|const char||*logfilename )|
Create an environment. Optimization models live within an environment, so this is typically the first Gurobi routine called in an application.
This routine will also populate any parameter (ComputeServer, TokenServer, ServerPassword, etc.) specified in your gurobi.lic file. This routine will also check the current working directory for a file named gurobi.env, and it will attempt to read parameter settings from this file if it exists. The file should be in PRM format (briefly, each line should contain a parameter name, followed by the desired value for that parameter).
In general, you should aim to create a single Gurobi environment in your program, even if you plan to work with multiple models. Reusing one environment is much more efficient than creating and destroying multiple environments. The one exception is if you are writing a multi-threaded program, since environments are not thread safe. In this case, you will need a separate environment for each of your threads.
A non-zero return value indicates that there was a problem creating the environment. Refer to the Error Code table for a list of possible return values.
envP: The location in which the pointer to the newly created environment should be placed.
logfilename: The name of the log file for this environment. May be NULL (or an empty string), in which case no log file is created.