feat(passwd): getpw*/getgr*/setpwent/endpwent family

include/stdlib.h

@@ -544,6 +544,21 @@ getsubopt(char **optionp, char *const *tokens, char **valuep);
 
 #endif /* VLIBC_LEVEL_GE(2) */
 
+#if VLIBC_LEVEL_GE(2)
+
+/*
+ * Resolve path to an absolute, NUL-terminated canonical pathname with no
+ * symbolic links, "." or ".." components (todo 38). resolved_path may be
+ * NULL, in which case the canonical path is returned in a malloc'd
+ * buffer the caller must free; otherwise it must hold at least PATH_MAX
+ * bytes. Returns resolved_path (or the malloc'd buffer), or NULL with
+ * errno set. XSI.
+ */
+char *
+realpath(const char *restrict path, char *restrict resolved_path);
+
+#endif /* VLIBC_LEVEL_GE(2) */
+
 #ifdef __cplusplus
 }
 #endif