table of contents
UTIMES(2) | System Calls Manual | UTIMES(2) |
NAME¶
utimes
, lutimes
,
futimes
, futimesat
—
LIBRARY¶
Standard C Library (libc, -lc)SYNOPSIS¶
#include <sys/time.h>
int
utimes
(const
char *path, const struct
timeval *times);
int
lutimes
(const
char *path, const struct
timeval *times);
int
futimes
(int
fd, const struct timeval
*times);
int
futimesat
(int
fd, const char
*path, const struct
timeval times[2]);
DESCRIPTION¶
The access and modification times of the file named by path or referenced by fd are changed as specified by the argument times.
If times is NULL
,
the access and modification times are set to the current time. The caller
must be the owner of the file, have permission to write the file, or be the
super-user.
If times is
non-NULL
, it is assumed to
point to an array of two timeval structures. The access time is set to the
value of the first element, and the modification time is set to the value of
the second element. For file systems that support file birth (creation)
times (such as UFS2
), the birth time will be set to
the value of the second element if the second element is older than the
currently set birth time. To set both a birth time and a modification time,
two calls are required; the first to set the birth time and the second to
set the (presumably newer) modification time. Ideally a new system call will
be added that allows the setting of all three times at once. The caller must
be the owner of the file or be the super-user.
In either case, the inode-change-time of the file is set to the current time.
The lutimes
() system call is like
utimes
() except in the case where the named file is
a symbolic link, in which case lutimes
() changes the
access and modification times of the link, while
utimes
() changes the times of the file the link
references.
The futimesat
() system call is equivalent
to utimes
() except in the case where
path specifies a relative path. In this case the
access and modification time is set to that of a file relative to the
directory associated with the file descriptor fd
instead of the current working directory. If
futimesat
() is passed the special value
AT_FDCWD
in the fd parameter,
the current working directory is used and the behavior is identical to a
call to utimes
().
RETURN VALUES¶
Upon successful completion, the value 0 is returned; otherwise the value -1 is returned and the global variable errno is set to indicate the error.ERRORS¶
All of the system call will fail if:- [
EACCES
] - Search permission is denied for a component of the path prefix.
- [
EACCES
] - The times argument is
NULL
and the effective user ID of the process does not match the owner of the file, and is not the super-user, and write access is denied. - [
EFAULT
] - The path or times argument points outside the process's allocated address space.
- [
EFAULT
] - The times argument points outside the process's allocated address space.
- [
EINVAL
] - The tv_usec component of at least one of the values specified by the times argument has a value less than 0 or greater than 999999.
- [
EIO
] - An I/O error occurred while reading or writing the affected inode.
- [
ELOOP
] - Too many symbolic links were encountered in translating the pathname.
- [
ENAMETOOLONG
] - A component of a pathname exceeded
NAME_MAX
characters, or an entire path name exceededPATH_MAX
characters. - [
ENOENT
] - The named file does not exist.
- [
ENOTDIR
] - A component of the path prefix is not a directory.
- [
EPERM
] - The times argument is not
NULL
and the calling process's effective user ID does not match the owner of the file and is not the super-user. - [
EPERM
] - The named file has its immutable or append-only flags set. See the chflags(2) manual page for more information.
- [
EROFS
] - The file system containing the file is mounted read-only.
The futimes
() system call will fail
if:
- [
EBADF
] - The fd argument does not refer to a valid descriptor.
In addition to the errors returned by the
utimes
(), the futimesat
()
may fail if:
SEE ALSO¶
chflags(2), stat(2), utimensat(2), utime(3)STANDARDS¶
Theutimes
() function is expected to conform to
X/Open Portability Guide Issue 4, Version 2
(“XPG4.2”). The futimesat
()
system call follows The Open Group Extended API Set 2 specification but was
replaced by utimensat
() in IEEE Std
1003.1-2008 (“POSIX.1”).
HISTORY¶
Theutimes
() system call appeared in
4.2BSD. The futimes
() and
lutimes
() system calls first appeared in
FreeBSD 3.0. The futimesat
()
system call appeared in FreeBSD 8.0.
June 9, 2016 | Linux 4.9.0-9-amd64 |