Concatenate json files by date (which appears as part of the file name)

concatenate-by-filename.sh

#
# grouping files of 2014-04-12-01.json format into one json per mday (2014-04-12)
#
distinct_dates=$(ls -l | awk '{print $9}' | awk -F "-" '{count[$1"-"$2"-"$3]++}END{for(j in count) print j}')
for i in $distinct_dates
do
  echo "Grouping for $i month"
  cat $i-*.json* > /tmp/$i.json
done