finds all sqlite databases in the current folder (and subfolders) and executes sqlite3 $FILE "VACUUM;" on all databases

optimize-sqlite.sh

#!/bin/bash

find -type f \( -name "*.db" -or -name "*.sqlite" \) -print0 | while read -d $'\0' FILE
do
	TYPE=`file "$FILE" | grep -i sqlite`
	[ -z "$TYPE" ] && continue # this is not an sqlite db
	PRESIZE=`ls -sh "$FILE" | cut -f 1 -d " "`
	PRESIZEFULL=`ls -s "$FILE" | cut -f 1 -d " "`
	sqlite3 "$FILE" "VACUUM;"
	POSTSIZE=`ls -sh "$FILE" | cut -f 1 -d " "`
	POSTSIZEFULL=`ls -s "$FILE" | cut -f 1 -d " "`
	PERCENTAGE=`echo "$POSTSIZEFULL*100/$PRESIZEFULL" | bc`
	echo -e "$PERCENTAGE%:\t$PRESIZE\t→  $POSTSIZE\t: $FILE"
done