Make improvements

- Expand redbean UNIX module
- Expand redbean documentation
- Ensure Lua copyright is embedded in binary
- Increase the PATH_MAX limit especially on NT
- Use column major sorting for linenoise completions
- Fix some suboptimalities in redbean's new UNIX API
- Figured out right flags for Multics newline in raw mode

libc/stdio/printf.c

@@ -32,10 +32,6 @@
  * - `%m` inserts strerror(errno) into the formatted output. This is
  *   consistent with glibc, musl, and uclibc.
  *
- * - `%n` inserts "\n" on non-Windows and "\r\n" on Windows. This is the
- *   same behavior as Java. It's incompatible with glibc's behavior,
- *   since that's problematic according to Android's security team.
- *
  * - `%hs` converts UTF-16/UCS-2 → UTF-8, which can be helpful on Windows.
  *   Formatting (e.g. %-10hs) will use monospace display width rather
  *   than string length or codepoint count.

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];
+  char *p, *q, opath[PATH_MAX + 1];
   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 + 1 > 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];
-  if (!(path = commandv(path, pathbuf))) return errno;
+  char pathbuf[PATH_MAX + 1];
+  if (!(path = commandv(path, pathbuf, sizeof(pathbuf)))) return errno;
   return posix_spawn(pid, path, file_actions, attrp, argv, envp);
 }

libc/stdio/tmpfile.c

@@ -32,11 +32,11 @@
  */
 FILE *tmpfile(void) {
   int fd;
-  char *tmp, *sep, tpl[PATH_MAX];
+  char *tmp, *sep, tpl[PATH_MAX + 1];
   tmp = firstnonnull(getenv("TMPDIR"), kTmpPath);
   sep = !isempty(tmp) && !endswith(tmp, "/") ? "/" : "";
-  if ((snprintf)(tpl, PATH_MAX, "%s%stmp.%s.XXXXXX", tmp, sep,
-                 program_invocation_short_name) < PATH_MAX) {
+  if ((snprintf)(tpl, PATH_MAX + 1, "%s%stmp.%s.XXXXXX", tmp, sep,
+                 program_invocation_short_name) <= PATH_MAX) {
     if ((fd = mkostemps(tpl, 0, 0)) != -1) {
       return fdopen(fd, "w+");
     }