| blob | af21899871a9e2056a9db9ced07609e4287de386 |
1 .\" $NetBSD: utimes.2,v 1.40 2013/10/05 21:24:36 ast Exp $
2 .\"
3 .\" Copyright (c) 1990, 1993
4 .\" The Regents of the University of California. All rights reserved.
5 .\"
6 .\" Redistribution and use in source and binary forms, with or without
7 .\" modification, are permitted provided that the following conditions
8 .\" are met:
9 .\" 1. Redistributions of source code must retain the above copyright
10 .\" notice, this list of conditions and the following disclaimer.
11 .\" 2. Redistributions in binary form must reproduce the above copyright
12 .\" notice, this list of conditions and the following disclaimer in the
13 .\" documentation and/or other materials provided with the distribution.
14 .\" 3. Neither the name of the University nor the names of its contributors
15 .\" may be used to endorse or promote products derived from this software
16 .\" without specific prior written permission.
17 .\"
18 .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
19 .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
22 .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 .\" SUCH DAMAGE.
29 .\"
30 .\" @(#)utimes.2 8.1 (Berkeley) 6/4/93
31 .\"
32 .Dd September 14, 2013
33 .Dt UTIMES 2
34 .Os
35 .Sh NAME
36 .Nm utimes ,
37 .Nm lutimes ,
38 .Nm futimes ,
39 .Nm utimens ,
40 .Nm lutimens ,
41 .Nm futimens ,
42 .Nm utimensat
43 .Nd set file access and modification times
44 .Sh LIBRARY
45 .Lb libc
46 .Sh SYNOPSIS
47 .In sys/time.h
48 .Ft int
49 .Fn utimes "const char *path" "const struct timeval times[2]"
50 .Ft int
51 .Fn lutimes "const char *path" "const struct timeval times[2]"
52 .Ft int
53 .Fn futimes "int fd" "const struct timeval times[2]"
54 .In sys/stat.h
55 .Ft int
56 .Fn utimens "const char *path" "const struct timespec times[2]"
57 .Ft int
58 .Fn lutimens "const char *path" "const struct timespec times[2]"
59 .Ft int
60 .Fn futimens "int fd" "const struct timespec times[2]"
61 .In sys/stat.h
62 .In fcntl.h
63 .Ft int
64 .Fn utimensat "int fd" "const char *path" "const struct timespec times[2]" \
65 "int flag"
66 .Sh DESCRIPTION
67 The access and modification times of the file named by
68 .Fa path
69 or referenced by
70 .Fa fd
71 are changed as specified by the argument
72 .Fa times .
73 .Pp
74 If
75 .Fa times
76 is
77 .Dv NULL ,
78 the access and modification times are set to the current time.
79 The caller must be the owner of the file, have permission to
80 write the file, or be the super-user.
81 .Pp
82 If
83 .Fa times
84 is
85 .Pf non- Dv NULL ,
86 it is assumed to point to an array of two timeval structures.
87 The access time is set to the value of the first element, and the
88 modification time is set to the value of the second element.
89 For file systems that support file birth (creation) times (such as
90 UFS2), the birth time will be set to the value of the second element
91 if the second element is older than the currently set birth time.
92 To set both a birth time and a modification time, two calls are
93 required; the first to set the birth time and the second to set
94 the (presumably newer) modification time.
95 Ideally a new system call will be added that allows the setting of
96 all three times at once.
97 The caller must be the owner of the file or be the super-user.
98 .Pp
99 In either case, the inode-change-time of the file is set to the current
100 time.
101 .Pp
102 .Fn lutimes
103 is like
104 .Fn utimes
105 except in the case where the named file is a symbolic link,
106 in which case
107 .Fn lutimes
108 changes the access and modification times of the link,
109 while
110 .Fn utimes
111 changes the times of the file the link references.
112 .Pp
113 .Fn utimens ,
114 .Fn lutimens ,
115 and
116 .Fn futimens
117 are like
118 .Fn utimes ,
119 .Fn lutimes ,
120 and
121 .Fn futimes
122 respectively except that time is specified with nanosecond instead of
123 microsecond precision.
124 .Pp
125 .Fn utimensat
126 works the same way as
127 .Fn utimens
128 except if
129 .Fa path
130 is relative.
131 In that case, it is looked up from a directory whose file
132 descriptor was passed as
133 .Fa fd .
134 Search permission is required on this directory.
135 .\" (These alternatives await a decision about the semantics of O_SEARCH)
136 .\" Search permission is required on this directory
137 .\" except if
138 .\" .Fa fd
139 .\" was opened with the
140 .\" .Dv O_SEARCH
141 .\" flag.
142 .\" - or -
143 .\" This file descriptor must have been opened with the
144 .\" .Dv O_SEARCH
145 .\" flag.
