From 3a1f887928405cbec690424177700b8346e1eb74 Mon Sep 17 00:00:00 2001
From: Justine Tunney <jtunney@gmail.com>
Date: Wed, 11 Oct 2023 20:26:28 -0700
Subject: [PATCH] Introduce posix_spawn_file_actions_addchdir_np()

---
 examples/examples.mk                          |   2 +
 examples/greenbean.c                          | 319 ++++++-----
 examples/greenbean2.c                         | 515 ------------------
 libc/calls/mkntpath.c                         |  57 +-
 libc/calls/mkntpathat.c                       |  39 +-
 libc/calls/ntspawn.c                          |   7 +-
 libc/calls/pledge.c                           |   7 +-
 libc/calls/syscall_support-nt.internal.h      |   2 +
 libc/intrin/createprocess.c                   |   2 +-
 libc/intrin/ulock.c                           |   8 +-
 libc/isystem/cosmo.h                          |   2 +
 libc/proc/execve-nt.greg.c                    |   7 +-
 libc/proc/fork-nt.c                           |   3 +-
 libc/proc/ntspawn.h                           |   4 +-
 libc/proc/posix_spawn.c                       |  90 ++-
 libc/proc/posix_spawn.h                       |   3 +
 libc/proc/posix_spawn.internal.h              |   8 +-
 .../posix_spawn_file_actions_addchdir_np.c    |  41 ++
 .../posix_spawn_file_actions_addfchdir_np.c   |  39 ++
 libc/proc/posix_spawn_file_actions_addopen.c  |   4 +-
 libc/thread/pthread_setname_np.c              |   2 +-
 net/http/parsehttpmessage.c                   |   2 +-
 test/libc/calls/pledge_test.c                 |   6 +
 test/libc/proc/posix_spawn_test.c             |  24 +
 test/libc/proc/test.mk                        |   1 +
 25 files changed, 446 insertions(+), 748 deletions(-)
 delete mode 100644 examples/greenbean2.c
 create mode 100644 libc/proc/posix_spawn_file_actions_addchdir_np.c
 create mode 100644 libc/proc/posix_spawn_file_actions_addfchdir_np.c

diff --git a/examples/examples.mk b/examples/examples.mk
index 9c30c18a3..84e477f42 100644
--- a/examples/examples.mk
+++ b/examples/examples.mk
@@ -97,6 +97,8 @@ EXAMPLES_DIRECTDEPS =								\
 EXAMPLES_DEPS :=								\
 	$(call uniq,$(foreach x,$(EXAMPLES_DIRECTDEPS),$($(x))))
 
+$(EXAMPLES_OBJS): override CFLAGS += -isystem libc/isystem
+
 o/$(MODE)/examples/examples.pkg:						\
 		$(EXAMPLES_OBJS)						\
 		$(foreach x,$(EXAMPLES_DIRECTDEPS),$($(x)_A).pkg)
diff --git a/examples/greenbean.c b/examples/greenbean.c
index 40c51476d..9ab1dc093 100644
--- a/examples/greenbean.c
+++ b/examples/greenbean.c
@@ -7,6 +7,22 @@
 │   • http://creativecommons.org/publicdomain/zero/1.0/            │
 ╚─────────────────────────────────────────────────────────────────*/
 #endif
+#ifdef __COSMOCC__
+#define _COSMO_SOURCE
+#include <assert.h>
+#include <cosmo.h>
+#include <errno.h>
+#include <netinet/in.h>
+#include <netinet/tcp.h>
+#include <pthread.h>
+#include <signal.h>
+#include <stdatomic.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/auxv.h>
+#include <sys/socket.h>
+#include <time.h>
+#else
 #include "libc/assert.h"
 #include "libc/atomic.h"
 #include "libc/calls/calls.h"
@@ -20,65 +36,42 @@
 #include "libc/fmt/itoa.h"
 #include "libc/intrin/kprintf.h"
 #include "libc/log/log.h"
-#include "libc/mem/gc.internal.h"
+#include "libc/macros.internal.h"
+#include "libc/mem/gc.h"
 #include "libc/mem/mem.h"
 #include "libc/runtime/runtime.h"
 #include "libc/sock/sock.h"
 #include "libc/sock/struct/sockaddr.h"
+#include "libc/stdio/stdio.h"
 #include "libc/str/str.h"
 #include "libc/sysv/consts/af.h"
 #include "libc/sysv/consts/auxv.h"
+#include "libc/sysv/consts/clock.h"
+#include "libc/sysv/consts/limits.h"
 #include "libc/sysv/consts/sig.h"
 #include "libc/sysv/consts/so.h"
 #include "libc/sysv/consts/sock.h"
 #include "libc/sysv/consts/sol.h"
 #include "libc/sysv/consts/tcp.h"
+#include "libc/sysv/consts/timer.h"
 #include "libc/thread/thread.h"
 #include "libc/thread/thread2.h"
 #include "net/http/http.h"
+#endif
 
 /**
- * @fileoverview greenbean lightweight threaded web server
- *
- *     $ make -j8 o//tool/net/greenbean.com
- *     $ o//tool/net/greenbean.com &
- *     $ printf 'GET /\n\n' | nc 127.0.0.1 8080
- *     HTTP/1.1 200 OK
- *     Server: greenbean/1.o
- *     Referrer-Policy: origin
- *     Cache-Control: private; max-age=0
- *     Content-Type: text/html; charset=utf-8
- *     Date: Sat, 14 May 2022 14:13:07 GMT
- *     Content-Length: 118
- *
- *     <!doctype html>
- *     <title>hello world</title>
- *     <h1>hello world</h1>
- *     <p>this is a fun webpage
- *     <p>hosted by greenbean
- *
- * Like redbean, greenbean has superior performance too, with an
- * advantage on benchmarks biased towards high connection counts
- *
- *     $ wrk -c 300 -t 32 --latency http://127.0.0.1:8080/
- *     Running 10s test @ http://127.0.0.1:8080/
- *       32 threads and 300 connections
- *         Thread Stats   Avg      Stdev     Max   +/- Stdev
- *         Latency   661.06us    5.11ms  96.22ms   98.85%
- *         Req/Sec    42.38k     8.90k   90.47k    84.65%
- *       Latency Distribution
- *          50%  184.00us
- *          75%  201.00us
- *          90%  224.00us
- *          99%   11.99ms
- *       10221978 requests in 7.60s, 3.02GB read
- *     Requests/sec: 1345015.69
- *     Transfer/sec:    406.62MB
+ * @fileoverview greenbean lightweight threaded web server no. 2
  *
+ * This web server is the same as greenbean.c except it supports having
+ * more than one thread on Windows. To do that we have to make the code
+ * more complicated by not using SO_REUSEPORT. The approach we take, is
+ * creating a single listener thread which adds accepted sockets into a
+ * queue that worker threads consume. This way, if you like Windows you
+ * can easily have a web server with 10,000+ connections.
  */
 
 #define PORT      8080
-#define KEEPALIVE 30000
+#define KEEPALIVE 5000
 #define LOGGING   1
 
 #define STANDARD_RESPONSE_HEADERS \
@@ -86,21 +79,30 @@
   "Referrer-Policy: origin\r\n"   \
   "Cache-Control: private; max-age=0\r\n"
 
-int threads;
-int alwaysclose;
+int server;
 atomic_int a_termsig;
 atomic_int a_workers;
 atomic_int a_messages;
-atomic_int a_listening;
 atomic_int a_connections;
 pthread_cond_t statuscond;
 pthread_mutex_t statuslock;
 const char *volatile status = "";
 
+#if LOGGING
+// prints persistent status line
+//   \r moves cursor back to beginning of line
+// \e[K clears text from cursor to end of line
+#define LOG(FMT, ...) kprintf("\r\e[K" FMT "\n", ##__VA_ARGS__)
+#else
+#define LOG(FMT, ...) (void)0
+#endif
+
+// updates the status line if it's convenient to do so
 void SomethingHappened(void) {
   unassert(!pthread_cond_signal(&statuscond));
 }
 
+// performs a guaranteed update of the main thread status line
 void SomethingImportantHappened(void) {
   unassert(!pthread_mutex_lock(&statuslock));
   unassert(!pthread_cond_signal(&statuscond));
@@ -108,105 +110,96 @@ void SomethingImportantHappened(void) {
 }
 
 void *Worker(void *id) {
-  int server, yes = 1;
-
-  // load balance incoming connections for port 8080 across all threads
-  // hangup on any browser clients that lag for more than a few seconds
-  struct timeval timeo = {KEEPALIVE / 1000, KEEPALIVE % 1000};
-  struct sockaddr_in addr = {.sin_family = AF_INET, .sin_port = htons(PORT)};
-
-  server = socket(AF_INET, SOCK_STREAM, 0);
-  if (server == -1) {
-    kprintf("\r\e[Ksocket() failed %m\n");
-    if (errno == ENFILE || errno == EMFILE) {
-    TooManyFileDescriptors:
-      kprintf("sudo prlimit --pid=$$ --nofile=%d\n", threads * 3);
-    }
-    goto WorkerFinished;
-  }
-
-  // we don't bother checking for errors here since OS support for the
-  // advanced features tends to be a bit spotty and harmless to ignore
-  setsockopt(server, SOL_SOCKET, SO_RCVTIMEO, &timeo, sizeof(timeo));
-  setsockopt(server, SOL_SOCKET, SO_SNDTIMEO, &timeo, sizeof(timeo));
-  setsockopt(server, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes));
-  setsockopt(server, SOL_SOCKET, SO_REUSEPORT, &yes, sizeof(yes));
-  setsockopt(server, SOL_TCP, TCP_FASTOPEN, &yes, sizeof(yes));
-  setsockopt(server, SOL_TCP, TCP_QUICKACK, &yes, sizeof(yes));
-  errno = 0;
-
-  // open our ears to incoming connections; so_reuseport makes it
-  // possible for our many threads to bind to the same interface!
-  // otherwise we'd need to create a complex multi-threaded queue
-  if (bind(server, (struct sockaddr *)&addr, sizeof(addr)) == -1) {
-    kprintf("\r\e[Ksocket() returned %m\n");
-    goto CloseWorker;
-  }
-  unassert(!listen(server, 1));
+  pthread_setname_np(pthread_self(), "Worker");
 
