[SOLVED] How do I know the "default include directories", "default link directories" and "default link libraries" of gcc, g++/c++ in Ubuntu 11.04?

Issue

For the following 3 compile cases :

gcc -o helloc hello.c                    (1)

g++ -o hellocpp hello.cpp                (2)

c++ -o hellocpp hello.cpp                (3)

how do I know the "default include directories", "default link directories" and "default link libraries" in each case ? I am using gcc 4.5.2 in a 32 bit Ubuntu 11.04 environment.

For case (1), is gcc using the standard C libraries or the GNU C libraries ? Is there difference between the two C libraries ?

Comparing cases (2) and (3), is there any difference in the "default link libraries" used by the compiler ? Are they using the standard C++ libraries or the GNU C++ libraries ? What is the difference between the two C++ libraries ?

Thanks in advance for any suggestion.

Lawrence Tsang

Solution

Say gcc -v, or g++ -v to print out verbose information about the environment.

E.g. for me this says:

#include <...> search starts here:
 /usr/local/lib/gcc/i686-pc-linux-gnu/4.6.2/../../../../include/c++/4.6.2
 /usr/local/lib/gcc/i686-pc-linux-gnu/4.6.2/../../../../include/c++/4.6.2/i686-pc-linux-gnu
 /usr/local/lib/gcc/i686-pc-linux-gnu/4.6.2/../../../../include/c++/4.6.2/backward
 /usr/local/lib/gcc/i686-pc-linux-gnu/4.6.2/include
 /usr/local/include
 /usr/local/lib/gcc/i686-pc-linux-gnu/4.6.2/include-fixed
 /usr/include

Also try gcc -dumpspecs to see details about the invoked tools in the tool chain.

Answered By - Kerrek SB

Answer Checked By - David Goodson (WPSolving Volunteer)