#!/bin/sh # # $OpenBSD: reverse-blocks.sh,v 1.1 2015/11/24 04:04:19 tedu Exp $ # test if tail grep the correct number of blocks from a file. DIR=$(mktemp -d) echo DIR=${DIR} NAME=${0##*/} OUT=${DIR}/${NAME%%.sh}.out i=0 while [ ${i} -lt 512 ]; do echo ${i} >> ${DIR}/bar i=$((i+1)) done tail -b 1 ${DIR}/bar > ${OUT} tail -b -1 ${DIR}/bar > ${OUT}1 diff -u ${OUT} ${OUT}1 || exit 1 diff -u ${OUT} ${0%%.sh}.out || exit 1 # cleanup if okay rm -Rf ${DIR}