Oracle's dbms_metadata.get_ddl for object_type JOB
select dbms_metadata.get_ddl('PROCOBJ', 'yourJobNameGoesHere') from dual;
PROCOBJ's are procedural objects.
select dbms_metadata.get_ddl('PROCOBJ',['JOB'|'PROGRAM'|'SCHEDULE'],'OWNER') from dual;
The PROCOBJ
can be JOB, PROGRAM and SCHEDULE.
Alternative, get all jobs from the database with their DDL:
select owner, job_name, dbms_metadata.get_ddl('PROCOBJ', job_name, owner) as ddl_output from ALL_SCHEDULER_JOBS