+
+ default:
+ return -1;
+ }
+}
+
+/* Returns the integer value of the 'n' hexadecimal digits starting at 's', or
+ * UINT_MAX if one of those "digits" is not really a hex digit. If 'ok' is
+ * nonnull, '*ok' is set to true if the conversion succeeds or to false if a
+ * non-hex digit is detected. */
+unsigned int
+hexits_value(const char *s, size_t n, bool *ok)
+{
+ unsigned int value;
+ size_t i;
+
+ value = 0;
+ for (i = 0; i < n; i++) {
+ int hexit = hexit_value(s[i]);
+ if (hexit < 0) {
+ if (ok) {
+ *ok = false;
+ }
+ return UINT_MAX;
+ }
+ value = (value << 4) + hexit;
+ }
+ if (ok) {
+ *ok = true;
+ }
+ return value;
+}
+
+/* Returns the current working directory as a malloc()'d string, or a null
+ * pointer if the current working directory cannot be determined. */
+char *
+get_cwd(void)
+{
+ long int path_max;
+ size_t size;
+
+ /* Get maximum path length or at least a reasonable estimate. */
+ path_max = pathconf(".", _PC_PATH_MAX);
+ size = (path_max < 0 ? 1024
+ : path_max > 10240 ? 10240
+ : path_max);
+
+ /* Get current working directory. */
+ for (;;) {
+ char *buf = xmalloc(size);
+ if (getcwd(buf, size)) {
+ return xrealloc(buf, strlen(buf) + 1);
+ } else {
+ int error = errno;
+ free(buf);
+ if (error != ERANGE) {
+ VLOG_WARN("getcwd failed (%s)", strerror(error));
+ return NULL;
+ }
+ size *= 2;
+ }
+ }
+}
+
+static char *
+all_slashes_name(const char *s)
+{
+ return xstrdup(s[0] == '/' && s[1] == '/' && s[2] != '/' ? "//"
+ : s[0] == '/' ? "/"
+ : ".");
+}
+
+/* Returns the directory name portion of 'file_name' as a malloc()'d string,
+ * similar to the POSIX dirname() function but thread-safe. */
+char *
+dir_name(const char *file_name)
+{
+ size_t len = strlen(file_name);
+ while (len > 0 && file_name[len - 1] == '/') {
+ len--;
+ }
+ while (len > 0 && file_name[len - 1] != '/') {
+ len--;