xref: /minix3/lib/libc/sys/utimes.2 (revision 84d9c625bfea59e274550651111ae9edfdc40fbd)
1.\"	$NetBSD: utimes.2,v 1.40 2013/10/05 21:24:36 ast Exp $
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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
67The access and modification times of the file named by
68.Fa path
69or referenced by
70.Fa fd
71are changed as specified by the argument
72.Fa times .
73.Pp
74If
75.Fa times
76is
77.Dv NULL ,
78the access and modification times are set to the current time.
79The caller must be the owner of the file, have permission to
80write the file, or be the super-user.
81.Pp
82If
83.Fa times
84is
85.Pf non- Dv NULL ,
86it is assumed to point to an array of two timeval structures.
87The access time is set to the value of the first element, and the
88modification time is set to the value of the second element.
89For file systems that support file birth (creation) times (such as
90UFS2), the birth time will be set to the value of the second element
91if the second element is older than the currently set birth time.
92To set both a birth time and a modification time, two calls are
93required; the first to set the birth time and the second to set
94the (presumably newer) modification time.
95Ideally a new system call will be added that allows the setting of
96all three times at once.
97The caller must be the owner of the file or be the super-user.
98.Pp
99In either case, the inode-change-time of the file is set to the current
100time.
101.Pp
102.Fn lutimes
103is like
104.Fn utimes
105except in the case where the named file is a symbolic link,
106in which case
107.Fn lutimes
108changes the access and modification times of the link,
109while
110.Fn utimes
111changes the times of the file the link references.
112.Pp
113.Fn utimens ,
114.Fn lutimens ,
115and
116.Fn futimens
117are like
118.Fn utimes ,
119.Fn lutimes ,
120and
121.Fn futimes
122respectively except that time is specified with nanosecond instead of
123microsecond precision.
124.Pp
125.Fn utimensat
126works the same way as
127.Fn utimens
128except if
129.Fa path
130is relative.
131In that case, it is looked up from a directory whose file
132descriptor was passed as
133.Fa fd .
134Search 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
147can be set to
148.Dv AT_FDCWD
149in order to specify the current directory.
150.Pp
151When it operates on a symbolic link,
152.Fn utimensat
153will change the target's time unless
154.Dv AT_SYMLINK_NOFOLLOW
155is set in
156.Fa flag .
157In that later case, the symbolic link's dates are changed.
158.Pp
159The nanosecond fields for
160.Fn utimens ,
161.Fn lutimens ,
162.Fn futimens ,
163and
164.Fn utimensat
165can be set to the special value
166.Dv UTIME_NOW
167to set the current time, or to
168.Dv UTIME_OMIT
169to let the time unchanged (this allows changing access time but not
170modification 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 ,
178and
179.Fn utimensat
180will fail if:
181.Bl -tag -width Er
182.It Bq Er EACCES
183Search permission is denied for a component of the path prefix;
184or the
185.Fa times
186argument is
187.Dv NULL
188and the effective user ID of the process does not
189match the owner of the file, and is not the super-user, and write
190access is denied.
191.It Bq Er EFAULT
192.Fa path
193or
194.Fa times
195points outside the process's allocated address space.
196.It Bq Er EIO
197An I/O error occurred while reading or writing the affected inode.
198.It Bq Er ELOOP
199Too many symbolic links were encountered in translating the pathname.
200.It Bq Er ENAMETOOLONG
201A component of a pathname exceeded
202.Brq Dv NAME_MAX
203characters, or an entire path name exceeded
204.Brq Dv PATH_MAX
205characters.
206.It Bq Er ENOENT
207The named file does not exist.
208.It Bq Er ENOTDIR
209A component of the path prefix is not a directory.
210.It Bq Er EPERM
211The
212.Fa times
213argument is not
214.Dv NULL
215and the calling process's effective user ID
216does not match the owner of the file and is not the super-user.
217.It Bq Er EROFS
218The file system containing the file is mounted read-only.
219.El
220.Pp
221In addition,
222.Fn utimensat
223will fail if:
224.Bl -tag -width Er
225.It Bq Er EBADF
226.Fa path
227does not specify an absolute path and
228.Fa fd
229is neither
230.Dv AT_FDCWD
231nor a valid file descriptor open for reading or searching.
232.It Bq Er ENOTDIR
233.Fa path
234is not an absolute path and
235.Fa fd
236is a file descriptor associated with a non-directory file.
237.El
238.Pp
239.Fn futimes
240and
241.Fn futimens
242will fail if:
243.Bl -tag -width Er
244.It Bq Er EACCES
245The
246.Fa times
247argument is
248.Dv NULL
249and the effective user ID of the process does not
250match the owner of the file, and is not the super-user, and write
251access is denied.
252.It Bq Er EBADF
253.Fa fd
254does not refer to a valid descriptor.
255.It Bq Er EFAULT
256.Fa times
257points outside the process's allocated address space.
258.It Bq Er EIO
259An I/O error occurred while reading or writing the affected inode.
260.It Bq Er EPERM
261The
262.Fa times
263argument is not
264.Dv NULL
265and the calling process's effective user ID
266does not match the owner of the file and is not the super-user.
267.It Bq Er EROFS
268The 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
275The
276.Fn utimes
277function conforms to
278.St -p1003.1-2001 .
279It was however marked as legacy in the
280.St -p1003.1-2004
281revision.
282.Fn futimens
283and
284.Fn utimensat
285functions conform to
286.St -p1003.1-2008 .
287.Sh HISTORY
288The
289.Fn utimes
290function call appeared in
291.Bx 4.2 .
292The
293.Fn futimes
294function call appeared in
295.Nx 1.2 .
296The
297.Fn lutimes
298function call appeared in
299.Nx 1.3 .
300Birthtime setting support was added in
301.Nx 5.0 .
302.Fn futimens
303and
304.Fn utimensat
305functions calls appeared in
306.Nx 6.0 .
307