Stupid question...

["Robert G. Brown" <rgb@phy.duke.edu>]

I'm trying to get gsl to be correctly detected in a configure.ac
(something that has never quite worked, for reasons I don't understand).

The following lines are what I've got.  I don't quite understand either
why the gsl check fails or why the gslcblas succeeds.  I've tried lots
of different functions (including [main]) in the gsl check, but they all
return no.  I've tried including an argument such as gsl_sf_gamma(1.0),
no go.  Is there a simple one liner solution to this somebody could
contribute, or is somebody enough of an expert with autoconf that they
can tell me why this works/doesn't work?

#==================================================================
# Checks for libraries, and headers.
#==================================================================
AC_CHECK_HEADER([gsl/gsl_sf_gamma.h],,[AC_MSG_ERROR([Couldn't find GSL headers! Please install gsl-devel.])])
AC_CHECK_LIB([gsl],[gsl_sf_gamma])
# FIXME: Replace `main' with a function in `-lgslcblas':
AC_CHECK_LIB([gslcblas], [main])


checking gsl/gsl_sf_gamma.h usability... yes
checking gsl/gsl_sf_gamma.h presence... yes
checking for gsl/gsl_sf_gamma.h... yes
checking for gsl_sf_gamma in -lgsl... no
checking for main in -lgslcblas... yes


TIA,

    rgb

Robert G. Brown	                       http://www.phy.duke.edu/~rgb/
Duke University Dept. of Physics, Box 90305
Durham, N.C. 27708-0305
Phone: 1-919-660-2567  Fax: 919-660-2525     email:rgb@phy.duke.edu