Read a model from a file.
A non-zero return value indicates that a problem occurred while reading the model. Refer to the Error Code table for a list of possible return values. Details on the error can be obtained by calling GRBgeterrormsg.
env: The environment in which to load the new model. This should come from a previous call to GRBloadenv.
filename: The path to the file to be read. Note that the type of the file is encoded in the file name suffix. Valid suffixes are .mps, .rew, .lp, .rlp, .ilp, or .opb. The files can be compressed, so additional suffixes of .zip, .gz, .bz2, or .7z are accepted.
modelP: The location in which the pointer to the model should be placed.
GRBmodel *model; error = GRBreadmodel(env, "/tmp/model.mps.bz2", &model);