Passing flags to AC_CHECK_HEADER

[Chris Stankevitz]

Hello,

The following command assigns the variable OPENCV_CFLAGS with "-I
/path/to/opencv/include":
PKG_CHECK_MODULES(OPENCV, opencv >= 2.3.1,, AC_MSG_ERROR(${OPENCV_PKG_ERRORS}))

Q1: How to I tell AC_CHECK_HEADER to use the include directory
specified in OPENCV_CFLAGS?

A1: CPPFLAGS="${OPENCV_CFLAGS} $CPPFLAGS"

Q2: But I thought I wasn't supposed to mess with CPPFLAGS, it was only
for the user to play with.  Plus I don't want to affect all CPPFLAGS
for the entire project.  I intend to selectively apply OPENCV_CFLAGS
where needed.

A2: That's not a question.

Thank you,

Chris