How to override environment variables when running configure?

include environment-variables autotools configure
Sam picture Sam · Apr 27, 2010 · Viewed 17.6k times · Source

In any major package for Linux, running ./configure --help will output at the end:

Some influential environment variables:
      CC          C compiler command
      CFLAGS      C compiler flags
      LDFLAGS     linker flags, e.g. -L<lib dir> if you have libraries in a
                  nonstandard directory <lib dir>
      CPPFLAGS    C/C++ preprocessor flags, e.g. -I<include dir> if you have
                  headers in a nonstandard directory <include dir>
      CPP         C preprocessor

Use these variables to override the choices made by `configure' or to help
it to find libraries and programs with nonstandard names/locations.

How do I use these variables to include a directory? I tried running ./configure --CFLAGS="-I/home/package/custom/" and ./configure CFLAGS="-I/home/package/custom/", however these do not work. Any suggestions?

Answer

ptomato picture ptomato · Apr 27, 2010

The variable you need to use for -I is CPPFLAGS, not CFLAGS. (As it says right there in the help message you copied.) CPP stands for "C preprocessor", not C++. So:

./configure CPPFLAGS='-I/home/package/custom'

Related questions

How to add a default include path for GCC in Linux?

I'd like gcc to include files from $HOME/include in addition to the usual include directories, but there doesn't seem to be an analogue to $LD_LIBRARY_PATH. I know I can just add the include directory at command line …

Read More
How to set include path in xcode project

I am trying to use a C library in an Objective-C Xcode project. The libraries directory structure is as follows: -- include/ |-- config.h |-- lib/ | |-- file1.h | |-- file2.h | |-- file3.h The library's docs say …

Read More
How do I include a JavaScript file in another JavaScript file?

Is there something in JavaScript similar to @import in CSS that allows you to include a JavaScript file inside another JavaScript file?

Read More