Add more apis to redbean unix module

- Document unix.fcntl()
- Add POSIX Advisory Locks
- Add mask parameter to unix.poll()
- Add lowest parameter to unix.dup()

third_party/make/config.h

@@ -507,21 +507,11 @@
 #define MAKE_HOST "x86_64-cosmopolitan"
 
 /* Define to 1 to enable job server support in GNU make. */
-/*
- * TODO(jart): Why does job server not work? We don't need it, since the
- *             last thing we'd ever want is a recursive make, however it
- *             would be nice to confirm it's not a bug in our libc impl.
- */
-/* #define MAKE_JOBSERVER 1 */
+#define MAKE_JOBSERVER 1
 
 /* Define to 1 to enable symbolic link timestamp checking. */
 #define MAKE_SYMLINKS 1
 
-/* Use GNU style printf and scanf.  */
-#ifndef __USE_MINGW_ANSI_STDIO
-#define __USE_MINGW_ANSI_STDIO 1
-#endif
-
 /* Define to 1 if the nlist n_name member is a pointer */
 /* #undef N_NAME_POINTER */
 

third_party/make/posixos.c

@@ -16,6 +16,7 @@ this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
 #include "third_party/make/makeint.inc"
 /**/
+#include "libc/sock/select.h"
 #include "libc/sysv/consts/f.h"
 #include "libc/sysv/consts/fd.h"
 #include "libc/sysv/consts/sa.h"
@@ -231,18 +232,16 @@ unsigned int jobserver_acquire(int timeout) {
     FD_SET(job_fds[0], &readfds);
 
     r = pselect(job_fds[0] + 1, &readfds, NULL, NULL, specp, &empty);
-    if (r < 0) switch (errno) {
-        case EINTR:
+    if (r < 0)
+      {
+        if (errno == EINTR)
           /* SIGCHLD will show up as an EINTR.  */
           return 0;
-
-        case EBADF:
+        if (errno == EBADF)
           /* Someone closed the jobs pipe.
              That shouldn't happen but if it does we're done.  */
           O(fatal, NILF, _("job server shut down"));
-
-        default:
-          pfatal_with_name(_("pselect jobs pipe"));
+        pfatal_with_name(_("pselect jobs pipe"));
       }
 
     if (r == 0) /* Timeout.  */