What are the GCC default include directories?
In order to figure out the default paths used by gcc
/g++
, as well as their priorities, you need to examine the output of the following commands:
- For C:
gcc -xc -E -v -
- For C++:
gcc -xc++ -E -v -
The credit goes to Qt Creator team.
There is a command with a shorter output, which allows to automatically cut the include pathes from lines, starting with a single space:
$ echo | gcc -Wp,-v -x c++ - -fsyntax-only
ignoring nonexistent directory "/usr/lib/gcc/x86_64-redhat-linux/4.8.2/include-fixed"
ignoring nonexistent directory "/usr/lib/gcc/x86_64-redhat-linux/4.8.2/../../../../x86_64-redhat-linux/include"
#include "..." search starts here:
#include <...> search starts here:
/usr/lib/gcc/x86_64-redhat-linux/4.8.2/../../../../include/c++/4.8.2
/usr/lib/gcc/x86_64-redhat-linux/4.8.2/../../../../include/c++/4.8.2/x86_64-redhat-linux
/usr/lib/gcc/x86_64-redhat-linux/4.8.2/../../../../include/c++/4.8.2/backward
/usr/lib/gcc/x86_64-redhat-linux/4.8.2/include
/usr/local/include
/usr/include
End of search list.
The credit goes to the libc++ front-page.
To summarise the other answers:
For C++:
c++ -xc++ /dev/null -E -Wp,-v 2>&1 | sed -n 's,^ ,,p'
For C:
cc -xc /dev/null -E -Wp,-v 2>&1 | sed -n 's,^ ,,p'