   // connection loop
-  ++a_listening;
-  SomethingImportantHappened();
   while (!a_termsig) {
-    uint32_t clientaddrsize;
+    int client;
+    uint32_t clientsize;
+    int inmsglen, outmsglen;
     struct sockaddr_in clientaddr;
-    int client, inmsglen, outmsglen;
-    char inbuf[512], outbuf[512], *p, *q;
+    char inbuf[1500], outbuf[1500], *p, *q;
 
     // musl libc and cosmopolitan libc support a posix thread extension
     // that makes thread cancelation work much better. your io routines
-    // will just raise ECANCELED so you can check for cancellation with
+    // will just raise ECANCELED, so you can check for cancelation with
     // normal logic rather than needing to push and pop cleanup handler
     // functions onto the stack, or worse dealing with async interrupts
     unassert(!pthread_setcancelstate(PTHREAD_CANCEL_MASKED, 0));
 
     // wait for client connection
-    // we don't bother with poll() because this is actually very speedy
-    clientaddrsize = sizeof(clientaddr);
-    client = accept(server, (struct sockaddr *)&clientaddr, &clientaddrsize);
+    clientsize = sizeof(clientaddr);
+    client = accept(server, (struct sockaddr *)&clientaddr, &clientsize);
 
-    // turns cancellation off so we don't interrupt active http clients
+    // turn cancel off, so we don't need to check write() for ecanceled
     unassert(!pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, 0));
 
     if (client == -1) {
-      if (errno != EAGAIN && errno != ECANCELED) {
-        kprintf("\r\e[Kaccept() returned %m\n");
-        if (errno == ENFILE || errno == EMFILE) {
-          goto TooManyFileDescriptors;
-        }
-        usleep(10000);
-      }
+      // accept() errors are generally ephemeral or recoverable
+      // it'd potentially be a good idea to exponential backoff here
+      if (errno == ECANCELED) continue;  // pthread_cancel() was called
+      LOG("accept() returned %m");
+      SomethingHappened();
       continue;
     }
 
+    // this causes read() and write() to raise eagain after some time
+    struct timeval timeo = {KEEPALIVE / 1000, KEEPALIVE % 1000};
+    setsockopt(client, SOL_SOCKET, SO_RCVTIMEO, &timeo, sizeof(timeo));
+    setsockopt(client, SOL_SOCKET, SO_SNDTIMEO, &timeo, sizeof(timeo));
+
+    // log the incoming http message
+    unsigned clientip = ntohl(clientaddr.sin_addr.s_addr);
     ++a_connections;
+    LOG("%6H accepted connection from %hhu.%hhu.%hhu.%hhu:%hu", clientip >> 24,
+        clientip >> 16, clientip >> 8, clientip, ntohs(clientaddr.sin_port));
     SomethingHappened();
+    (void)clientip;
 
     // message loop
     ssize_t got, sent;
     struct HttpMessage msg;
     do {
-      // parse the incoming http message
-      InitHttpMessage(&msg, kHttpRequest);
-      // wait for http message (non-fragmented required)
-      // we're not terrible concerned when errors happen here
-      unassert(!pthread_setcancelstate(PTHREAD_CANCEL_MASKED, 0));
-      if ((got = read(client, inbuf, sizeof(inbuf))) <= 0) break;
-      unassert(!pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, 0));
-      // check that client message wasn't fragmented into more reads
-      if ((inmsglen = ParseHttpMessage(&msg, inbuf, got)) <= 0) break;
-      ++a_messages;
-      SomethingHappened();
 
-#if LOGGING
-      // log the incoming http message
-      unsigned clientip = ntohl(clientaddr.sin_addr.s_addr);
-      kprintf("\r\e[K%6P get some %hhu.%hhu.%hhu.%hhu:%hu %#.*s\n",
-              clientip >> 24, clientip >> 16, clientip >> 8, clientip,
-              ntohs(clientaddr.sin_port), msg.uri.b - msg.uri.a,
-              inbuf + msg.uri.a);
+      // wait for next http message (non-fragmented required)
+      unassert(!pthread_setcancelstate(PTHREAD_CANCEL_MASKED, 0));
+      got = read(client, inbuf, sizeof(inbuf));
+      for (int i = 0; i < got; ++i) {
+        if (!inbuf[i]) inbuf[i] = 1;
+      }
+      unassert(!pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, 0));
+      if (got <= 0) {
+        if (!got) {
+          LOG("%6H client disconnected");
+        } else if (errno == EAGAIN) {
+          LOG("%6H client timed out");
+        } else if (errno == ECANCELED) {
+          LOG("%6H disconnecting client due to shutdown");
+        } else {
+          LOG("%6H read() returned %m");
+        }
+        SomethingHappened();
+        break;
+      }
+
+      // check that client message wasn't fragmented into more reads
+      InitHttpMessage(&msg, kHttpRequest);
+      if ((inmsglen = ParseHttpMessage(&msg, inbuf, got)) <= 0) {
+        if (!inmsglen) {
+          LOG("%6H client sent fragmented message");
+        } else {
+          LOG("%6H client sent bad message");
+        }
+        SomethingHappened();
+        break;
+      }
+
+      // update server status with details of new message
+      ++a_messages;
+      LOG("%6H received message from %hhu.%hhu.%hhu.%hhu:%hu for path %#.*s",
+          clientip >> 24, clientip >> 16, clientip >> 8, clientip,
+          ntohs(clientaddr.sin_port), msg.uri.b - msg.uri.a, inbuf + msg.uri.a);
       SomethingHappened();
-#endif
 
       // display hello world html page for http://127.0.0.1:8080/
       struct tm tm;
@@ -226,9 +219,6 @@ void *Worker(void *id) {
         p = FormatHttpDateTime(p, gmtime_r(&unixts, &tm));
         p = stpcpy(p, "\r\nContent-Length: ");
         p = FormatInt32(p, strlen(q));
-        if (alwaysclose) {
-          p = stpcpy(p, "\r\nConnection: close");
-        }
         p = stpcpy(p, "\r\n\r\n");
         p = stpcpy(p, q);
         outmsglen = p - outbuf;
@@ -247,9 +237,6 @@ void *Worker(void *id) {
         p = FormatHttpDateTime(p, gmtime_r(&unixts, &tm));
         p = stpcpy(p, "\r\nContent-Length: ");
         p = FormatInt32(p, strlen(q));
-        if (alwaysclose) {
-          p = stpcpy(p, "\r\nConnection: close");
-        }
         p = stpcpy(p, "\r\n\r\n");
         p = stpcpy(p, q);
         outmsglen = p - outbuf;
@@ -260,36 +247,29 @@ void *Worker(void *id) {
       // amount, then since we sent the content length and checked
       // that the client didn't attach a payload, we are so synced
       // thus we can safely process more messages
-    } while (!alwaysclose &&       //
-             got == inmsglen &&    //
+    } while (got == inmsglen &&    //
              sent == outmsglen &&  //
              !msg.headers[kHttpContentLength].a &&
              !msg.headers[kHttpTransferEncoding].a &&
              (msg.method == kHttpGet || msg.method == kHttpHead));
+
     DestroyHttpMessage(&msg);
-    close(client);
     --a_connections;
     SomethingHappened();
+    close(client);
   }
-  --a_listening;
 
-  // inform the parent that this clone has finished
-CloseWorker:
-  close(server);
-WorkerFinished:
   --a_workers;
-
   SomethingImportantHappened();
   return 0;
 }
 
-void PrintStatus(void) {
+void PrintEphemeralStatusLine(void) {
   kprintf("\r\e[K\e[32mgreenbean\e[0m "
           "workers=%d "
-          "listening=%d "
           "connections=%d "
           "messages=%d%s ",
-          a_workers, a_listening, a_connections, a_messages, status);
+          a_workers, a_connections, a_messages, status);
 }
 
 void OnTerm(int sig) {
@@ -312,29 +292,38 @@ int main(int argc, char *argv[]) {
   unassert(!sigaction(SIGHUP, &sa, 0));
   unassert(!sigaction(SIGTERM, &sa, 0));
 
-  // print all the ips that 0.0.0.0 would bind
-  // Cosmo's GetHostIps() API is much easier than ioctl(SIOCGIFCONF)
-  uint32_t *hostips;
-  for (hostips = gc(GetHostIps()), i = 0; hostips[i]; ++i) {
-    kprintf("listening on http://%hhu.%hhu.%hhu.%hhu:%hu\n", hostips[i] >> 24,
-            hostips[i] >> 16, hostips[i] >> 8, hostips[i], PORT);
-  }
-
   // you can pass the number of threads you want as the first command arg
-  threads = argc > 1 ? atoi(argv[1]) : __get_cpu_count();
+  int threads = argc > 1 ? atoi(argv[1]) : __get_cpu_count();
   if (!(1 <= threads && threads <= 100000)) {
-    kprintf("\r\e[Kerror: invalid number of threads: %d\n", threads);
+    tinyprint(2, "error: invalid number of threads\n", NULL);
     exit(1);
   }
 
-  // caveat emptor microsofties
-  if (IsWindows()) {
-    kprintf("sorry but windows isn't supported by the greenbean demo yet\n"
-            "because it doesn't support SO_REUSEPORT which is a nice for\n"
-            "gaining great performance on UNIX systems, with simple code\n"
-            "however windows will work fine if we limit it to one thread\n");
-    threads = 1;      // we're going to make just one web server thread
-    alwaysclose = 1;  // don't let client idle, since it'd block others
+  // create listening socket that'll be shared by threads
+  int yes = 1;
+  struct sockaddr_in addr = {.sin_family = AF_INET, .sin_port = htons(PORT)};
+  server = socket(AF_INET, SOCK_STREAM, 0);
+  if (server == -1) {
+    perror("socket");
+    exit(1);
+  }
+  setsockopt(server, SOL_TCP, TCP_FASTOPEN, &yes, sizeof(yes));
+  setsockopt(server, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes));
+  if (bind(server, (struct sockaddr *)&addr, sizeof(addr)) == -1) {
+    perror("bind");
+    exit(1);
+  }
+  if (listen(server, SOMAXCONN)) {
+    perror("listen");
+    exit(1);
+  }
+
+  // print all the ips that 0.0.0.0 would bind
+  // Cosmo's GetHostIps() API is much easier than ioctl(SIOCGIFCONF)
+  uint32_t *hostips;
+  for (hostips = _gc(GetHostIps()), i = 0; hostips[i]; ++i) {
+    kprintf("listening on http://%hhu.%hhu.%hhu.%hhu:%hu\n", hostips[i] >> 24,
+            hostips[i] >> 16, hostips[i] >> 8, hostips[i], PORT);
   }
 
   // secure the server
@@ -385,14 +374,16 @@ int main(int argc, char *argv[]) {
   unassert(!pthread_attr_setstacksize(&attr, 65536));
   unassert(!pthread_attr_setguardsize(&attr, pagesz));
   unassert(!pthread_attr_setsigmask_np(&attr, &block));
-  pthread_t *th = gc(calloc(threads, sizeof(pthread_t)));
+  unassert(!pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, 0));
+  pthread_t *th = _gc(calloc(threads, sizeof(pthread_t)));
   for (i = 0; i < threads; ++i) {
     int rc;
     ++a_workers;
     if ((rc = pthread_create(th + i, &attr, Worker, (void *)(intptr_t)i))) {
       --a_workers;
-      kprintf("\r\e[Kpthread_create failed: %s\n", strerror(rc));
+      kprintf("pthread_create failed: %s\n", strerror(rc));
       if (rc == EAGAIN) {
+        kprintf("sudo prlimit --pid=$$ --nofile=%d\n", threads * 2);
         kprintf("sudo prlimit --pid=$$ --nproc=%d\n", threads * 2);
       }
       if (!i) exit(1);
@@ -400,17 +391,21 @@ int main(int argc, char *argv[]) {
       break;
     }
     if (!(i % 50)) {
-      PrintStatus();
+      PrintEphemeralStatusLine();
     }
   }
   unassert(!pthread_attr_destroy(&attr));
 
-  // wait for workers to terminate
+  // show status line on terminal until terminated
+  struct timespec tick = timespec_real();
   unassert(!pthread_mutex_lock(&statuslock));
   while (!a_termsig) {
-    PrintStatus();
+    PrintEphemeralStatusLine();
     unassert(!pthread_cond_wait(&statuscond, &statuslock));
-    usleep(10 * 1000);
+    // limit status line updates to sixty frames per second
+    do tick = timespec_add(tick, (struct timespec){0, 1e9 / 60});
+    while (timespec_cmp(tick, timespec_real()) < 0);
+    clock_nanosleep(CLOCK_REALTIME, TIMER_ABSTIME, &tick, 0);
   }
   unassert(!pthread_mutex_unlock(&statuslock));
 
@@ -421,11 +416,14 @@ int main(int argc, char *argv[]) {
     pthread_cancel(th[i]);
   }
 
+  // on windows this is the only way accept() can be canceled
+  if (IsWindows()) close(server);
+
   // print status in terminal as the shutdown progresses
   unassert(!pthread_mutex_lock(&statuslock));
   while (a_workers) {
     unassert(!pthread_cond_wait(&statuscond, &statuslock));
-    PrintStatus();
+    PrintEphemeralStatusLine();
   }
   unassert(!pthread_mutex_unlock(&statuslock));
 
@@ -434,19 +432,18 @@ int main(int argc, char *argv[]) {
     unassert(!pthread_join(th[i], 0));
   }
 
+  // close the server socket
+  if (!IsWindows()) close(server);
+
   // clean up terminal line
-  kprintf("\r\e[Kthank you for choosing \e[32mgreenbean\e[0m\n");
+  LOG("thank you for choosing \e[32mgreenbean\e[0m");
 
   // clean up more resources
-  unassert(!pthread_mutex_destroy(&statuslock));
   unassert(!pthread_cond_destroy(&statuscond));
+  unassert(!pthread_mutex_destroy(&statuslock));
 
   // quality assurance
   if (IsModeDbg()) {
     CheckForMemoryLeaks();
   }
-
-  // propagate termination signal
-  signal(a_termsig, SIG_DFL);
-  raise(a_termsig);
 }
diff --git a/examples/greenbean2.c b/examples/greenbean2.c
deleted file mode 100644
index 2b029b2e9..000000000
--- a/examples/greenbean2.c
+++ /dev/null
@@ -1,515 +0,0 @@
-#if 0
-/*─────────────────────────────────────────────────────────────────╗
-│ To the extent possible under law, Justine Tunney has waived      │
-│ all copyright and related or neighboring rights to this file,    │
-│ as it is written in the following disclaimers:                   │
-│   • http://unlicense.org/                                        │
-│   • http://creativecommons.org/publicdomain/zero/1.0/            │
-╚─────────────────────────────────────────────────────────────────*/
-#endif
-#include "libc/assert.h"
-#include "libc/atomic.h"
-#include "libc/calls/calls.h"
-#include "libc/calls/pledge.h"
-#include "libc/calls/struct/sigaction.h"
-#include "libc/calls/struct/timespec.h"
-#include "libc/calls/struct/timeval.h"
-#include "libc/dce.h"
-#include "libc/errno.h"
-#include "libc/fmt/conv.h"
-#include "libc/fmt/itoa.h"
-#include "libc/intrin/kprintf.h"
-#include "libc/log/log.h"
-#include "libc/macros.internal.h"
-#include "libc/mem/gc.internal.h"
-#include "libc/mem/mem.h"
-#include "libc/runtime/runtime.h"
-#include "libc/sock/sock.h"
-#include "libc/sock/struct/sockaddr.h"
-#include "libc/str/str.h"
-#include "libc/sysv/consts/af.h"
-#include "libc/sysv/consts/auxv.h"
-#include "libc/sysv/consts/sig.h"
-#include "libc/sysv/consts/so.h"
-#include "libc/sysv/consts/sock.h"
-#include "libc/sysv/consts/sol.h"
-#include "libc/sysv/consts/tcp.h"
-#include "libc/thread/thread.h"
-#include "libc/thread/thread2.h"
-#include "net/http/http.h"
-#include "third_party/nsync/cv.h"
-#include "third_party/nsync/mu.h"
-#include "third_party/nsync/time.h"
-
-/**
- * @fileoverview greenbean lightweight threaded web server no. 2
- *
- * This web server is the same as greenbean.c except it supports having
- * more than one thread on Windows. To do that we have to make the code
- * more complicated by not using SO_REUSEPORT. The approach we take, is
- * creating a single listener thread which adds accepted sockets into a
- * queue that worker threads consume. This way, if you like Windows you
- * can easily have a web server with 10,000+ connections.
- */
-
-#define PORT      8080
-#define KEEPALIVE 30000
-#define LOGGING   1
-
-#define STANDARD_RESPONSE_HEADERS \
-  "Server: greenbean/1.o\r\n"     \
-  "Referrer-Policy: origin\r\n"   \
-  "Cache-Control: private; max-age=0\r\n"
-
-int server;
-int threads;
-pthread_t listener;
-atomic_int a_termsig;
-atomic_int a_workers;
-atomic_int a_messages;
-atomic_int a_connections;
-pthread_cond_t statuscond;
-pthread_mutex_t statuslock;
-const char *volatile status = "";
-
-struct Clients {
-  int pos;
-  int count;
-  pthread_mutex_t mu;
-  pthread_cond_t non_full;
-  pthread_cond_t non_empty;
-  struct Client {
-    int sock;
-    uint32_t size;
-    struct sockaddr_in addr;
-  } data[100];
-} g_clients;
-
-ssize_t Write(int fd, const char *s) {
-  return write(fd, s, strlen(s));
-}
-
-void SomethingHappened(void) {
-  unassert(!pthread_cond_signal(&statuscond));
-}
-
-void SomethingImportantHappened(void) {
-  unassert(!pthread_mutex_lock(&statuslock));
-  unassert(!pthread_cond_signal(&statuscond));
-  unassert(!pthread_mutex_unlock(&statuslock));
-}
-
-bool AddClient(struct Clients *q, const struct Client *v,
-               struct timespec *deadline) {
-  bool wake = false;
-  bool added = false;
-  pthread_mutex_lock(&q->mu);
-  while (q->count == ARRAYLEN(q->data)) {
-    if (pthread_cond_timedwait(&q->non_full, &q->mu, deadline)) {
-      break;  // must be ETIMEDOUT or ECANCELED
-    }
-  }
-  if (q->count != ARRAYLEN(q->data)) {
-    int i = q->pos + q->count;
-    if (ARRAYLEN(q->data) <= i) i -= ARRAYLEN(q->data);
-    memcpy(q->data + i, v, sizeof(*v));
-    if (!q->count) wake = true;
-    q->count++;
-    added = true;
-  }
-  pthread_mutex_unlock(&q->mu);
-  if (wake) pthread_cond_signal(&q->non_empty);
-  return added;
-}
-
-int GetClient(struct Clients *q, struct Client *out) {
-  int got = 0, len = 1;
-  pthread_mutex_lock(&q->mu);
-  while (!q->count) {
-    errno_t err;
-    unassert(!pthread_setcancelstate(PTHREAD_CANCEL_MASKED, 0));
-    err = pthread_cond_wait(&q->non_empty, &q->mu);
-    unassert(!pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, 0));
-    if (err) {
-      unassert(err == ECANCELED);
-      break;
-    }
-  }
-  while (got < len && q->count) {
-    memcpy(out + got, q->data + q->pos, sizeof(*out));
-    if (q->count == ARRAYLEN(q->data)) {
-      pthread_cond_broadcast(&q->non_full);
-    }
-    ++got;
-    q->pos++;
-    q->count--;
-    if (q->pos == ARRAYLEN(q->data)) q->pos = 0;
-  }
-  pthread_mutex_unlock(&q->mu);
-  return got;
-}
-
-void *ListenWorker(void *arg) {
-  int yes = 1;
-  pthread_setname_np(pthread_self(), "Listener");
-
-  // load balance incoming connections for port 8080 across all threads
-  // hangup on any browser clients that lag for more than a few seconds
-  struct timeval timeo = {KEEPALIVE / 1000, KEEPALIVE % 1000};
-  struct sockaddr_in addr = {.sin_family = AF_INET, .sin_port = htons(PORT)};
-
-  server = socket(AF_INET, SOCK_STREAM, 0);
-  if (server == -1) {
-    kprintf("\r\e[Ksocket() failed %m\n");
-    SomethingHappened();
-    return 0;
-  }
-
-  // we don't bother checking for errors here since OS support for the
-  // advanced features tends to be a bit spotty and harmless to ignore
-  setsockopt(server, SOL_SOCKET, SO_RCVTIMEO, &timeo, sizeof(timeo));
-  setsockopt(server, SOL_SOCKET, SO_SNDTIMEO, &timeo, sizeof(timeo));
-  setsockopt(server, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes));
-  setsockopt(server, SOL_TCP, TCP_FASTOPEN, &yes, sizeof(yes));
-  setsockopt(server, SOL_TCP, TCP_QUICKACK, &yes, sizeof(yes));
-  errno = 0;
-
-  // open our ears to incoming connections; so_reuseport makes it
-  // possible for our many threads to bind to the same interface!
-  // otherwise we'd need to create a complex multi-threaded queue
-  if (bind(server, (struct sockaddr *)&addr, sizeof(addr)) == -1) {
-    kprintf("\r\e[Kbind() returned %m\n");
-    SomethingHappened();
-    goto CloseServer;
-  }
-  unassert(!listen(server, 1));
-
-  while (!a_termsig) {
-    struct Client client;
-
-    // musl libc and cosmopolitan libc support a posix thread extension
-    // that makes thread cancelation work much better. your io routines
-    // will just raise ECANCELED, so you can check for cancelation with
-    // normal logic rather than needing to push and pop cleanup handler
-    // functions onto the stack, or worse dealing with async interrupts
-    unassert(!pthread_setcancelstate(PTHREAD_CANCEL_MASKED, 0));
-
-    // wait for client connection
-    client.size = sizeof(client.addr);
-    client.sock = accept(server, (struct sockaddr *)&client.addr, &client.size);
-
-    // turn cancel off, so we don't need to check write() for ecanceled
-    unassert(!pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, 0));
-
-    if (client.sock == -1) {
-      // accept() errors are generally ephemeral or recoverable
-      if (errno == EAGAIN) continue;     // SO_RCVTIMEO interval churns
-      if (errno == ECANCELED) continue;  // pthread_cancel() was called
-      kprintf("\r\e[Kaccept() returned %m\n");
-      SomethingHappened();
-      usleep(10000);
-      errno = 0;
-      continue;
-    }
-
-#if LOGGING
-    // log the incoming http message
-    unsigned clientip = ntohl(client.addr.sin_addr.s_addr);
-    kprintf("\r\e[K%6P accepted connection from %hhu.%hhu.%hhu.%hhu:%hu\n",
-            clientip >> 24, clientip >> 16, clientip >> 8, clientip,
-            ntohs(client.addr.sin_port));
-    SomethingHappened();
-#endif
-
-    ++a_connections;
-    SomethingHappened();
-    struct timespec deadline =
-        timespec_add(timespec_real(), timespec_frommillis(100));
-    if (!AddClient(&g_clients, &client, &deadline)) {
-      Write(client.sock, "HTTP/1.1 503 Accept Queue Full\r\n"
-                         "Content-Type: text/plain\r\n"
-                         "Connection: close\r\n"
-                         "\r\n"
-                         "Accept Queue Full\n");
-      close(client.sock);
-    }
-  }
-
-CloseServer:
-  SomethingHappened();
-  close(server);
-  return 0;
-}
-
-void *Worker(void *id) {
-  pthread_setname_np(pthread_self(), "Worker");
-
-  // connection loop
-  while (!a_termsig) {
-    struct Client client;
-    int inmsglen, outmsglen;
-    char inbuf[512], outbuf[512], *p, *q;
-
-    // find a client to serve
-    if (!GetClient(&g_clients, &client)) {
-      continue;  // should be due to ecanceled
-    }
-
-    // message loop
-    ssize_t got, sent;
-    struct HttpMessage msg;
-    do {
-      // parse the incoming http message
-      InitHttpMessage(&msg, kHttpRequest);
-      // wait for http message (non-fragmented required)
-      // we're not terribly concerned when errors happen here
-      unassert(!pthread_setcancelstate(PTHREAD_CANCEL_MASKED, 0));
-      if ((got = read(client.sock, inbuf, sizeof(inbuf))) <= 0) break;
-      unassert(!pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, 0));
-      // check that client message wasn't fragmented into more reads
-      if ((inmsglen = ParseHttpMessage(&msg, inbuf, got)) <= 0) break;
-      ++a_messages;
-      SomethingHappened();
-
-#if LOGGING
-      // log the incoming http message
-      unsigned clientip = ntohl(client.addr.sin_addr.s_addr);
-      kprintf("\r\e[K%6P get some %hhu.%hhu.%hhu.%hhu:%hu %#.*s\n",
-              clientip >> 24, clientip >> 16, clientip >> 8, clientip,
-              ntohs(client.addr.sin_port), msg.uri.b - msg.uri.a,
-              inbuf + msg.uri.a);
-      SomethingHappened();
-#endif
-
-      // display hello world html page for http://127.0.0.1:8080/
-      struct tm tm;
-      int64_t unixts;
-      struct timespec ts;
-      if (msg.method == kHttpGet &&
-          (msg.uri.b - msg.uri.a == 1 && inbuf[msg.uri.a + 0] == '/')) {
-        q = "<!doctype html>\r\n"
-            "<title>hello world</title>\r\n"
-            "<h1>hello world</h1>\r\n"
-            "<p>this is a fun webpage\r\n"
-            "<p>hosted by greenbean\r\n";
-        p = stpcpy(outbuf, "HTTP/1.1 200 OK\r\n" STANDARD_RESPONSE_HEADERS
-                           "Content-Type: text/html; charset=utf-8\r\n"
-                           "Date: ");
-        clock_gettime(0, &ts), unixts = ts.tv_sec;
-        p = FormatHttpDateTime(p, gmtime_r(&unixts, &tm));
-        p = stpcpy(p, "\r\nContent-Length: ");
-        p = FormatInt32(p, strlen(q));
-        p = stpcpy(p, "\r\n\r\n");
-        p = stpcpy(p, q);
-        outmsglen = p - outbuf;
-        sent = write(client.sock, outbuf, outmsglen);
-
-      } else {
-        // display 404 not found error page for every thing else
-        q = "<!doctype html>\r\n"
-            "<title>404 not found</title>\r\n"
-            "<h1>404 not found</h1>\r\n";
-        p = stpcpy(outbuf,
-                   "HTTP/1.1 404 Not Found\r\n" STANDARD_RESPONSE_HEADERS
-                   "Content-Type: text/html; charset=utf-8\r\n"
-                   "Date: ");
-        clock_gettime(0, &ts), unixts = ts.tv_sec;
-        p = FormatHttpDateTime(p, gmtime_r(&unixts, &tm));
-        p = stpcpy(p, "\r\nContent-Length: ");
-        p = FormatInt32(p, strlen(q));
-        p = stpcpy(p, "\r\n\r\n");
-        p = stpcpy(p, q);
-        outmsglen = p - outbuf;
-        sent = write(client.sock, outbuf, p - outbuf);
-      }
-
-      // if the client isn't pipelining and write() wrote the full
-      // amount, then since we sent the content length and checked
-      // that the client didn't attach a payload, we are so synced
-      // thus we can safely process more messages
-    } while (got == inmsglen &&    //
-             sent == outmsglen &&  //
-             !msg.headers[kHttpContentLength].a &&
-             !msg.headers[kHttpTransferEncoding].a &&
-             (msg.method == kHttpGet || msg.method == kHttpHead));
-    DestroyHttpMessage(&msg);
-    kprintf("\r\e[K%6P client disconnected\n");
-    SomethingHappened();
-    close(client.sock);
-    --a_connections;
-    SomethingHappened();
-  }
-
-  --a_workers;
-  SomethingImportantHappened();
-  return 0;
-}
-
-void PrintStatus(void) {
-  kprintf("\r\e[K\e[32mgreenbean\e[0m "
-          "workers=%d "
-          "connections=%d "
-          "messages=%d%s ",
-          a_workers, a_connections, a_messages, status);
-}
-
-void OnTerm(int sig) {
-  a_termsig = sig;
-  status = " shutting down...";
-  SomethingHappened();
-}
-
-int main(int argc, char *argv[]) {
-  int i;
-
-  // print cpu registers and backtrace on crash
-  // note that pledge'll makes backtraces worse
-  // you can press ctrl+\ to trigger backtraces
-  // ShowCrashReports();
-
-  // listen for ctrl-c, terminal close, and kill
-  struct sigaction sa = {.sa_handler = OnTerm};
-  unassert(!sigaction(SIGINT, &sa, 0));
-  unassert(!sigaction(SIGHUP, &sa, 0));
-  unassert(!sigaction(SIGTERM, &sa, 0));
-
-  // print all the ips that 0.0.0.0 would bind
-  // Cosmo's GetHostIps() API is much easier than ioctl(SIOCGIFCONF)
-  uint32_t *hostips;
-  for (hostips = gc(GetHostIps()), i = 0; hostips[i]; ++i) {
-    kprintf("listening on http://%hhu.%hhu.%hhu.%hhu:%hu\n", hostips[i] >> 24,
-            hostips[i] >> 16, hostips[i] >> 8, hostips[i], PORT);
-  }
-
-  // you can pass the number of threads you want as the first command arg
-  threads = argc > 1 ? atoi(argv[1]) : __get_cpu_count();
-  if (!(1 <= threads && threads <= 100000)) {
-    kprintf("\r\e[Kerror: invalid number of threads: %d\n", threads);
-    exit(1);
-  }
-
-  // secure the server
-  //
-  // pledge() and unveil() let us whitelist which system calls and files
-  // the server will be allowed to use. this way if it gets hacked, they
-  // won't be able to do much damage, like compromising the whole server
-  //
-  // pledge violations on openbsd are logged nicely to the system logger
-  // but on linux we need to use a cosmopolitan extension to get details
-  // although doing that slightly weakens the security pledge() provides
-  //
-  // if your operating system doesn't support these security features or
-  // is too old, then pledge() and unveil() don't consider this an error
-  // so it works. if security is critical there's a special call to test
-  // which is npassert(!pledge(0, 0)), and npassert(unveil("", 0) != -1)
-  __pledge_mode = PLEDGE_PENALTY_RETURN_EPERM;  // c. greenbean --strace
-  unveil("/dev/null", "rw");
-  unveil(0, 0);
-  pledge("stdio inet", 0);
-
-  // initialize our synchronization data structures, which were written
-  // by mike burrows in a library called *nsync we've tailored for libc
-  unassert(!pthread_cond_init(&statuscond, 0));
-  unassert(!pthread_mutex_init(&statuslock, 0));
-  unassert(!pthread_mutex_init(&g_clients.mu, 0));
-  unassert(!pthread_cond_init(&g_clients.non_full, 0));
-  unassert(!pthread_cond_init(&g_clients.non_empty, 0));
-
-  // spawn over 9000 worker threads
-  //
-  // you don't need weird i/o models, or event driven yoyo pattern code
-  // to build a massively scalable server. the secret is to use threads
-  // with tiny stacks. then you can write plain simple imperative code!
-  //
-  // we block signals in our worker threads so we won't need messy code
-  // to spin on eintr. operating systems also deliver signals to random
-  // threads, and we'd have ctrl-c, etc. be handled by the main thread.
-  //
-  // alternatively you can just use signal() instead of sigaction(); it
-  // uses SA_RESTART because all the syscalls the worker currently uses
-  // are documented as @restartable which means no EINTR toil is needed
-  sigset_t block;
-  sigemptyset(&block);
-  sigaddset(&block, SIGINT);
-  sigaddset(&block, SIGHUP);
-  sigaddset(&block, SIGQUIT);
-  pthread_attr_t attr;
-  int pagesz = getauxval(AT_PAGESZ);
-  unassert(!pthread_attr_init(&attr));
-  unassert(!pthread_attr_setstacksize(&attr, 65536));
-  unassert(!pthread_attr_setguardsize(&attr, pagesz));
-  unassert(!pthread_attr_setsigmask_np(&attr, &block));
-  unassert(!pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, 0));
-  unassert(!pthread_create(&listener, &attr, ListenWorker, 0));
-  pthread_t *th = gc(calloc(threads, sizeof(pthread_t)));
-  for (i = 0; i < threads; ++i) {
-    int rc;
-    ++a_workers;
-    if ((rc = pthread_create(th + i, &attr, Worker, (void *)(intptr_t)i))) {
-      --a_workers;
-      kprintf("\r\e[Kpthread_create failed: %s\n", strerror(rc));
-      if (rc == EAGAIN) {
-        kprintf("sudo prlimit --pid=$$ --nofile=%d\n", threads * 3);
-        kprintf("sudo prlimit --pid=$$ --nproc=%d\n", threads * 2);
-      }
-      if (!i) exit(1);
-      threads = i;
-      break;
-    }
-    if (!(i % 50)) {
-      PrintStatus();
-    }
-  }
-  unassert(!pthread_attr_destroy(&attr));
-
-  // wait for workers to terminate
-  unassert(!pthread_mutex_lock(&statuslock));
-  while (!a_termsig) {
-    PrintStatus();
-    unassert(!pthread_cond_wait(&statuscond, &statuslock));
-    usleep(10 * 1000);
-  }
-  unassert(!pthread_mutex_unlock(&statuslock));
-
-  // cancel all the worker threads so they shut down asap
-  // and it'll wait on active clients to gracefully close
-  // you've never seen a production server close so fast!
-  close(server);
-  pthread_cancel(listener);
-  for (i = 0; i < threads; ++i) {
-    pthread_cancel(th[i]);
-  }
-
-  // print status in terminal as the shutdown progresses
-  unassert(!pthread_mutex_lock(&statuslock));
-  while (a_workers) {
-    unassert(!pthread_cond_wait(&statuscond, &statuslock));
-    PrintStatus();
-  }
-  unassert(!pthread_mutex_unlock(&statuslock));
-
-  // wait for final termination and free thread memory
-  unassert(!pthread_join(listener, 0));
-  for (i = 0; i < threads; ++i) {
-    unassert(!pthread_join(th[i], 0));
-  }
-
-  // clean up terminal line
-  kprintf("\r\e[Kthank you for choosing \e[32mgreenbean\e[0m\n");
-
-  // clean up more resources
-  unassert(!pthread_cond_destroy(&statuscond));
-  unassert(!pthread_mutex_destroy(&statuslock));
-  unassert(!pthread_mutex_destroy(&g_clients.mu));
-  unassert(!pthread_cond_destroy(&g_clients.non_full));
-  unassert(!pthread_cond_destroy(&g_clients.non_empty));
-
-  // quality assurance
-  if (IsModeDbg()) {
-    CheckForMemoryLeaks();
-  }
-
-  // propagate termination signal
-  signal(a_termsig, SIG_DFL);
-  raise(a_termsig);
-}
diff --git a/libc/calls/mkntpath.c b/libc/calls/mkntpath.c
index 60fdd2ae4..b5dff0289 100644
--- a/libc/calls/mkntpath.c
+++ b/libc/calls/mkntpath.c
@@ -54,6 +54,35 @@ textwindows static const char *FixNtMagicPath(const char *path,
   return path;
 }
 
