--- prefix.eclass	2015-08-09 09:38:18.000000000 +0900
+++ prefix.eclass.new	2016-06-29 10:45:00.101628307 +0900
@@ -25,20 +25,36 @@
 
 
 # @FUNCTION: eprefixify
-# @USAGE: <list of to be eprefixified files>
+# @USAGE: [-e <extended regex>] <list of to be eprefixified files>
 # @DESCRIPTION:
-# replaces @GENTOO_PORTAGE_EPREFIX@ with ${EPREFIX} for the given files,
-# dies if no arguments are given, a file does not exist, or changing a
+# Replaces @GENTOO_PORTAGE_EPREFIX@ with ${EPREFIX} for the given files,
+# tries a set of heuristics if @GENTOO_PORTAGE_EPREFIX@ is not found.
+# Additional extended regular expression can be passed by -e or
+# environment variable PREFIX_EXTRA_REGEX.
+# Dies if no arguments are given, a file does not exist, or changing a
 # file failed.
 eprefixify() {
 	[[ $# -lt 1 ]] && die "at least one argument required"
+	local PREFIX_EXTRA_REGEX
+	if [[ ${1} == -e ]]; then
+		PREFIX_EXTRA_REGEX="${2}"
+		shift 2
+	fi
 
+	[[ $# -lt 1 ]] && die "at least one file operand is required"
 	einfo "Adjusting to prefix ${EPREFIX:-/}"
 	local x
 	for x in "$@" ; do
 		if [[ -e ${x} ]] ; then
 			ebegin "  ${x##*/}"
-			sed -i -e "s|@GENTOO_PORTAGE_EPREFIX@|${EPREFIX}|g" "${x}"
+			if grep -qs @GENTOO_PORTAGE_EPREFIX@ "${x}" ; then
+				sed -i -e "s|@GENTOO_PORTAGE_EPREFIX@|${EPREFIX}|g" "${x}"
+			else
+				sed -r \
+					-e "s,([^[:alnum:]}])/(usr|etc|bin|sbin|var|opt)/,\1${EPREFIX}/\2/,g" \
+					-e "${PREFIX_EXTRA_REGEX}" \
+					-i "${x}"
+			fi
 			eend $? || die "failed to eprefixify ${x}"
 		else
 			die "${x} does not exist"
@@ -48,5 +64,54 @@
 	return 0
 }
 
+# @FUNCTION: __temp_prefixify
+# @USAGE: a single file. Internal use only.
+# @DESCRIPTION:
+# copies the files to ${T}, calls eprefixify, echos the new file.
+__temp_prefixify() {
+	if [[ -e $1 ]] ; then
+		local f=${1##*/}
+		cp "$1" "${T}" || die "failed to copy file"
+		eprefixify "${T}"/${f} > /dev/null
+		echo "${T}"/${f}
+	else
+		die "$1 does not exist"
+	fi
+}
+
+# @FUNCTION: fprefixify
+# @USAGE: <function> <files>
+# @DESCRIPTION:
+# prefixify a function call.
+# copies the files to ${T}, calls eprefixify, and calls the function.
+# @EXAMPLE:
+# fprefixify doexe ${FILESDIR}/fix_libtool_files.sh
+# fprefixify epatch ${FILESDIR}/${PN}-4.0.2-path.patch
+fprefixify() {
+	[[ $# -lt 2 ]] && die "at least two arguments required"
+
+	local func=$1 f
+	einfo "Adjusting ${func} to prefix ${EPREFIX:-/}"
+	shift
+	case ${func} in
+		new*)
+			[[ $# -ne 2 ]] && die "${func} takes two arguments"
+			ebegin "  ${1##*/}"
+			f=$(__temp_prefixify "$1")
+			${func} "${f}" "$2"
+			eend $? || die "failed to execute ${func}"
+			;;
+		*)
+			for x in "$@" ; do
+				ebegin "  ${x##*/}"
+				f=$(__temp_prefixify "${x}")
+				${func} "${f}"
+				eend $? || die "failed to execute ${func}"
+			done
+			;;
+	esac
+
+	return 0
+}
 
 # vim: tw=72: