Make improvements

- Add rusage to redbean Lua API
- Add more redbean documentation
- Add pledge() to redbean Lua API
- Polyfill OpenBSD pledge() for Linux
- Increase PATH_MAX limit to 1024 characters
- Untrack sibling processes after fork() on Windows

libc/stdio/spawn.c

@@ -40,7 +40,7 @@ int posix_spawn(int *pid, const char *path,
   unsigned mode;
   sigset_t allsigs;
   struct sigaction dfl;
-  char *p, *q, opath[PATH_MAX + 1];
+  char *p, *q, opath[PATH_MAX];
   int s, fd, newfd, oflag, tempfd;
   if (!(*pid = vfork())) {
     if (attrp) {
@@ -77,7 +77,7 @@ int posix_spawn(int *pid, const char *path,
           if (sscanf(p + 5, "%d,", &fd) != 1) _Exit(127);
           p = strchr(p, ',') + 1;
           q = strchr(p, '*');
-          if (!q || q - p > PATH_MAX) _Exit(127);
+          if (!q || q - p >= PATH_MAX) _Exit(127);
           strncpy(opath, p, q - p);
           opath[q - p] = '\0';
           if (sscanf(q + 1, "%o,%o)", &oflag, &mode) != 2) _Exit(127);

libc/stdio/spawnp.c

@@ -31,7 +31,7 @@ int posix_spawnp(int *pid, const char *path,
                  const posix_spawn_file_actions_t *file_actions,
                  const posix_spawnattr_t *attrp, char *const argv[],
                  char *const envp[]) {
-  char pathbuf[PATH_MAX + 1];
+  char pathbuf[PATH_MAX];
   if (!(path = commandv(path, pathbuf, sizeof(pathbuf)))) return errno;
   return posix_spawn(pid, path, file_actions, attrp, argv, envp);
 }

libc/stdio/systemexec.c

@@ -18,6 +18,7 @@
 ╚─────────────────────────────────────────────────────────────────────────────*/
 #include "libc/calls/calls.h"
 #include "libc/dce.h"
+#include "libc/macros.internal.h"
 #include "libc/paths.h"
 #include "libc/runtime/runtime.h"
 #include "libc/str/str.h"
@@ -29,14 +30,16 @@
  */
 int systemexec(const char *cmdline) {
   size_t n, m;
-  char *a, *b, *argv[4], comspec[PATH_MAX + 1];
+  char *a, *b, *argv[4], comspec[PATH_MAX];
   if (!IsWindows()) {
     argv[0] = _PATH_BSHELL;
     argv[1] = "-c";
   } else {
     b = "cmd.exe";
     a = kNtSystemDirectory;
-    if ((n = strlen(a)) + (m = strlen(b)) > PATH_MAX) return enametoolong();
+    if ((n = strlen(a)) + (m = strlen(b)) >= ARRAYLEN(comspec)) {
+      return enametoolong();
+    }
     memcpy(mempcpy(comspec, a, n), b, m + 1);
     argv[0] = comspec;
     argv[1] = "/C";

libc/stdio/tmpfile.c

@@ -32,10 +32,10 @@
  */
 FILE *tmpfile(void) {
   int fd;
-  char *tmp, *sep, tpl[PATH_MAX + 1];
+  char *tmp, *sep, tpl[PATH_MAX];
   tmp = firstnonnull(getenv("TMPDIR"), kTmpPath);
   sep = !isempty(tmp) && !endswith(tmp, "/") ? "/" : "";
-  if ((snprintf)(tpl, PATH_MAX + 1, "%s%stmp.%s.XXXXXX", tmp, sep,
+  if ((snprintf)(tpl, PATH_MAX, "%s%stmp.%s.XXXXXX", tmp, sep,
                  program_invocation_short_name) <= PATH_MAX) {
     if ((fd = mkostemps(tpl, 0, 0)) != -1) {
       return fdopen(fd, "w+");