EM 13c: How to Recover the Inventory Records for the Enterprise Manager 13c Cloud Control OMS and Agent Oracle Homes if the Inventory is Lost or Corrupt (Doc ID 2105829.1)

Enterprise Manager Base Platform - Version 13.1.0.0.0 and later
Information in this document applies to any platform.

Goal

If the inventory is corrupt or lost, it is necessary to recover it to allow future patching actions. This document explains how this recovery or recreation can be accomplished.
See the full context of inventory management in the Universal Installer (OUI) User's Guide. While written for EM 12c, it also applies to EM 13c:
Universal Installer (OUI) User's Guide
Oracle Enterprise Manager Cloud Control Documentation, 12c Release 5 / Reference
Chapter 2 Managing Oracle Home Directories

Solution

For the 13c OMS:
Execute attachHome.sh in OMS_HOME/oui/bin
Example:

[oracle@newhire2 bin]$ cd /home/oracle/13c/middleware/oui/bin
[oracle@newhire2 bin]$ ./attachHome.sh
Launcher log file is /tmp/OraInstall2016-02-12_12-40-50AM/launcher2016-02-12_12-40-50AM.log.
Starting Oracle Universal Installer

Checking swap space: must be greater than 500 MB.   Actual 7959 MB    Passed
Checking if this platform requires a 64-bit JVM.   Actual 64    Passed (64-bit not required)


'attachHome' was successful.
Logs successfully copied to /u01/app/oraInventory/logs.

For 13c Agents:
Execute attachHome.sh in AGENT_HOME/oui/bin
Example:

[oracle@newhire2 bin]$ cd /home/oracle/13c/agent/agent_13.1.0.0.0/oui/bin
[oracle@newhire2 bin]$ ./attachHome.sh
Launcher log file is /tmp/OraInstall2016-02-12_12-43-09AM/launcher2016-02-12_12-43-09AM.log.
Starting Oracle Universal Installer

Checking swap space: must be greater than 500 MB.   Actual 7959 MB    Passed
Checking if this platform requires a 64-bit JVM.   Actual 64    Passed (64-bit not required)


'attachHome' was successful.
Logs successfully copied to /u01/app/oraInventory/logs.

Note:
In case a custom inventory is being used, pass the location of oraInst.loc file using -invPtrLoc parameter.
Example: ./attachHome.sh -invPtrLoc /u01/app/oraInst.loc