Move generic fs helpers to os/include/file_system

Fixes #1488

repos/os/include/file_system/util.h

@@ -0,0 +1,63 @@
+/*
+ * \brief  Utilities
+ * \author Norman Feske
+ * \date   2012-04-11
+ */
+
+#ifndef _FILE_SYSTEM__UTIL_H_
+#define _FILE_SYSTEM__UTIL_H_
+
+/**
+ * Return base-name portion of null-terminated path string
+ */
+static inline char const *basename(char const *path)
+{
+	char const *start = path;
+
+	for (; *path; path++)
+		if (*path == '/')
+			start = path + 1;
+
+	return start;
+}
+
+
+/**
+ * Return true if specified path is a base name (contains no path delimiters)
+ */
+static inline bool is_basename(char const *path)
+{
+	for (; *path; path++)
+		if (*path == '/')
+			return false;
+
+	return true;
+}
+
+
+/**
+ * Return true if character 'c' occurs in null-terminated string 'str'
+ */
+static inline bool string_contains(char const *str, char c)
+{
+	for (; *str; str++)
+		if (*str == c)
+			return true;
+	return false;
+}
+
+
+/**
+ * Return true if 'str' is a valid node name
+ */
+static inline bool valid_name(char const *str)
+{
+	if (string_contains(str, '/')) return false;
+
+	/* must have at least one character */
+	if (str[0] == 0) return false;
+
+	return true;
+}
+
+#endif /* _FILE_SYSTEM__UTIL_H_ */