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UTIMES(2) | System Calls Manual | UTIMES(2) |
NAME¶
utimes
,
lutimes
,
futimes
,
futimesat
—
set file access and modification times
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 isNULL
, 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.
futimes
() system call will fail if:
- [
EBADF
] - The fd argument does not refer to a valid descriptor.
utimes
(), the
futimesat
() may fail if:
- [
EBADF
] - The path argument does not specify an
absolute path and the fd argument is
neither
AT_FDCWD
nor a valid file descriptor open for searching. - [
ENOTDIR
] - The path argument is not an absolute path
and fd is neither
AT_FDCWD
nor a file descriptor associated with a directory.
SEE ALSO¶
chflags(2), stat(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.
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.July 3, 2014 | Debian |