《通链参考手册》


19.2.2.4.3 Restrictions on Examining a Pathname Directory Component

The directory might be a string, :wild, :unspecific, or nil.

The directory can be a list of strings and symbols. The car of the list is one of the symbols :absolute or :relative, meaning:

Each remaining element of the list is a string or a symbol.

Each string names a single level of directory structure. The strings should contain only the directory names themselves---no punctuation characters.

In place of a string, at any point in the list, symbols can occur to indicate special file notations. The next figure lists the symbols that have standard meanings. Implementations are permitted to add additional objects of any type that is disjoint from string if necessary to represent features of their file systems that cannot be represented with the standard strings and symbols.

Supplying any non-string, including any of the symbols listed below, to a file system for which it does not make sense signals an error of type file-error. For example, Unix does not support :wild-inferiors in most implementations.

Symbol           Meaning                                             
:wild            Wildcard match of one level of directory structure  
:wild-inferiors  Wildcard match of any number of directory levels    
:up              Go upward in directory structure (semantic)         
:back            Go upward in directory structure (syntactic)        

■图表 19-3. Special Markers In Directory Component

The following notes apply to the previous figure:

19.2.2.4.3.1 Directory Components in Non-Hierarchical File Systems


X3J13设计清单非标准部分,可查下面章节:


◇首页 § ◎章节目录 § □内容索引 § ○符号索引 § △术语表 § ※设计草案