5.8.2 Generic Structure Checks

These macros are used to find structure members not covered by the “particular” test macros.

Macro: AC_CHECK_MEMBER (aggregate.member,   [action-if-found]@c, [action-if-not-found]@c,   [includes = ‘AC_INCLUDES_DEFAULT’]@c)

Check whether member is a member of the aggregate aggregate. If no includes are specified, the default includes are used (see section Default Includes).

AC_CHECK_MEMBER([struct passwd.pw_gecos], [], [AC_MSG_ERROR([We need `passwd.pw_gecos'!])], [[#include <pwd.h>]])

You can use this macro for submembers:

AC_CHECK_MEMBER(struct top.middle.bot)

Macro: AC_CHECK_MEMBERS (members, [action-if-found]@c,   [action-if-not-found]@c, [includes = ‘AC_INCLUDES_DEFAULT’]@c)

Check for the existence of each ‘aggregate.member’ of members using the previous macro. When member belongs to aggregate, define HAVE_aggregate_member (in all capitals, with spaces and dots replaced by underscores). If action-if-found is given, it is executed for each of the found members. If action-if-not-found is given, it is executed for each of the members that could not be found.

includes is a series of include directives, defaulting to AC_INCLUDES_DEFAULT (see section Default Includes), which are used prior to the members under test.

This macro uses M4 lists:

AC_CHECK_MEMBERS([struct stat.st_rdev, struct stat.st_blksize])