- AC_REQUIRE(AC_HEADER_STDC)
- test -z "$ac_cv_header_memory_h" && AC_CHECK_HEADERS(memory.h)
- test -z "$ac_cv_header_string_h" && AC_CHECK_HEADERS(string.h)
- test -z "$ac_cv_header_strings_h" && AC_CHECK_HEADERS(strings.h)
- test -z "$ac_cv_header_unistd_h" && AC_CHECK_HEADERS(unistd.h)