* configure: Detect the daemon function.

* eval.c: Include <unistd.h> conditionally.
(errno_wrap, daemon_wrap): New functions.
(eval_init): Registered errno_wrap and daemon_wrap as intrinsics
under the names daemon and errno.

* txr.1: Documented errno and daemon in new UNIX PROGRAMMING
section.

1 files changed, 20 insertions, 0 deletions

diff --git a/eval.c b/eval.c
index 395e9abe..4886856c 100644
--- a/eval.c
+++ b/eval.c
@@ -33,6 +33,9 @@
 #include <stdarg.h>
 #include <wchar.h>
 #include "config.h"
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
 #include "lib.h"
 #include "gc.h"
 #include "unwind.h"
@@ -2054,6 +2057,20 @@ static val force(val promise)
   return rplacd(promise, funcall(cdr(promise)));
 }
 
+static val errno_wrap(val newval)
+{
+  val oldval = num(errno);
+  if (newval)
+    errno = c_num(newval);
+  return oldval;
+}
+
+static val daemon_wrap(val nochdir, val noclose)
+{
+  int result = daemon(nochdir ? 1 : 0, noclose ? 1 : 0);
+  return result == 0 ? t : nil;
+}
+
 static void reg_fun(val sym, val fun)
 {
   sethash(top_fb, sym, cons(sym, fun));
@@ -2532,6 +2549,9 @@ void eval_init(void)
   reg_fun(intern(lit("time-string-utc"), user_package), func_n2(time_string_utc));
   reg_fun(intern(lit("make-time"), user_package), func_n7(make_time));
 
+  reg_fun(intern(lit("errno"), user_package), func_n1o(errno_wrap, 0));
+  reg_fun(intern(lit("daemon"), user_package), func_n2(daemon_wrap));
+
   reg_fun(intern(lit("source-loc"), user_package), func_n1(source_loc));
   reg_fun(intern(lit("source-loc-str"), user_package), func_n1(source_loc_str));