Further improve cocmd interpreter

libc/calls/makedirs.c

@@ -0,0 +1,91 @@
+/*-*- 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 2021 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/calls/calls.h"
+#include "libc/calls/struct/stat.h"
+#include "libc/errno.h"
+#include "libc/str/path.h"
+#include "libc/str/str.h"
+#include "libc/sysv/consts/s.h"
+#include "libc/sysv/errfuns.h"
+
+/**
+ * Creates directory and parent components.
+ *
+ * This function is similar to mkdir() except it iteratively creates
+ * parent directories and it won't fail if the directory already exists.
+ *
+ * @param path is a UTF-8 string, preferably relative w/ forward slashes
+ * @param mode can be, for example, 0755
+ * @return 0 on success or -1 w/ errno
+ * @raise EEXIST if named file already exists as non-directory
+ * @raise ENOTDIR if directory component in `path` existed as non-directory
+ * @raise ENAMETOOLONG if symlink-resolved `path` length exceeds `PATH_MAX`
+ * @raise ENAMETOOLONG if component in `path` exists longer than `NAME_MAX`
+ * @raise EROFS if parent directory is on read-only filesystem
+ * @raise ENOSPC if file system or parent directory is full
+ * @raise EACCES if write permission was denied on parent directory
+ * @raise EACCES if search permission was denied on component in `path`
+ * @raise ENOENT if `path` is an empty string
+ * @raise ELOOP if loop was detected resolving components of `path`
+ * @asyncsignalsafe
+ * @threadsafe
+ */
+int makedirs(const char *path, unsigned mode) {
+  int c, e, i, n;
+  struct stat st;
+  char buf[PATH_MAX];
+
+  e = errno;
+  n = strlen(path);
+  if (n >= PATH_MAX) return enametoolong();
+  memcpy(buf, path, n + 1);
+  i = n;
+
+  // descend
+  while (i) {
+    if (!mkdir(buf, mode)) break;
+    if (errno == EEXIST) {
+      if (i == n) goto CheckTop;
+      break;
+    }
+    if (errno != ENOENT) return -1;
+    while (i && _isdirsep(buf[i - 1])) buf[--i] = 0;
+    while (i && !_isdirsep(buf[i - 1])) buf[--i] = 0;
+  }
+
+  // ascend
+  for (;;) {
+    if (mkdir(buf, mode)) {
+      if (errno != EEXIST) return -1;
+      if (i == n) goto CheckTop;
+    }
+    if (i == n) break;
+    while (i < n && !_isdirsep((c = path[i]))) buf[i++] = c;
+    while (i < n && _isdirsep((c = path[i]))) buf[i++] = c;
+  }
+
+Finish:
+  errno = e;
+  return 0;
+
+CheckTop:
+  if (stat(path, &st)) return -1;
+  if (S_ISDIR(st.st_mode)) goto Finish;
+  return eexist();
+}