+/**
+ * Same as above, but takes in a file name instead of fd
+ */
+template <class Container>
+bool readFile(
+ const char* file_name,
+ Container& out,
+ size_t num_bytes = std::numeric_limits<size_t>::max()) {
+ DCHECK(file_name);
+
+ const auto fd = openNoInt(file_name, O_RDONLY);
+ if (fd == -1) {
+ return false;
+ }
+
+ SCOPE_EXIT {
+ // Ignore errors when closing the file
+ closeNoInt(fd);
+ };
+
+ return readFile(fd, out, num_bytes);
+}
+
+/**
+ * Writes container to file. The container is assumed to be
+ * contiguous, with element size equal to 1, and offering STL-like
+ * methods empty(), size(), and indexed access
+ * (e.g. std::vector<char>, std::string, fbstring, StringPiece).
+ *
+ * "flags" dictates the open flags to use. Default is to create file
+ * if it doesn't exist and truncate it.
+ *
+ * Returns: true on success or false on failure. In the latter case
+ * errno will be set appropriately by the failing system primitive.
+ *
+ * Note that this function may leave the file in a partially written state on
+ * failure. Use writeFileAtomic() if you want to ensure that the existing file
+ * state will be unchanged on error.
+ */
+template <class Container>
+bool writeFile(const Container& data, const char* filename,
+ int flags = O_WRONLY | O_CREAT | O_TRUNC) {
+ static_assert(sizeof(data[0]) == 1,
+ "writeFile works with element size equal to 1");
+ int fd = open(filename, flags, 0666);
+ if (fd == -1) {
+ return false;
+ }
+ bool ok = data.empty() ||
+ writeFull(fd, &data[0], data.size()) == static_cast<ssize_t>(data.size());
+ return closeNoInt(fd) == 0 && ok;
+}