* 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, 22 insertions, 0 deletions

diff --git a/configure b/configure
index fe27ace2..e318ef17 100755
--- a/configure
+++ b/configure
@@ -1281,6 +1281,8 @@ int x = sizeof ((struct tm *) 0)->$try_field;
   fi
 done
 
+printf "done\n"
+
 printf "Checking for POSIX sleep function ... "
 
 cat > conftest.c <<!
@@ -1301,6 +1303,26 @@ else
   have_unistd=y
 fi
 
+printf "Checking for BSD daemon function ... "
+
+cat > conftest.c <<!
+#include <unistd.h>
+
+int main(int argc, char **argv)
+{
+  daemon(0, 0);
+  return 0;
+}
+!
+rm -f conftest
+if ! $make conftest > conftest.err 2>&1 || ! [ -x conftest ] ; then
+  printf "no\n"
+else
+  printf "yes\n"
+  printf "#define HAVE_DAEMON 1\n" >> config.h
+  have_unistd=y
+fi
+
 #
 # Dependent variables
 #