SlackBuildsOrg/development/sqlcl

Oracle SQL Developer Command Line

Oracle SQL Developer Command Line (SQLcl) is a free command line
interface for Oracle Database. It allows you to interactively or batch
execute SQL and PL/SQL. SQLcl provides in-line editing, statement
completion, and command recall for a feature-rich experience,  all
while also supporting your previously written SQL*Plus scripts.

You need an Oracle account and you must Agree to Oracle's download
agreement before this can be downloaded.
You have to use a web browser to download it.