+textwindows size_t __normntpath(char16_t *p, size_t n) {
+  size_t i, j;
+  for (j = i = 0; i < n; ++i) {
+    int c = p[i];
+    if (c == '/') {
+      c = '\\';
+    }
+    if (j > 1 && c == '\\' && p[j - 1] == '\\') {
+      // matched "^/" or "//" but not "^//"
+    } else if ((j && p[j - 1] == '\\') &&  //
+               c == '.' &&                 //
+               (i + 1 == n || IsSlash(p[i + 1]))) {
+      // matched "/./" or "/.$"
+      i += !(i + 1 == n);
+    } else if ((j && p[j - 1] == '\\') &&         //
+               c == '.' &&                        //
+               (i + 1 < n && p[i + 1] == '.') &&  //
+               (i + 2 == n || IsSlash(p[i + 2]))) {
+      // matched "/../" or "/..$"
+      while (j && p[j - 1] == '\\') --j;
+      while (j && p[j - 1] != '\\') --j;
+    } else {
+      p[j++] = c;
+    }
+  }
+  p[j] = 0;
+  return j;
+}
+
 textwindows int __mkntpath(const char *path,
                            char16_t path16[hasatleast PATH_MAX]) {
   return __mkntpath2(path, path16, -1);
@@ -78,7 +107,6 @@ textwindows int __mkntpath(const char *path,
  */
 textwindows int __mkntpath2(const char *path,
                             char16_t path16[hasatleast PATH_MAX], int flags) {
-
   // 1. Need +1 for NUL-terminator
   // 2. Need +1 for UTF-16 overflow
   // 3. Need ≥2 for SetCurrentDirectory trailing slash requirement
@@ -165,32 +193,7 @@ textwindows int __mkntpath2(const char *path,
   // normalize path
   // we need it because \\?\... paths have to be normalized
   // we don't remove the trailing slash since it is special
-  size_t i, j;
-  for (j = i = 0; i < n; ++i) {
-    int c = p[i];
-    if (c == '/') {
-      c = '\\';
-    }
-    if (j > 1 && c == '\\' && p[j - 1] == '\\') {
-      // matched "^/" or "//" but not "^//"
-    } else if ((j && p[j - 1] == '\\') &&  //
-               c == '.' &&                 //
-               (i + 1 == n || IsSlash(p[i + 1]))) {
-      // matched "/./" or "/.$"
-      i += !(i + 1 == n);
-    } else if ((j && p[j - 1] == '\\') &&         //
-               c == '.' &&                        //
-               (i + 1 < n && p[i + 1] == '.') &&  //
-               (i + 2 == n || IsSlash(p[i + 2]))) {
-      // matched "/../" or "/..$"
-      while (j && p[j - 1] == '\\') --j;
-      while (j && p[j - 1] != '\\') --j;
-    } else {
-      p[j++] = c;
-    }
-  }
-  p[j] = 0;
-  n = j;
+  n = __normntpath(p, n);
 
   // our path is now stored at `path16` with length `n`
   n = x + m + n;
diff --git a/libc/calls/mkntpathat.c b/libc/calls/mkntpathat.c
index f71bed04a..ee562bda2 100644
--- a/libc/calls/mkntpathat.c
+++ b/libc/calls/mkntpathat.c
@@ -27,37 +27,35 @@
 #include "libc/sysv/consts/at.h"
 #include "libc/sysv/errfuns.h"
 
-static int __mkntpathat_impl(int dirfd, const char *path, int flags,
-                             char16_t file[hasatleast PATH_MAX]) {
+static textwindows int __mkntpathath_impl(int64_t dirhand, const char *path,
+                                          int flags,
+                                          char16_t file[hasatleast PATH_MAX]) {
+  size_t n;
   char16_t dir[PATH_MAX];
   uint32_t dirlen, filelen;
   if (!isutf8(path, -1)) return eilseq();  // thwart overlong nul in conversion
   if ((filelen = __mkntpath2(path, file, flags)) == -1) return -1;
   if (!filelen) return enoent();
-  if (file[0] != u'\\' && dirfd != AT_FDCWD) {  // ProTip: \\?\C:\foo
-    if (!__isfdkind(dirfd, kFdFile)) return ebadf();
-    dirlen = GetFinalPathNameByHandle(g_fds.p[dirfd].handle, dir, ARRAYLEN(dir),
+  if (file[0] != u'\\' && dirhand != AT_FDCWD) {  // ProTip: \\?\C:\foo
+    dirlen = GetFinalPathNameByHandle(dirhand, dir, ARRAYLEN(dir),
                                       kNtFileNameNormalized | kNtVolumeNameDos);
     if (!dirlen) return __winerr();
-    if (dirlen + 1 + filelen + 1 > ARRAYLEN(dir)) {
-      STRACE("path too long: %#.*hs\\%#.*hs", dirlen, dir, filelen, file);
-      return enametoolong();
-    }
+    if (dirlen + 1 + filelen + 1 > ARRAYLEN(dir)) return enametoolong();
     dir[dirlen] = u'\\';
     memcpy(dir + dirlen + 1, file, (filelen + 1) * sizeof(char16_t));
-    memcpy(file, dir, (dirlen + 1 + filelen + 1) * sizeof(char16_t));
-    return dirlen + 1 + filelen;
+    memcpy(file, dir, ((n = dirlen + 1 + filelen) + 1) * sizeof(char16_t));
+    return __normntpath(file, n);
   } else {
     return filelen;
   }
 }
 
-int __mkntpathat(int dirfd, const char *path, int flags,
-                 char16_t file[hasatleast PATH_MAX]) {
+textwindows int __mkntpathath(int64_t dirhand, const char *path, int flags,
+                              char16_t file[hasatleast PATH_MAX]) {
 
