The search for include files is governed by two environment variables: GENPATH: #include "File" Path and LIBRARYPATH: `include <File>' Path. Include files are included using double quotes or angle brackets.
When you use double quotes to include files ( #include "test.h"), the compiler searches first in the current directory, then in the directory specified by the -I option (refer -I: Include File Path), then in the directories given in the GENPATH environment variable (refer GENPATH: #include "File" Path), and finally in those listed in the LIBPATH or LIBRARYPATH: ` include <File>' Path environment variable. Set the current directory using the IDE, the Program Manager, or the DEFAULTDIR environment variable (refer DEFAULTDIR: Default Current Directory).
When you use angle brackets to include files ( #include <stdio.h>), the compiler searches first in the current directory, then in the directory specified by the -I option, and then in the directories given in LIBPATH or LIBRARYPATH. Set the current directory using the IDE, the Program Manager, or the DEFAULTDIR environment variable.