Microsoft linkers usually use the LIB environment variable to specify alternate search locations for libraries. To avoid conflicts with Windows utilities, the Interix cc(1) and c89(1) utilities ignore the initial value of LIB. You can add additional libraries to the search path by using the -L option, which you can specify multiple times on the command line.
You can also specify libraries with the traditional operands -lc, -ll, -lm, and -ly. These specify the C library, the lex library, the math library and the yacc library, respectively.
Many compilers make use of the INCLUDE environment variable to specify alternate search locations for header files. To avoid conflict with Windows utilities, the c89 utility ignores the initial value of INCLUDE. You can add additional directories to the search path with the -I option, which you can specify multiple times on the command line.