Partial implementation of Thomas Runge's BSD port.

configure.in

@@ -5,13 +5,28 @@ AM_CONFIG_HEADER(config.h)
 
 AC_CANONICAL_HOST
 case "$host" in
-*-*-*linux*) 
-	AC_DEFINE(LINUX)
+*-*-*linux*)      dnl i586-pc-linux-gnu
+	AC_DEFINE([LINUX],[1],[Define if you're using Linux.])
+	ac_system_host=Linux
 	;;
 *-*-*solaris*)
-	AC_DEFINE(SOLARIS)
+	AC_DEFINE([SOLARIS],[1],[Define if you're using Solaris.])
+	ac_system_host=Solaris
+	;;
+*-*-*openbsd*)    dnl i386-unknown-openbsd3.0
+	AC_DEFINE([OPENBSD],[1],[Define if you're using OpenBSD.])
+	ac_system_host=OpenBSD
+	;;
+*-*-*netbsd*)
+	AC_DEFINE([NETBSD],[1],[Define if you're using NetBSD.])
+	ac_system_host=NetBSD
+	;;
+*-*-*freebsd*)
+	AC_DEFINE([FREEBSD],[1],[Define if you're using FreeBSD.])
+	ac_system_host=FreeBSD
 	;;
 esac
+AC_DEFINE_UNQUOTED([SYSTEM_HOST], [$ac_system_host], [Set this to your system host (Linux, Solaris, OpenBSD, NetBSD or FreeBSD)])
 
 AC_MSG_CHECKING(whether to enable debugging)
 AC_ARG_ENABLE(debug,
@@ -44,7 +59,7 @@ AC_CHECK_FUNC(connect,,[AC_CHECK_LIB(socket,connect)])
 AC_CHECK_FUNC(inet_aton,,[AC_CHECK_LIB(resolv,inet_aton)])
 AC_CHECK_LIB(kstat, kstat_open)
 AC_CHECK_FUNCS(getloadavg swapctl)
-AC_CHECK_HEADERS(procfs.h sys/procfs.h sys/loadavg.h)
+AC_CHECK_HEADERS(procfs.h sys/procfs.h sys/loadavg.h utmpx.h)
 
 dnl Some versions of Solaris require -lelf for -lkvm
 AC_CHECK_LIB(kvm, kvm_open,[
@@ -66,7 +81,7 @@ AC_CHECK_LIB(kvm, kvm_open,[
 ])
 
 dnl NetBSD, OpenBSD and FreeBSD
-AC_CHECK_HEADERS(sched.h sys/types.h machine/pio.h machine/sysarch.h)
+AC_CHECK_HEADERS(sched.h sys/sched.h sys/types.h machine/pio.h machine/sysarch.h)
 AC_CHECK_LIB(i386, i386_get_ioperm)
 ETR_SYSV_IPC
 ETR_UNION_SEMUN
@@ -74,7 +89,8 @@ ETR_UNION_SEMUN
 dnl Checks for header files.
 AC_HEADER_DIRENT
 AC_HEADER_STDC
-AC_CHECK_HEADERS(fcntl.h sys/ioctl.h sys/time.h unistd.h sys/io.h)
+AC_CHECK_HEADERS(fcntl.h sys/ioctl.h sys/time.h unistd.h sys/io.h errno.h)
+AC_CHECK_HEADERS(limits.h kvm.h sys/param.h sys/sysctl.h sys/dkstat.h)
 
 dnl Check for particular preprocessor macros