af_histories, af_access - AtFS history functions
char**af_histories (char *path, char *pattern)
char**af_cachenames (char *path, char *pattern);
int af_access (char *path, char *name, char *type, int mode)
af_histories returns a list of source history names from the directory
pointed to by path, that match the given pattern. Histories in a
directory are represented by at least one version. The pattern must be
ed(1) patterns, processable by re_comp(3) and re_exec(3). The resulting
list of af_histories resides in allocated memory. Use free(3) to free
the memory for further allocation. af_histories returns an empty list
(not a NULL pointer !), when no histories are found.
af_cachenames does the same as af_histories but on derived object
af_access determines the existence of an object history. If any ASO
(any version) with the given path, name and type attributes exists,
af_access returns zero, otherwise -1. The mode argument can either be
indicating that only source objects shall be searched or
which means that only the derived object cache shall be
searched for existence of a matching ASO.
ed(1), re_comp(3), re_exec(3), free(3)
Upon error, -1 or a null pointer (depending on the return type) is
returned and af_errno is set to the corresponding error number.