   // convert the path.
   int len;
-  if ((len = __mkntpathat_impl(dirfd, path, flags, file)) == -1) {
+  if ((len = __mkntpathath_impl(dirhand, path, flags, file)) == -1) {
     return -1;
   }
 
@@ -78,3 +76,16 @@ int __mkntpathat(int dirfd, const char *path, int flags,
 
   return len;
 }
+
+textwindows int __mkntpathat(int dirfd, const char *path, int flags,
+                             char16_t file[hasatleast PATH_MAX]) {
+  int64_t dirhand;
+  if (dirfd == AT_FDCWD) {
+    dirhand = AT_FDCWD;
+  } else if (__isfdkind(dirfd, kFdFile)) {
+    dirhand = g_fds.p[dirfd].handle;
+  } else {
+    return ebadf();
+  }
+  return __mkntpathath(dirhand, path, flags, file);
+}
diff --git a/libc/calls/ntspawn.c b/libc/calls/ntspawn.c
index dee93eabb..26014b92d 100644
--- a/libc/calls/ntspawn.c
+++ b/libc/calls/ntspawn.c
@@ -73,7 +73,7 @@ static void ntspawn_free(void *ptr) {
  * @asyncsignalsafe
  */
 textwindows int ntspawn(
-    const char *prog, char *const argv[], char *const envp[],
+    int64_t dirhand, const char *prog, char *const argv[], char *const envp[],
     char *const extravars[], uint32_t dwCreationFlags,
     const char16_t *opt_lpCurrentDirectory, int64_t opt_hParentProcess,
     int64_t *opt_lpExplicitHandleList, uint32_t dwExplicitHandleCount,
@@ -82,7 +82,8 @@ textwindows int ntspawn(
   int rc = -1;
   struct SpawnBlock *sb;
   BLOCK_SIGNALS;
-  if ((sb = ntspawn_malloc(sizeof(*sb))) && __mkntpath(prog, sb->path) != -1) {
+  if ((sb = ntspawn_malloc(sizeof(*sb))) &&
+      __mkntpathath(dirhand, prog, 0, sb->path) != -1) {
     if (!mkntcmdline(sb->cmdline, argv) &&
         !mkntenvblock(sb->envblock, envp, extravars, sb->envbuf)) {
       bool32 ok;
@@ -133,6 +134,8 @@ textwindows int ntspawn(
             STRACE("CreateProcess() failed w/ %d", GetLastError());
             if (GetLastError() == kNtErrorSharingViolation) {
               etxtbsy();
+            } else if (GetLastError() == kNtErrorInvalidName) {
+              enoent();
             }
           }
           rc = __fix_enotdir(rc, sb->path);
diff --git a/libc/calls/pledge.c b/libc/calls/pledge.c
index 74794e647..98a1173ad 100644
--- a/libc/calls/pledge.c
+++ b/libc/calls/pledge.c
@@ -24,6 +24,7 @@
 #include "libc/calls/syscall-sysv.internal.h"
 #include "libc/dce.h"
 #include "libc/errno.h"
+#include "libc/intrin/kprintf.h"
 #include "libc/intrin/promises.internal.h"
 #include "libc/intrin/strace.internal.h"
 #include "libc/nexgen32e/vendor.internal.h"
@@ -267,11 +268,13 @@ int pledge(const char *promises, const char *execpromises) {
       // if bits are missing in execpromises that exist in promises
       // then execpromises wouldn't be a monotonic access reduction
       // this check only matters when exec / execnative are allowed
-      if ((ipromises & ~iexecpromises) &&
-          (~ipromises & (1ul << PROMISE_EXEC))) {
+      bool notsubset = ((ipromises & ~iexecpromises) &&
+                        (~ipromises & (1ul << PROMISE_EXEC)));
+      if (notsubset && execpromises) {
         STRACE("execpromises must be a subset of promises");
         rc = einval();
       } else {
+        if (notsubset) iexecpromises = ipromises;
         rc = sys_pledge_linux(ipromises, __pledge_mode);
         if (rc > -4096u) errno = -rc, rc = -1;
       }
diff --git a/libc/calls/syscall_support-nt.internal.h b/libc/calls/syscall_support-nt.internal.h
index 15c2bef16..9fdaa7d80 100644
--- a/libc/calls/syscall_support-nt.internal.h
+++ b/libc/calls/syscall_support-nt.internal.h
@@ -10,9 +10,11 @@ bool isregularfile_nt(const char *);
 bool issymlink_nt(const char *);
 bool32 ntsetprivilege(int64_t, const char16_t *, uint32_t);
 char16_t *__create_pipe_name(char16_t *);
+size_t __normntpath(char16_t *, size_t);
 int __mkntpath(const char *, char16_t[hasatleast PATH_MAX]);
 int __mkntpath2(const char *, char16_t[hasatleast PATH_MAX], int);
 int __mkntpathat(int, const char *, int, char16_t[hasatleast PATH_MAX]);
+int __mkntpathath(int64_t, const char *, int, char16_t[hasatleast PATH_MAX]);
 int ntaccesscheck(const char16_t *, uint32_t) paramsnonnull();
 int sys_pause_nt(void);
 int64_t __fix_enotdir(int64_t, char16_t *);
diff --git a/libc/intrin/createprocess.c b/libc/intrin/createprocess.c
index 82bbc64f8..a2fb7eda4 100644
--- a/libc/intrin/createprocess.c
+++ b/libc/intrin/createprocess.c
@@ -45,7 +45,7 @@ CreateProcess(const char16_t *opt_lpApplicationName, char16_t *lpCommandLine,
                             opt_lpCurrentDirectory, lpStartupInfo,
                             opt_out_lpProcessInformation);
   if (!ok) __winerr();
-  NTTRACE("CreateProcess(%#hs, %#!hs, %s, %s, %hhhd, %u, %p, %#hs, %p, %p) → "
+  NTTRACE("CreateProcess(%#!hs, %#!hs, %s, %s, %hhhd, %u, %p, %#!hs, %p, %p) → "
           "%hhhd% m",
           opt_lpApplicationName, lpCommandLine,
           DescribeNtSecurityAttributes(opt_lpProcessAttributes),
diff --git a/libc/intrin/ulock.c b/libc/intrin/ulock.c
index 7adaeb951..c6d7437b5 100644
--- a/libc/intrin/ulock.c
+++ b/libc/intrin/ulock.c
@@ -39,8 +39,8 @@ int ulock_wait(uint32_t operation, void *addr, uint64_t value,
   LOCKTRACE("ulock_wait(%#x, %p, %lx, %u) → ...", operation, addr, value,
             timeout_micros);
   rc = sys_ulock_wait(operation, addr, value, timeout_micros);
-  STRACE("ulock_wait(%#x, %p, %lx, %u) → %d% m", operation, addr, value,
-         timeout_micros, rc);
+  LOCKTRACE("ulock_wait(%#x, %p, %lx, %u) → %d% m", operation, addr, value,
+            timeout_micros, rc);
   return rc;
 }
 
@@ -48,7 +48,7 @@ int ulock_wait(uint32_t operation, void *addr, uint64_t value,
 int ulock_wake(uint32_t operation, void *addr, uint64_t wake_value) {
   int rc;
   rc = __syscall3i(operation, (long)addr, wake_value, 0x2000000 | 516);
-  STRACE("ulock_wake(%#x, %p, %lx) → %s", operation, addr, wake_value,
-         DescribeErrno(rc));
+  LOCKTRACE("ulock_wake(%#x, %p, %lx) → %s", operation, addr, wake_value,
+            DescribeErrno(rc));
   return rc;
 }
diff --git a/libc/isystem/cosmo.h b/libc/isystem/cosmo.h
index 462e3aced..4ba2046b3 100644
--- a/libc/isystem/cosmo.h
+++ b/libc/isystem/cosmo.h
@@ -28,6 +28,7 @@
  */
 
 #include "libc/calls/calls.h"
+#include "libc/calls/pledge.h"
 #include "libc/calls/struct/timespec.h"
 #include "libc/calls/struct/timeval.h"
 #include "libc/cosmo.h"
@@ -59,6 +60,7 @@
 #include "libc/str/unicode.h"
 #include "libc/str/utf16.h"
 #include "libc/sysv/errfuns.h"
+#include "net/http/http.h"
 
 #ifdef COSMO_ALREADY_DEFINED
 #undef COSMO_ALREADY_DEFINED
diff --git a/libc/proc/execve-nt.greg.c b/libc/proc/execve-nt.greg.c
index e2989b0df..9894b6484 100644
--- a/libc/proc/execve-nt.greg.c
+++ b/libc/proc/execve-nt.greg.c
@@ -35,6 +35,7 @@
 #include "libc/proc/describefds.internal.h"
 #include "libc/proc/ntspawn.h"
 #include "libc/str/str.h"
+#include "libc/sysv/consts/at.h"
 #include "libc/sysv/consts/o.h"
 #include "libc/sysv/errfuns.h"
 #include "libc/thread/posixthread.internal.h"
@@ -85,9 +86,9 @@ textwindows int sys_execve_nt(const char *program, char *const argv[],
 