146 .Fa fd
147 can be set to
148 .Dv AT_FDCWD
149 in order to specify the current directory.
150 .Pp
151 When it operates on a symbolic link,
152 .Fn utimensat
153 will change the target's time unless
154 .Dv AT_SYMLINK_NOFOLLOW
155 is set in
156 .Fa flag .
157 In that later case, the symbolic link's dates are changed.
158 .Pp
159 The nanosecond fields for
160 .Fn utimens ,
161 .Fn lutimens ,
162 .Fn futimens ,
163 and
164 .Fn utimensat
165 can be set to the special value
166 .Dv UTIME_NOW
167 to set the current time, or to
168 .Dv UTIME_OMIT
169 to let the time unchanged (this allows changing access time but not
170 modification time, and vice-versa).
171 .Sh RETURN VALUES
172 .Rv -std utimes lutimes futimes utimens lutimens futimens utimensat
173 .Sh ERRORS
174 .Fn utimes ,
175 .Fn lutimes ,
176 .Fn utimens ,
177 .Fn lutimens ,
178 and
179 .Fn utimensat
180 will fail if:
181 .Bl -tag -width Er
182 .It Bq Er EACCES
183 Search permission is denied for a component of the path prefix;
184 or the
185 .Fa times
186 argument is
187 .Dv NULL
188 and the effective user ID of the process does not
189 match the owner of the file, and is not the super-user, and write
190 access is denied.
191 .It Bq Er EFAULT
192 .Fa path
193 or
194 .Fa times
195 points outside the process's allocated address space.
196 .It Bq Er EIO
197 An I/O error occurred while reading or writing the affected inode.
198 .It Bq Er ELOOP
199 Too many symbolic links were encountered in translating the pathname.
200 .It Bq Er ENAMETOOLONG
201 A component of a pathname exceeded
202 .Brq Dv NAME_MAX
203 characters, or an entire path name exceeded
204 .Brq Dv PATH_MAX
205 characters.
206 .It Bq Er ENOENT
207 The named file does not exist.
208 .It Bq Er ENOTDIR
209 A component of the path prefix is not a directory.
210 .It Bq Er EPERM
211 The
212 .Fa times
213 argument is not
214 .Dv NULL
215 and the calling process's effective user ID
216 does not match the owner of the file and is not the super-user.
217 .It Bq Er EROFS
218 The file system containing the file is mounted read-only.
219 .El
220 .Pp
221 In addition,
222 .Fn utimensat
223 will fail if:
224 .Bl -tag -width Er
225 .It Bq Er EBADF
226 .Fa path
227 does not specify an absolute path and
228 .Fa fd
229 is neither
230 .Dv AT_FDCWD
231 nor a valid file descriptor open for reading or searching.
232 .It Bq Er ENOTDIR
233 .Fa path
234 is not an absolute path and
235 .Fa fd
236 is a file descriptor associated with a non-directory file.
237 .El
238 .Pp
239 .Fn futimes
240 and
241 .Fn futimens
242 will fail if:
243 .Bl -tag -width Er
244 .It Bq Er EACCES
245 The
246 .Fa times
247 argument is
248 .Dv NULL
249 and the effective user ID of the process does not
250 match the owner of the file, and is not the super-user, and write
251 access is denied.
252 .It Bq Er EBADF
253 .Fa fd
254 does not refer to a valid descriptor.
255 .It Bq Er EFAULT
256 .Fa times
257 points outside the process's allocated address space.
258 .It Bq Er EIO
259 An I/O error occurred while reading or writing the affected inode.
260 .It Bq Er EPERM
261 The
262 .Fa times
263 argument is not
264 .Dv NULL
265 and the calling process's effective user ID
266 does not match the owner of the file and is not the super-user.
267 .It Bq Er EROFS
268 The file system containing the file is mounted read-only.
269 .El
270 .Sh SEE ALSO
271 .Xr stat 2 ,
272 .Xr utime 3 ,
273 .Xr symlink 7
274 .Sh STANDARDS
275 The
276 .Fn utimes
277 function conforms to
278 .St -p1003.1-2001 .
279 It was however marked as legacy in the
280 .St -p1003.1-2004
281 revision.
282 .Fn futimens
283 and
284 .Fn utimensat
285 functions conform to
286 .St -p1003.1-2008 .
287 .Sh HISTORY
288 The
289 .Fn utimes
290 function call appeared in
291 .Bx 4.2 .
292 The
293 .Fn futimes
294 function call appeared in
295 .Nx 1.2 .
296 The
297 .Fn lutimes
298 function call appeared in
299 .Nx 1.3 .
300 Birthtime setting support was added in
301 .Nx 5.0 .
302 .Fn futimens
303 and
304 .Fn utimensat
305 functions calls appeared in
306 .Nx 6.0 .