Data flow
When the engine/monitorD/tool starts, the configuration file with defined global variables is loaded into the engine/monitorD/tool.
When there are other configuration files, it replaces the global variables in each configuration file loading a process.
With the NetConfig file, it replaces the global variable when it gets the value or replaces all variables before paring it as a Tcl object.
For xlate files, it does the global variable replacement in the xlate file compiling period.
The configuration file loader in the engine/monitorD/tool replaces the global variable with the defined real value in the global variable definition file. Encrypted values in the global variable file are first decrypted and then used for replacement by the loader.
If the engine/monitorD/tool fails to do the replacement, then a warning is issued in the log.