   // launch the process
   struct NtProcessInformation pi;
-  int rc =
-      ntspawn(program, argv, envp, (char *[]){fdspec, 0}, 0, 0, hParentProcess,
-              lpExplicitHandles, dwExplicitHandleCount, &si, &pi);
+  int rc = ntspawn(AT_FDCWD, program, argv, envp, (char *[]){fdspec, 0}, 0, 0,
+                   hParentProcess, lpExplicitHandles, dwExplicitHandleCount,
+                   &si, &pi);
   __undescribe_fds(hParentProcess, lpExplicitHandles, dwExplicitHandleCount);
   if (rc == -1) {
     free(fdspec);
diff --git a/libc/proc/fork-nt.c b/libc/proc/fork-nt.c
index acefcc354..6174035b4 100644
--- a/libc/proc/fork-nt.c
+++ b/libc/proc/fork-nt.c
@@ -58,6 +58,7 @@
 #include "libc/runtime/memtrack.internal.h"
 #include "libc/runtime/symbols.internal.h"
 #include "libc/str/str.h"
+#include "libc/sysv/consts/at.h"
 #include "libc/sysv/consts/limits.h"
 #include "libc/sysv/consts/map.h"
 #include "libc/sysv/consts/prot.h"
@@ -345,7 +346,7 @@ textwindows int sys_fork_nt(uint32_t dwCreationFlags) {
       }
 #endif
       NTTRACE("STARTING SPAWN");
-      int spawnrc = ntspawn(GetProgramExecutableName(), args, environ,
+      int spawnrc = ntspawn(AT_FDCWD, GetProgramExecutableName(), args, environ,
                             (char *[]){forkvar, 0}, dwCreationFlags, 0, 0, 0, 0,
                             &startinfo, &procinfo);
       if (spawnrc != -1) {
diff --git a/libc/proc/ntspawn.h b/libc/proc/ntspawn.h
index 853355c8f..3ec1c12b2 100644
--- a/libc/proc/ntspawn.h
+++ b/libc/proc/ntspawn.h
@@ -7,8 +7,8 @@ COSMOPOLITAN_C_START_
 
 int mkntcmdline(char16_t[32767], char *const[]);
 int mkntenvblock(char16_t[32767], char *const[], char *const[], char[32767]);
-int ntspawn(const char *, char *const[], char *const[], char *const[], uint32_t,
-            const char16_t *, int64_t, int64_t *, uint32_t,
+int ntspawn(int64_t, const char *, char *const[], char *const[], char *const[],
+            uint32_t, const char16_t *, int64_t, int64_t *, uint32_t,
             const struct NtStartupInfo *, struct NtProcessInformation *);
 
 COSMOPOLITAN_C_END_
diff --git a/libc/proc/posix_spawn.c b/libc/proc/posix_spawn.c
index 77d6170b1..959f7585f 100644
--- a/libc/proc/posix_spawn.c
+++ b/libc/proc/posix_spawn.c
@@ -44,6 +44,10 @@
 #include "libc/mem/alloca.h"
 #include "libc/mem/mem.h"
 #include "libc/nt/createfile.h"
+#include "libc/nt/enum/accessmask.h"
+#include "libc/nt/enum/creationdisposition.h"
+#include "libc/nt/enum/fileflagandattributes.h"
+#include "libc/nt/enum/filesharemode.h"
 #include "libc/nt/enum/processcreationflags.h"
 #include "libc/nt/enum/startf.h"
 #include "libc/nt/files.h"
@@ -176,15 +180,15 @@ static textwindows errno_t spawnfds_dup2(struct SpawnFds *fds, int fildes,
   return 0;
 }
 
-static textwindows errno_t spawnfds_open(struct SpawnFds *fds, int fildes,
-                                         const char *path, int oflag,
-                                         int mode) {
+static textwindows errno_t spawnfds_open(struct SpawnFds *fds, int64_t dirhand,
+                                         int fildes, const char *path,
+                                         int oflag, int mode) {
   int64_t h;
   errno_t err;
   char16_t path16[PATH_MAX];
   uint32_t perm, share, disp, attr;
   if ((err = spawnfds_ensure(fds, fildes))) return err;
-  if (__mkntpathat(AT_FDCWD, path, 0, path16) != -1 &&
+  if (__mkntpathath(dirhand, path, 0, path16) != -1 &&
       GetNtOpenFlags(oflag, mode, &perm, &share, &disp, &attr) != -1 &&
       (h = CreateFile(path16, perm, share, &kNtIsInheritable, disp, attr, 0))) {
     spawnfds_closelater(fds, h);
@@ -198,6 +202,39 @@ static textwindows errno_t spawnfds_open(struct SpawnFds *fds, int fildes,
   }
 }
 
+static textwindows errno_t spawnfds_chdir(struct SpawnFds *fds, int64_t dirhand,
+                                          const char *path,
+                                          int64_t *out_dirhand) {
+  int64_t h;
+  char16_t path16[PATH_MAX];
+  if (__mkntpathath(dirhand, path, 0, path16) != -1 &&
+      (h = CreateFile(path16, kNtFileGenericRead,
+                      kNtFileShareRead | kNtFileShareWrite | kNtFileShareDelete,
+                      0, kNtOpenExisting,
+                      kNtFileAttributeNormal | kNtFileFlagBackupSemantics,
+                      0))) {
+    spawnfds_closelater(fds, h);
+    *out_dirhand = h;
+    return 0;
+  } else {
+    return errno;
+  }
+}
+
+static textwindows errno_t spawnfds_fchdir(struct SpawnFds *fds, int fildes,
+                                           int64_t *out_dirhand) {
+  int64_t h;
+  if (spawnfds_exists(fds, fildes)) {
+    h = fds->p[fildes].handle;
+  } else if (__isfdopen(fildes)) {
+    h = g_fds.p[fildes].handle;
+  } else {
+    return EBADF;
+  }
+  *out_dirhand = h;
+  return 0;
+}
+
 static textwindows errno_t posix_spawn_nt_impl(
     int *pid, const char *path, const posix_spawn_file_actions_t *file_actions,
     const posix_spawnattr_t *attrp, char *const argv[], char *const envp[]) {
@@ -207,6 +244,7 @@ static textwindows errno_t posix_spawn_nt_impl(
   errno_t e = errno;
   struct Proc *proc = 0;
   struct SpawnFds fds = {0};
+  int64_t dirhand = AT_FDCWD;
   int64_t *lpExplicitHandles = 0;
   uint32_t dwExplicitHandleCount = 0;
   int64_t hCreatorProcess = GetCurrentProcess();
@@ -257,12 +295,27 @@ static textwindows errno_t posix_spawn_nt_impl(
           }
           break;
         case _POSIX_SPAWN_OPEN:
-          err = spawnfds_open(&fds, a->fildes, a->path, a->oflag, a->mode);
+          err = spawnfds_open(&fds, dirhand, a->fildes, a->path, a->oflag,
+                              a->mode);
           if (err) {
             STRACE("spawnfds_open(%d, %#s) failed", a->fildes, a->path);
             goto ReturnErr;
           }
           break;
+        case _POSIX_SPAWN_CHDIR:
+          err = spawnfds_chdir(&fds, dirhand, a->path, &dirhand);
+          if (err) {
+            STRACE("spawnfds_chdir(%#s) failed", a->path);
+            goto ReturnErr;
+          }
+          break;
+        case _POSIX_SPAWN_FCHDIR:
+          err = spawnfds_fchdir(&fds, a->fildes, &dirhand);
+          if (err) {
+            STRACE("spawnfds_fchdir(%d) failed", a->fildes);
+            goto ReturnErr;
+          }
+          break;
         default:
           __builtin_unreachable();
       }
@@ -289,15 +342,26 @@ static textwindows errno_t posix_spawn_nt_impl(
       .hStdError = spawnfds_handle(&fds, 2),
   };
 
+  // determine spawn directory
+  char16_t *lpCurrentDirectory = 0;
+  if (dirhand != AT_FDCWD) {
+    lpCurrentDirectory = alloca(PATH_MAX * sizeof(char16_t));
+    if (!GetFinalPathNameByHandle(dirhand, lpCurrentDirectory, PATH_MAX,
+                                  kNtFileNameNormalized | kNtVolumeNameDos)) {
+      err = GetLastError();
+      goto ReturnErr;
+    }
+  }
+
   // launch process
   int rc = -1;
   struct NtProcessInformation procinfo;
   if (!envp) envp = environ;
   if ((fdspec = __describe_fds(fds.p, fds.n, &startinfo, hCreatorProcess,
                                &lpExplicitHandles, &dwExplicitHandleCount))) {
-    rc = ntspawn(path, argv, envp, (char *[]){fdspec, 0}, dwCreationFlags, 0, 0,
-                 lpExplicitHandles, dwExplicitHandleCount, &startinfo,
-                 &procinfo);
+    rc = ntspawn(dirhand, path, argv, envp, (char *[]){fdspec, 0},
+                 dwCreationFlags, lpCurrentDirectory, 0, lpExplicitHandles,
+                 dwExplicitHandleCount, &startinfo, &procinfo);
   }
   if (rc == -1) {
     err = errno;
@@ -479,6 +543,16 @@ errno_t posix_spawn(int *pid, const char *path,
             }
             break;
           }
+          case _POSIX_SPAWN_CHDIR:
+            if (chdir(a->path) == -1) {
+              goto ChildFailed;
+            }
+            break;
+          case _POSIX_SPAWN_FCHDIR:
+            if (fchdir(a->fildes) == -1) {
+              goto ChildFailed;
+            }
+            break;
           default:
             __builtin_unreachable();
         }
diff --git a/libc/proc/posix_spawn.h b/libc/proc/posix_spawn.h
index df65a2ff6..9bc0cfd93 100644
--- a/libc/proc/posix_spawn.h
+++ b/libc/proc/posix_spawn.h
@@ -31,6 +31,9 @@ int posix_spawn_file_actions_addclose(posix_spawn_file_actions_t *, int);
 int posix_spawn_file_actions_adddup2(posix_spawn_file_actions_t *, int, int);
 int posix_spawn_file_actions_addopen(posix_spawn_file_actions_t *, int,
                                      const char *, int, unsigned);
+int posix_spawn_file_actions_addchdir_np(posix_spawn_file_actions_t *,
+                                         const char *);
+int posix_spawn_file_actions_addfchdir_np(posix_spawn_file_actions_t *, int);
 
 int posix_spawnattr_init(posix_spawnattr_t *);
 int posix_spawnattr_destroy(posix_spawnattr_t *);
diff --git a/libc/proc/posix_spawn.internal.h b/libc/proc/posix_spawn.internal.h
index 5d9cfefed..855774be1 100644
--- a/libc/proc/posix_spawn.internal.h
+++ b/libc/proc/posix_spawn.internal.h
@@ -5,9 +5,11 @@
 #include "libc/calls/struct/sigset.h"
 #include "libc/proc/posix_spawn.h"
 
-#define _POSIX_SPAWN_CLOSE 1
-#define _POSIX_SPAWN_DUP2  2
-#define _POSIX_SPAWN_OPEN  3
+#define _POSIX_SPAWN_CLOSE  1
+#define _POSIX_SPAWN_DUP2   2
+#define _POSIX_SPAWN_OPEN   3
+#define _POSIX_SPAWN_CHDIR  4
+#define _POSIX_SPAWN_FCHDIR 5
 
