This is the second step to extract databases to migrate from an OEM repository. This script uses the CSV file generated by the Cloud Migration Advisor tool called "oem_emcli_control.csv" which contains a list of migration candidates.
Combined with the scripts in this ZIP file it will connect to all databases selected to be migrated and collect a minimum set of information, stored in a CSV file which you must then schare with the Oracle employee again. Thisnew CSV output is uploaded agin into the Cloud Migration Advisor and is now used to classify the migration options.
So to get the the details from all possible databases you want to migrate, please follow these steps:
1. Unzip the files in a directory on a host with emcli installed
2. make sure the CSV file is located in the same directory.
3. add the emcli directory to the PATH variable
4. Also a requirement is to set up credentials to connect to the host and as sysdba to each database marked as migrate.
A note explaining how to do that is available on MOS: Emcli Execute_sql Fails With Error 'Preferred Credentials Do Not Exist For Some Targets" in Enterprise Manager 12c (Doc ID 1639266.1)

5. export environment variable EMCLI_HOME pointing to the directory where emcli is installed
6. After preparation the syntax to execute the collector is:
./cma_oem_emcli_control.sh <OMS username - e.g. sysman> <OEM SQL Credentials for OMS user>
e.g.:  ./cma_oem_emcli_control.sh sysman DBCredsNormal
