Compile a PLSQL package code that was passed to an sqlplus session via a shell script?
Running XX_PKGb.sql (a package create statement) from with your PL/SQL block is not allowed. If you must do it there then it needs to be dynamic SQL. 

The better way is to simply run it from SQLPlus;

set term on

set echo off

set feedback off

set define on

set verify off

ALTER SESSION SET CURRENT_SCHEMA = XXEOM      
/
@XX_PKGb.sql
/
exit