 #if !(__ASSEMBLER__ + __LINKER__ + 0)
 COSMOPOLITAN_C_START_
diff --git a/libc/proc/posix_spawn_file_actions_addchdir_np.c b/libc/proc/posix_spawn_file_actions_addchdir_np.c
new file mode 100644
index 000000000..94f40a832
--- /dev/null
+++ b/libc/proc/posix_spawn_file_actions_addchdir_np.c
@@ -0,0 +1,41 @@
+/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
+│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8                                :vi│
+╞══════════════════════════════════════════════════════════════════════════════╡
+│ Copyright 2023 Justine Alexandra Roberts Tunney                              │
+│                                                                              │
+│ Permission to use, copy, modify, and/or distribute this software for         │
+│ any purpose with or without fee is hereby granted, provided that the         │
+│ above copyright notice and this permission notice appear in all copies.      │
+│                                                                              │
+│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL                │
+│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED                │
+│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE             │
+│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL         │
+│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR        │
+│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER               │
+│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
+│ PERFORMANCE OF THIS SOFTWARE.                                                │
+╚─────────────────────────────────────────────────────────────────────────────*/
+#include "libc/errno.h"
+#include "libc/mem/mem.h"
+#include "libc/proc/posix_spawn.h"
+#include "libc/proc/posix_spawn.internal.h"
+
+/**
+ * Add chdir() action to spawn.
+ *
+ * @param file_actions was initialized by posix_spawn_file_actions_init()
+ * @param path will be safely copied
+ * @return 0 on success, or errno on error
+ * @raise ENOMEM if insufficient memory was available
+ */
+int posix_spawn_file_actions_addchdir_np(
+    posix_spawn_file_actions_t *file_actions, const char *path) {
+  char *path2;
+  if (!(path2 = strdup(path))) return ENOMEM;
+  return __posix_spawn_add_file_action(file_actions,
+                                       (struct _posix_faction){
+                                           .action = _POSIX_SPAWN_CHDIR,
+                                           .path = path2,
+                                       });
+}
diff --git a/libc/proc/posix_spawn_file_actions_addfchdir_np.c b/libc/proc/posix_spawn_file_actions_addfchdir_np.c
new file mode 100644
index 000000000..5e98e6cc9
--- /dev/null
+++ b/libc/proc/posix_spawn_file_actions_addfchdir_np.c
@@ -0,0 +1,39 @@
+/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
+│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8                                :vi│
+╞══════════════════════════════════════════════════════════════════════════════╡
+│ Copyright 2023 Justine Alexandra Roberts Tunney                              │
+│                                                                              │
+│ Permission to use, copy, modify, and/or distribute this software for         │
+│ any purpose with or without fee is hereby granted, provided that the         │
+│ above copyright notice and this permission notice appear in all copies.      │
+│                                                                              │
+│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL                │
+│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED                │
+│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE             │
+│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL         │
+│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR        │
+│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER               │
+│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
+│ PERFORMANCE OF THIS SOFTWARE.                                                │
+╚─────────────────────────────────────────────────────────────────────────────*/
+#include "libc/errno.h"
+#include "libc/proc/posix_spawn.h"
+#include "libc/proc/posix_spawn.internal.h"
+
+/**
+ * Add fchdir() action to spawn.
+ *
+ * @param path will be safely copied
+ * @return 0 on success, or errno on error
+ * @raise ENOMEM if insufficient memory was available
+ * @raise EBADF if `fildes` is negative
+ */
+int posix_spawn_file_actions_addfchdir_np(
+    posix_spawn_file_actions_t *file_actions, int fildes) {
+  if (fildes < 0) return EBADF;
+  return __posix_spawn_add_file_action(file_actions,
+                                       (struct _posix_faction){
+                                           .action = _POSIX_SPAWN_FCHDIR,
+                                           .fildes = fildes,
+                                       });
+}
diff --git a/libc/proc/posix_spawn_file_actions_addopen.c b/libc/proc/posix_spawn_file_actions_addopen.c
index 3f369489c..f84258195 100644
--- a/libc/proc/posix_spawn_file_actions_addopen.c
+++ b/libc/proc/posix_spawn_file_actions_addopen.c
@@ -29,16 +29,14 @@
  * @param fildes is what open() result gets duplicated to
  * @param path will be safely copied
  * @return 0 on success, or errno on error
- * @raise ENOMEM if we require more vespene gas
+ * @raise ENOMEM if insufficient memory was available
  * @raise EBADF if `fildes` is negative
- * @raise ENOTSUP if `fildes` isn't 0, 1, or 2 on Windows
  */
 int posix_spawn_file_actions_addopen(posix_spawn_file_actions_t *file_actions,
                                      int fildes, const char *path, int oflag,
                                      unsigned mode) {
   char *path2;
   if (fildes < 0) return EBADF;
-  if (IsWindows() && fildes > 2) return ENOTSUP;
   if (!(path2 = strdup(path))) return ENOMEM;
   return __posix_spawn_add_file_action(file_actions,
                                        (struct _posix_faction){
diff --git a/libc/thread/pthread_setname_np.c b/libc/thread/pthread_setname_np.c
index bf527bb1b..d28df7154 100644
--- a/libc/thread/pthread_setname_np.c
+++ b/libc/thread/pthread_setname_np.c
@@ -133,7 +133,7 @@ errno_t pthread_setname_np(pthread_t thread, const char *name) {
   BLOCK_CANCELATION;
   err = pthread_setname_impl(pt, name);
   ALLOW_CANCELATION;
-  STRACE("pthread_setname_np(%d, %s) → %s", _pthread_tid(pt), name,
+  STRACE("pthread_setname_np(%d, %#s) → %s", _pthread_tid(pt), name,
          DescribeErrno(err));
   return err;
 }
diff --git a/net/http/parsehttpmessage.c b/net/http/parsehttpmessage.c
index fd7490bee..aae0fe810 100644
--- a/net/http/parsehttpmessage.c
+++ b/net/http/parsehttpmessage.c
@@ -57,7 +57,7 @@ void DestroyHttpMessage(struct HttpMessage *r) {
  * This parser is responsible for determining the length of a message
  * and slicing the strings inside it. Performance is attained using
  * perfect hash tables. No memory allocation is performed for normal
- * messages. Line folding is forbidden. State persists across calls so
+ * messagesy. Line folding is forbidden. State persists across calls so
  * that fragmented messages can be handled efficiently. A limitation on
  * message size is imposed to make the header data structures smaller.
  *
diff --git a/test/libc/calls/pledge_test.c b/test/libc/calls/pledge_test.c
index 110f7acc5..0f0b07077 100644
--- a/test/libc/calls/pledge_test.c
+++ b/test/libc/calls/pledge_test.c
@@ -127,6 +127,12 @@ void *Enclave(void *arg) {
   return 0;                  // exit
 }
 
+TEST(pledge, tester) {
+  SPAWN(fork);
+  ASSERT_EQ(0, pledge("stdio rpath wpath cpath proc exec", NULL));
+  EXITS(0);
+}
+
 TEST(pledge, withThreadMemory) {
   if (IsOpenbsd()) return;  // openbsd doesn't allow it, wisely
   pthread_t worker;
diff --git a/test/libc/proc/posix_spawn_test.c b/test/libc/proc/posix_spawn_test.c
index 543620541..9a15daf4c 100644
--- a/test/libc/proc/posix_spawn_test.c
+++ b/test/libc/proc/posix_spawn_test.c
@@ -53,6 +53,7 @@
 #include "libc/testlib/ezbench.h"
 #include "libc/testlib/testlib.h"
 #include "libc/thread/thread.h"
+#include "libc/x/x.h"
 #include "third_party/nsync/mu.h"
 
 const char kTinyLinuxExit[128] = {
@@ -161,6 +162,29 @@ TEST(posix_spawn, pipe) {
   ASSERT_EQ(0, posix_spawn_file_actions_destroy(&fa));
 }
 
+TEST(posix_spawn, chdir) {
+  int ws, pid, p[2];
+  char buf[16] = {0};
+  char *args[] = {"cocmd.com", "-c", "cat hello.txt", 0};
+  char *envs[] = {0};
+  posix_spawn_file_actions_t fa;
+  testlib_extract("/zip/cocmd.com", "cocmd.com", 0755);
+  ASSERT_SYS(0, 0, mkdir("subdir", 0777));
+  ASSERT_SYS(0, 0, xbarf("subdir/hello.txt", "hello\n", -1));
+  ASSERT_SYS(0, 0, pipe2(p, O_CLOEXEC));
+  ASSERT_EQ(0, posix_spawn_file_actions_init(&fa));
+  ASSERT_EQ(0, posix_spawn_file_actions_adddup2(&fa, p[1], 1));
+  ASSERT_EQ(0, posix_spawn_file_actions_addchdir_np(&fa, "subdir"));
+  ASSERT_EQ(0, posix_spawn(&pid, "../cocmd.com", &fa, 0, args, envs));
+  ASSERT_EQ(0, posix_spawn_file_actions_destroy(&fa));
+  ASSERT_SYS(0, 0, close(p[1]));
+  ASSERT_NE(-1, waitpid(pid, &ws, 0));
+  ASSERT_EQ(0, ws);
+  ASSERT_SYS(0, 6, read(p[0], buf, sizeof(buf)));
+  ASSERT_STREQ("hello\n", buf);
+  ASSERT_SYS(0, 0, close(p[0]));
+}
+
 _Thread_local atomic_int gotsome;
 
 void OhMyGoth(int sig) {
diff --git a/test/libc/proc/test.mk b/test/libc/proc/test.mk
index e99cb528a..8bed04e07 100644
--- a/test/libc/proc/test.mk
+++ b/test/libc/proc/test.mk
@@ -64,6 +64,7 @@ o/$(MODE)/test/libc/proc/posix_spawn_test.com.dbg:		\
 		o/$(MODE)/test/libc/proc/posix_spawn_test.o	\
 		o/$(MODE)/test/libc/proc/proc.pkg		\
 		o/$(MODE)/tool/build/echo.com.zip.o		\
+		o/$(MODE)/tool/build/cocmd.com.zip.o		\
 		o/$(MODE)/test/libc/mem/prog/life.com.zip.o	\
 		o/$(MODE)/test/libc/mem/prog/life.elf.zip.o	\
 		o/$(MODE)/test/libc/proc/life-pe.com.zip.o	\