Crontab

0 3 * * 0 /bin/du -m /data/ > /home/USER/du_files/"du_$(/bin/date +%Y%m%d)"

Script

cd ~/du_files

TODAYS_FILE="du_$(/usr/bin/date +%Y%m%d)"

YESTERDAYS_FILE="du_$(/usr/bin/date --date="7 days ago" +%Y%m%d)"

/usr/bin/echo "create table old (oldsize integer, path varchar);" > delta.sql

/usr/bin/echo "create table new (newsize integer, path varchar);" >> delta.sql

/usr/bin/echo '.separator "t" ' >> delta.sql

/usr/bin/echo ".import $TODAYS_FILE new" >> delta.sql

/usr/bin/echo ".import $YESTERDAYS_FILE old" >> delta.sql

/usr/bin/echo ".mode csv" >> delta.sql

/usr/bin/echo ".headers on" >> delta.sql

/usr/bin/echo ".out deltas.csv" >> delta.sql

/usr/bin/echo "select *,newsize-oldsize as delta_in_megabytes from old natural join new where oldsize<newsize order by delta_in_megabytes desc;" >> delta.sql

/usr/bin/sqlite3 < delta.sql

echo $YESTERDAYS_FILE|/usr/bin/mailx -a deltas.csv -s deltas.csv [email protected]

Resulting SQL

create table old (oldsize integer, path varchar);

create table new (newsize integer, path varchar);

.separator "t"

.import du_20160821 new

.import du_20160814 old

.mode csv

.headers on

.out deltas.csv

select *,newsize-oldsize as delta_in_megabytes

from old natural join new where oldsize<newsize

order by delta_in_megabytes desc;