utimeslutimesfutimes
- set file access and modification times
LIBRARY
Lb libc
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);
DESCRIPTION
The access and modification times of the file named by
Fa path
or referenced by
Fa fd
are changed as specified by the argument
Fa times .
If
Fa 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
Fa 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.
RETURN VALUES
Rv -std
ERRORS
The
utimes ();
and
lutimes ();
system calls
will fail if:
Bq Er EACCES
Search permission is denied for a component of the path prefix;
or the
Fa 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.
Bq Er EFAULT
The
Fa path
or
Fa times
argument
points outside the process's allocated address space.
Bq Er EIO
An I/O error occurred while reading or writing the affected inode.
Bq Er ELOOP
Too many symbolic links were encountered in translating the pathname.
Bq Er ENAMETOOLONG
A component of a pathname exceeded
NAME_MAX
characters, or an entire path name exceeded
PATH_MAX
characters.
Bq Er ENOENT
The named file does not exist.
Bq Er ENOTDIR
A component of the path prefix is not a directory.
Bq Er EPERM
The
Fa 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.
Bq Er EPERM
The named file has its immutable or append-only flag set, see the
chflags(2)
manual page for more information.
Bq Er EROFS
The file system containing the file is mounted read-only.
The
futimes ();
system call
will fail if:
Bq Er EBADF
The
Fa fd
argument
does not refer to a valid descriptor.
All of the system calls will fail if:
Bq Er EACCES
The
Fa 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.
Bq Er EFAULT
The
Fa times
argument
points outside the process's allocated address space.
Bq Er EINVAL
The
tv_usec
component of at least one of the values specified by the
Fa times
argument has a value less than 0 or greater than 999999.
Bq Er EIO
An I/O error occurred while reading or writing the affected inode.
Bq Er EPERM
The
Fa 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.
Bq Er EROFS
The file system containing the file is mounted read-only.
