6.6.9.4 -llibrary

Search the library named library when linking.

The linker searches a standard list of directories for the library, which is actually a file named liblibrary.a. The linker then uses this file as if it had been specified precisely by name.

It makes a difference where in the command you write this option; the linker processes libraries and object files in the order they are specified. Thus, foo.o -lz bar.o searches library z after file foo.o but before bar.o. If bar.o refers to functions in libz.a, those functions may not be loaded.

The directories searched include several standard system directories, plus any that you specify with -L.

Normally the files found this way are library files (archive files whose members are object files). The linker handles an archive file by scanning through it for members which define symbols that have so far been referenced but not defined. But if the file that is found is an ordinary object file, it is linked in the usual fashion. The only difference between using an -l option (e.g., -lmylib) and specifying a file name (e.g., libmylib.a) is that -l searches several directories, as specified.

By default the linker is directed to search:

<install-path>\lib

for libraries specified with the -l option.

This behavior can be overridden using the environment variables defined in 20.3 Predefined Macro Names.