3 walk \- descend a directory hierarchy
12 .IR nwname *( wname [ s ])
18 .IR nwqid *( qid [13])
22 request carries as arguments an existing
26 (which must not be in use unless it is the same as
28 that the client wishes to associate with
29 the result of traversing the directory hierarchy
30 by `walking' the hierarchy using the successive path name
35 must represent a directory unless zero path name elements are specified.
39 must be valid in the current session and must not have been opened for I/O
45 If the full sequence of
47 elements is walked successfully,
49 will represent the file that results.
57 is in use or otherwise illegal, an
63 (dot-dot) represents the parent directory.
66 (dot), meaning the current directory, is not used in the protocol.
70 to be zero, in which case
72 will represent the same file as
76 will usually succeed; this is equivalent to walking to dot.
77 The rest of this discussion assumes
85 are walked in order, ``elementwise''.
86 For the first elementwise walk
87 to succeed, the file identified by
90 and the implied user of the request must have permission
91 to search the directory (see
93 Subsequent elementwise walks have equivalent restrictions
94 applied to the implicit fid that results from the preceding elementwise walk.
96 If the first element cannot be walked for any reason,
99 Otherwise, the walk will return an
103 qids corresponding, in order, to the files that are visited by the
105 successful elementwise walks;
109 or the index of the first elementwise walk that failed.
112 cannot be zero unless
117 will always be less than or equal to
119 Only if it is equal, however, will
121 be affected, in which case
123 will represent the file
124 reached by the final elementwise walk requested in the message.
130 in the root directory of a server is equivalent to a walk with no name elements.
136 the above discussion applies, with the obvious difference
137 that if the walk changes the state of
139 it also changes the state of
147 To simplify the implementation of the servers, a maximum of sixteen name elements or qids
148 may be packed in a single message.
149 This constant is called
153 Despite this restriction, the system imposes no limit on the number of elements in a file name,
154 only the number that may be transmitted in a single message.
159 generates walk messages.
160 One or more walk messages may be generated by
161 any call that evaluates file names:
173 .\" messages may be generated by
174 .\" any of the following calls, which evaluate file names:
184 .\" The file name element
186 .\" (dot) is interpreted locally and
187 .\" is not transmitted in
