usage()

{

    cat <<EOF

Usage: libpng-config [OPTION] ...

Known values for OPTION are:

  --prefix        print libpng prefix

  --libdir        print path to directory containing library

  --libs          print library linking information

  --ccopts        print compiler options

  --cppflags      print pre-processor flags

  --cflags        print preprocessor flags, I_opts, and compiler options

  --I_opts        print "-I" include options

  --L_opts        print linker "-L" flags for dynamic linking

  --R_opts        print dynamic linker "-R" or "-rpath" flags

  --ldopts        print linker options

  --ldflags       print linker flags (ldopts, L_opts, R_opts, and libs)

  --static        revise subsequent outputs for static linking

  --help          print this help and exit

  --version       print version information

EOF

    exit $1

}

if test $# -eq 0; then

    usage 1

fi

while test $# -gt 0; do

    case "$1" in

    --prefix)

        echo ${prefix}

        ;;

    --version)

        echo ${version}

        exit 0

        ;;

    --help)

        usage 0

        ;;

    --ccopts)

        echo ${ccopts}

        ;;

    --cppflags)

        echo ${cppflags}

        ;;

    --cflags)

        echo ${I_opts} ${cppflags} ${ccopts}

        ;;

    --libdir)

        echo ${libdir}

        ;;

    --libs)

        echo ${libs}

        ;;

    --I_opts)

        echo ${I_opts}

        ;;

    --L_opts)

        echo ${L_opts}

        ;;

    --R_opts)

        echo ${R_opts}

        ;;

    --ldflags)

        echo ${ldflags} ${L_opts} ${R_opts} ${libs}

        ;;

    --static)

        R_opts=""

        ;;

    *)

        usage

        exit 1

        ;;

    esac

    shift

done

exit 0