Command
pg_dump -U username dbname > backup.sql
Explanation
Backs up a PostgreSQL database to a file using pg_dump.
Examples
Backup database to file
pg_dump -U postgres mydb > mydb_backup.sql
pg_dump -U username dbname > backup.sql
Backs up a PostgreSQL database to a file using pg_dump.
Backup database to file
pg_dump -U postgres mydb > mydb_backup.sql