dnl ---------------
dnl CHECK FUNCTIONS
dnl ---------------
-AC_CHECK_FUNCS(writev lstat tzset getutent nl_langinfo)
+AC_CHECK_FUNCS(writev lstat tzset getutent nl_langinfo sigaction sigprocmask \
+ sigblock sigsetmask sighold sigrelse)
dnl Look for the initgroups() declaration. On AIX 4.[13], Solaris 4.1.3, and
dnl ULTRIX 4.2A the function is defined in libc but there's no declaration in