GNU project C and C++ compiler
-pthread
    Adds support for multithreading with the pthreads library.  This option sets flags for both the
    preprocessor and linker.
-o file
    Place output in file file.  This applies regardless to whatever sort of output is being produced,
    whether it be an executable file, an object file, an assembler file or preprocessed C code.

    If -o is not specified, the default is to put an executable file in a.out, the object file for
    source.suffix in source.o, its assembler file in source.s, a precompiled header file in
    source.suffix.gch, and all preprocessed C source on standard output.
-llibrary
-l library
    Search the library named library when linking.  (The second alternative with the library as a
    separate argument is only for POSIX compliance and is not recommended.)

    It makes a difference where in the command you write this option; the linker searches and 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 z, those functions may not be
    loaded.

    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.

    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 and specifying a file
    name is that -l surrounds library with lib and .a and searches several directories.
-c  Compile or assemble the source files, but do not link.  The linking stage simply is not done.  The
    ultimate output is in the form of an object file for each source file.

    By default, the object file name for a source file is made by replacing the suffix .c, .i, .s, etc.,
    with .o.

    Unrecognized input files, not requiring compilation or assembly, are ignored.
-p  Generate extra code to write profile information suitable for the analysis program prof.  You must
    use this option when compiling the source files you want data about, and you must also use it when
    linking.

-pg Generate extra code to write profile information suitable for the analysis program gprof.  You must
    use this option when compiling the source files you want data about, and you must also use it when
    linking.
source manpages: g++-4.6