Introducing LDAPCON Helper feature for LDAP (for thin), in Jan30 release:

Either
1/By environmental variable, or
2/sdsql /nolog
then
set LDAPCON jdbc:oracle:thin:@ldap://ldapmachine.us.oracle.com:389/#ENTRY#,cn=OracleContext,dc=ie,dc=lcom
(the above is one line from set to lcom)

For example by bash environmental variable:
>set LDAPCON=jdbc:oracle:thin:@ldap://ldapmachine.us.oracle.com:389/#ENTRY#,cn=OracleContext,dc=ie,dc=lcom
(the above is one line from set to lcom)

>sdsql "sys/__the_password__@THEADDRESS" as sysdba
connects via: jdbc:oracle:thin:@ldap://ldapmachine.us.oracle.com:389/THEADDRESS,cn=OracleContext,dc=ie,dc=lcom

ldap.ora for sqlplus will contain:
Machine:ldapmachine.us.oracle.com port:389
and
context:cn=OracleContext,dc=ie,dc=lcom

I have not automated the removal of this information from ldap.ora

LDAP for thick:
As sqlplus configure via ldap.ora and sqlnet.ora

Note the file to kick off the command line product has been through a few iterations, seems to be currently sql (or sql.bat)