You can either:

• Provide the path to one or more SQL files as command line arguments:

  $ sqlfmt testdata/select_where.input.sql
  select
    foo,
    bar
  from
    baz
  where
    foo > 5
    and bar < 2

• Or, directly provide the SQL string via stdin:

  $ echo "select * from users" | sqlfmt
  select
    *
  from
    users

  $ sqlfmt < testdata/like.input.sql
  select
    foo,
    bar
  from
    baz
  where
    foo like 'abd%'
    or foo like 'ada%' escape '!'
    or foo not like 'abd%'
    or foo not like 'ada%' escape '!'
    or foo ilike 'efg%'
    or foo ilike 'ada%' escape '!'
    or foo not ilike 'efg%'
    or foo not ilike 'ada%' escape '!'

View testdata for more examples.