--- lbbs/configure.ac	2025/11/18 03:19:20	1.62
+++ lbbs/configure.ac	2025/11/20 09:02:46	1.63
@@ -19,6 +19,15 @@ AC_PROG_INSTALL
 AC_PROG_LN_S
 AC_PROG_MAKE_SET
 
+AC_ARG_WITH([sysv],
+            [AS_HELP_STRING([--with-sysv], [Use System V specific APIs])],
+            [AS_IF([test "x$with_sysv" = xyes],
+                   [AC_DEFINE([HAVE_SYSTEM_V], [1], [Define if System V is available])])])
+AC_ARG_ENABLE([debug],
+              [AS_HELP_STRING([--enable-debug], [Enable debug log])],
+              [AS_IF([test "x$enable_debug" = xyes],
+                     [AC_DEFINE([_DEBUG], [1], [Define if debug log is enabled])])])
+
 AC_ARG_WITH([iconv],
             [AS_HELP_STRING([--with-iconv], [Use iconv library package config])],
             [],
@@ -59,9 +68,9 @@ AC_PROG_EGREP
 
 AC_HEADER_RESOLV
 AC_HEADER_SYS_WAIT
-AC_CHECK_HEADERS([arpa/inet.h fcntl.h iconv.h libssh/libssh.h mysql.h netdb.h netinet/in.h pcre2.h \
-                  pty.h signal.h stdint.h stdlib.h string.h sys/ioctl.h sys/ipc.h sys/mman.h sys/param.h sys/socket.h \
-                  sys/types.h sys/sem.h sys/shm.h sys/stat.h sys/wait.h time.h unistd.h utmp.h wchar.h],
+AC_CHECK_HEADERS([arpa/inet.h fcntl.h iconv.h libssh/libssh.h mysql.h netdb.h netinet/in.h pcre2.h pty.h \
+                  semaphore.h signal.h stdint.h stdlib.h string.h sys/ioctl.h sys/mman.h sys/param.h sys/socket.h \
+                  sys/types.h sys/sem.h sys/stat.h sys/wait.h time.h unistd.h utmp.h wchar.h],
                   [],
                   [AC_MSG_ERROR([Missing required header file])],
                   [#define PCRE2_CODE_UNIT_WIDTH 8])
@@ -101,9 +110,4 @@ AC_CONFIG_FILES([Makefile
                  conf/lbbs.service
                  conf/lbbs.logrotate])
 
-AC_ARG_ENABLE([debug],
-              [AS_HELP_STRING([--enable-debug], [Enable debug log])],
-              [AS_IF([test "x$enable_debug" = xyes],
-                     [AC_DEFINE([_DEBUG], [1], [Define if debug log is enabled])])])
-
 AC_OUTPUT