1 dnl ac_var_timeszone_externals.m4

     2 

     3 # Define 'timezone', 'altzone' and 'daylight'

     4 # http://www.gnu.org/software/ac-archive/Miscellaneous/ac_var_timezone_externals.html

     5 # Use instead of 'AC_STRUCT_TIMEZONE' to determine whether the

     6 # the external timezone variables 'timezone', 'altzone' and 'daylight' exist,

     7 # defining 'HAVE_TIMEZONE', 'HAVE_ALTZONE' and 'HAVE_DAYLIGHT' respectively

     8 # (as well as gaining the macros defined by 'AC_STRUCT_TIMEZONE').

     9 # Mark R.Bannister <markb@freedomware.co.uk>

    10 AC_DEFUN([AC_VAR_TIMEZONE_EXTERNALS],

    11 [  AC_REQUIRE([AC_STRUCT_TIMEZONE])dnl

    12    AC_CACHE_CHECK(for timezone external, mb_cv_var_timezone,

    13    [  AC_TRY_LINK([#include <time.h>], [return (int)timezone;],

    14          mb_cv_var_timezone=yes,

    15          mb_cv_var_timezone=no)

    16    ])

    17    AC_CACHE_CHECK(for altzone external, mb_cv_var_altzone,

    18    [  AC_TRY_LINK([#include <time.h>], [return (int)altzone;],

    19          mb_cv_var_altzone=yes,

    20          mb_cv_var_altzone=no)

    21    ])

    22    AC_CACHE_CHECK(for daylight external, mb_cv_var_daylight,

    23    [  AC_TRY_LINK([#include <time.h>], [return (int)daylight;],

    24          mb_cv_var_daylight=yes,

    25          mb_cv_var_daylight=no)

    26    ])

    27    if test $mb_cv_var_timezone = yes; then

    28       AC_DEFINE([HAVE_TIMEZONE], 1,

    29               [Define if you have the external 'timezone' variable.])

    30    fi

    31    if test $mb_cv_var_altzone = yes; then

    32       AC_DEFINE([HAVE_ALTZONE], 1,

    33               [Define if you have the external 'altzone' variable.])

    34    fi

    35    if test $mb_cv_var_daylight = yes; then

    36       AC_DEFINE([HAVE_DAYLIGHT], 1,

    37               [Define if you have the external 'daylight' variable.])

    38    fi

    39 ])