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(autoconf.info)Generic Structures

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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],
          [ACTION-IF-NOT-FOUND], [INCLUDES = `default-includes'])
     Check whether MEMBER is a member of the aggregate AGGREGATE.  If
     no INCLUDES are specified, the default includes are used (Note:
     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 sub-members:

          AC_CHECK_MEMBER(struct top.middle.bot)

 - Macro: AC_CHECK_MEMBERS (MEMBERS, [ACTION-IF-FOUND],
          [ACTION-IF-NOT-FOUND], [INCLUDES = `default-includes'])
     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).

     This macro uses m4 lists:
          AC_CHECK_MEMBERS([struct stat.st_rdev, struct stat.st_blksize])