AC_REPLACE_FUNCS(snprintf strerror strdup)
-dnl Look for the initgroups() declaration. On AIX 4.[13] and Solaris 4.1.3,
-dnl the function is defined in libc but there's no declaration in any system
-dnl header.
+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
+dnl any system header.
dnl
dnl On Solaris 2.[456], the declaration is in <grp.h>. On HP-UX 9-11 and
dnl (reportedly) FreeBSD 3.[23], it's in <unistd.h>. Any other locations we