1 files changed, 44 insertions, 0 deletions
diff --git a/eclass/fixheadtails.eclass b/eclass/fixheadtails.eclass
new file mode 100644
index 000000000000..2bac496375b5
--- /dev/null
+++ b/eclass/fixheadtails.eclass
@@ -0,0 +1,44 @@
+# Copyright 1999-2014 Gentoo Foundation
+# Distributed under the terms of the GNU General Public License v2
+# $Id$
+
+# @ECLASS: fixheadtails.eclass
+# @MAINTAINER:
+# base-system@gentoo.org
+# @AUTHOR:
+# Original author John Mylchreest <johnm@gentoo.org>
+# @BLURB: functions to replace obsolete head/tail with POSIX compliant ones
+
+DEPEND=">=sys-apps/sed-4"
+
+_do_sed_fix() {
+	einfo " - fixed $1"
+	sed -i \
+		-e 's/head \+-\([0-9]\)/head -n \1/g' \
+		-e 's/tail \+\([-+][0-9]\+\)c/tail -c \1/g' \
+		-e 's/tail \+\([-+][0-9]\)/tail -n \1/g' ${1} || \
+			die "sed ${1} failed"
+}
+
+# @FUNCTION: ht_fix_file
+# @USAGE: <files>
+# @DESCRIPTION:
+# Fix all the specified files.
+ht_fix_file() {
+	local i
+	einfo "Replacing obsolete head/tail with POSIX compliant ones"
+	for i in "$@" ; do
+		_do_sed_fix "$i"
+	done
+}
+
+# @FUNCTION: ht_fix_all
+# @DESCRIPTION:
+# Find and fix all files in the current directory as needed.
+ht_fix_all() {
+	local MATCHES
+	MATCHES=$(grep -l -s -i -R -e "head -[ 0-9]" -e "tail [+-][ 0-9]" * | sort -u)
+	[[ -n ${MATCHES} ]] \
+		&& ht_fix_file ${MATCHES} \
+		|| einfo "No need for ht_fix_all anymore !"
+}