is the only (remaining) use flag defined
+                # for this package, then remove the whole line
+                if [[ -z $(echo ${line} | \
+						grep -Pe "^[^#]*${pkg_re}[ ]*-?${flag}[ ]$") ]]; then
+					# Remove flag from this line
+					echo "${line}" | sed -re "s/-?\b${flag}\b//"
+				fi
+			else
+				# Passthru
+				echo "${line}"
+			fi
+		# If line only has this use flag, let it be removed 
+		# (used if PACKAGE is not defined -- from pruning)
+		elif [[ -z $(echo ${line} | \
+				grep -re "[^#]*${atom_re}.*-?${flag}") ]]; then
+			# Remove flag from this line
+			echo "${line}" | sed -re "s/-?\b${flag}\b//"
+		else
+			# Passthru
+			echo "${line}"
+		fi;
+	done < <(cat "${filename}") > "${filename}";
+}
+
+modify_package() {
+	get_useflags
+
+	local atom_re="^[<>]?=?([a-z][\da-z/-]+[a-z])(-[0-9pr._*-]+)?"
+	local pkg=$(echo "${PACKAGE}" | sed -re "s/${atom_re}/\1/")
+	local pkg_re="[<>]?=?${pkg}(-[\dpr._*-]+)?"
+
+	while [[ -n ${1} ]]; do
+	local flag=${1}
+	#
+	# --- Sanity checks
+	# (1) make sure ${pkg} exists in portdir
+	if [[ ! -d "$(get_portdir)/${pkg}" ]]; then
+		error "Package ""${pkg}"" does not exist"
+	#
+	# (2) make sure ${flag} is defined in get_useflaglist
+	elif [[ ! -n $(echo " $(get_useflaglist) " | grep "${flag}") ]]; then
+		warn "USE flag ""${flag}"" does not exist"
+		# Don't bail just because of this, just warn
+	fi;
+	# If flag is enabled in portage USE flags (emerge --info), 
+	# then "remove"ing the flag should be replaced with adding
+	# the negative flag instead
+	if [[ "${ACTION}" == "remove" &&
+			-z $( echo " ${ACTIVE_FLAGS[4]} " | egrep -e " ${PACKAGE}.*${flag}\b" ) &&
+			$( get_flagstatus ${flag} ${pkg} | grep "+" ) ]]; then
+		flag="-${flag}"
+		ACTION="add"
+	# If flag is currently disabled for the package requested 
+	# to be enabled in, then "remove" the negative
+	elif [[ "${ACTION}" == "add" &&
+			-n $( echo " ${ACTIVE_FLAGS[4]} " | egrep -e " ${PACKAGE}.*-${flag}\b" ) ]]; then
+		flag="-${flag}"
+		ACTION="remove"
+	fi;
+	case "${ACTION}" in
+		"add")
+			local filename
+			if [[ -d ${PACKAGE_USE_PATH} ]]; then
+				# Use naming convention of package.use/package
+				filename="${PACKAGE_USE_PATH}/${pkg#*/}"
+				if [[ ! -s "${filename}" ]]; then
+					# Create new file to contain flag
+					echo "${PACKAGE} ${flag}" > "${filename}"
+					echo "Adding ""${PACKAGE}:${flag}"" use flag to new file ""${filename}"""
+					return
+				fi;
+			else	
+				# Add to package.use file instead
+				filename=${PACKAGE_USE_PATH}
+				# Create as necessary
+				touch "${filename}"
+			fi;
+			# Walk through the file and add the flag manually
+			echo "Adding ""${PACKAGE}:${flag}"" use flag in ""${filename}"""
+            local added=0
+			while read line; do
+				if [[ -n $(echo "${line}" | egrep -e "^[^#]*${pkg_re}") ]]; then
+					echo "$(reduce_package_use "${line} ${flag}" | cut -d " " -f 2-)"
+					added=1
+				else
+					# Passthru
+					echo "${line}"
+				fi;
+			done < <(cat "${filename}") > ${filename}
+			if [[ ${added} == 0 ]]; then
+				echo "${PACKAGE} ${flag}" >> "${filename}"
+			fi
+			;;
+		"remove")
+			local filename
+			if [[ -d ${PACKAGE_USE_PATH} ]]; then
+				# Scan for file containing named package and use flag
+				filename=$( egrep -rle "${pkg_re}.*[^-]${flag}( |$)" "${PACKAGE_USE_PATH}")
+				if [[ -z "${filename}" ]]; then
+					error ""${flag}" is not defined for package "${PACKAGE}""
+					return
+				fi;
+			else
+				# Remove from package.use instead
+				filename=${PACKAGE_USE_PATH}
+				# Create as necessary
+				touch "${filename}"
+			fi;
+			# Scrub use flag from matched files
+			for f in ${filename}; do
+				# Remove current flags in file
+				echo "Removing ""${PACKAGE}:${flag}"" use flag in ""${f}"""
+				scrub_use_flag ${f} ${flag}
+			done;
+			# Remove empty files
+			clean_package_use
+			;;
+	esac;
+	shift;
+	done;
+}
+
 # USE flag modification function. Mainly a loop with calls to add_flag and 
 # remove_flag to create a new USE string which is then inserted into make.conf.
 modify() {
+	if [[ -n ${PACKAGE} ]]; then
+		modify_package ${*}
+		return;
+	fi;
+
 	if [ -z "${*}" ]; then
 		if [ "${ACTION}" != "prune" ]; then
 			echo "WARNING: no USE flags listed for modification, do you really"
@@ -488,6 +869,22 @@
 			elif echo " ${NEW_MAKE_CONF_USE} " | grep " -${1} " > /dev/null; then
 				remove_flag "-${1}"
 			fi
+			# Locate use flag in package.use
+			local filename
+			if [[ -d ${PACKAGE_USE_PATH} ]]; then
+				filename=$( egrep -rle "-?\b${1}\b" "${PACKAGE_USE_PATH}")
+			else
+				# Scrub from package.use file
+				filename=${PACKAGE_USE_PATH}
+			fi
+			# Scrub use flag from matched files
+			for f in ${filename}; do
+				# Remove current flags in file
+				echo "Disabling ""${1}"" use flag in ""${f}"""
+				scrub_use_flag ${f} ${1} 
+			done;
+			# Remove empty files from package.use
+			clean_package_use
 			shift
 		fi
 	done
@@ -545,6 +942,7 @@
 set -f
 parse_arguments "$@"
 check_sanity
+set +f
 
 eval ${MODE} ${ARGUMENTS}
-set +f
+