1#!/bin/sh
2
3filename=${1:-sparse.dat}
4size=${2:-100M}
5
6echo "start" > $filename
7dd if=/dev/zero of=$filename bs=1 count=0 seek=$size 2>/dev/null
8echo "end" >> $filename
9
10size="`du --block-size=1 --apparent-size ${filename} | cut -f 1`"
11realsize="`du --block-size=1 ${filename} | cut -f 1`"
12
13printf "$filename created.\n"
14printf "size=%s\n" "$size"
15printf "realsize=%s\n" "$realsize"
16
17if [ "$realsize" -gt "$size" ]; then
18    printf "ERROR: realsize has to be smaller than size.\n"
19    exit 1
20fi
21