This should work:
# To export to file (data only)
mysqldump -u [user] -p[pass] --no-create-info mydb > mydb.sql
# To export to file (structure only)
mysqldump -u [user] -p[pass] --no-data mydb > mydb.sql
# To import to database
mysql -u [user] -p[pass] mydb < mydb.sql
NOTE: there's no space between -p
& [pass]