System Calls futimens(2)
NAME
futimens, utimensat - set file access and modification times
SYNOPSIS
#include
int futimens(int fd, const struct timespec times[2]);int utimensat(int fd, const char *path,
const struct timespec times[2], int flag);DESCRIPTION
The futimens() and utimensat() functions set the access and
modification times of a file to the values of the times argument. The futimens() function changes the times of thefile associated with the file descriptor fd. The utimensat()
function changes the times of the file pointed to by the path argument, relative to the directory associated with the file descriptor fd. Both functions allow time specifications accurate to the nanosecond. The times argument is an array of two timespec structures. The first array member represents the date and time of last access, and the second member represents the date and time of last modification. The times in the timespec structure are measured in seconds and nanoseconds since the Epoch. Thefile's relevant timestamp is set to the greatest value sup-
ported by the file system that is not greater than the specified time.If the tv_nsec field of a timespec structure has the special
value UTIME_NOW, the file's relevant timestamp is set to the
greatest value supported by the file system that is notgreater than the current time. If the tv_nsec field has the
special value UTIME_OMIT, the file's relevant timestamp is
not changed. In either case, the tv_sec field is ignored.
If the times argument is a null pointer, both the access andmodification timestamps are set to the greatest value sup-
ported by the file system that is not greater than thecurrent time. If utimensat() is passed a relative path in
the path argument, the file to be used is relative to the directory associated with the file descriptor fd instead of the current working directory.SunOS 5.11 Last change: 1 Sep 2009 1
System Calls futimens(2)If utimensat() is passed the special value AT_FDCWD in the
fd parameter, the current working directory is used. Only a process with the effective user ID equal to the user ID of the file, or with write access to the file, or withappropriate privileges may use futimens() or utimensat()
with a null pointer as the times argument or with bothtv_nsec fields set to the special value UTIME_NOW. Only a
process with the effective user ID equal to the user ID of the file or with appropriate privileges may use futimens()or utimensat() with a non-null times argument that does not
have both tv_nsec fields set to UTIME_NOW and does not have
both tv_nsec fields set to UTIME_OMIT. If both tv_nsec
fields are set to UTIME_OMIT, no ownership or permissions
check is performed for the file, but other error conditions are still detected (including EACCES errors related to the path prefix).Values for the flag argument of utimensat() are constructed
by a bitwise-inclusive OR of flags from the following list,
defined in: AT_SYMLINK_NOFOLLOW
If path names a symbolic link, then the access and modification times of the symbolic link are changed.Upon completion, futimens() and utimensat() mark the last
file status change timestamp for update.RETURN VALUES
Upon successful completion, these functions return 0. Other-
wise, these functions return -1 and set errno to indicate
the error. If -1 is returned, the file times are not
affected.ERRORS
The futimens() and utimensat() functions will fail if:
EACCES The times argument is a null pointer, or bothtv_nsec values are UTIME_NOW, and the effective
user ID of the process does not match the owner of the file and write access is denied. EINVAL Either of the times argument structures specifieda tv_nsec value that was neither UTIME_NOW nor
UTIME_OMIT, and was a value less than zero or
SunOS 5.11 Last change: 1 Sep 2009 2
System Calls futimens(2) greater than or equal to 1000 million.A new file timestamp would be a value whose tv_sec
component is not a value supported by the file system. EPERM The times argument is not a null pointer, does nothave both tv_nsec fields set to UTIME_NOW, does
not have both tv_nsec fields set to UTIME_OMIT,
the calling process' effective user ID has write access to the file but does not match the owner of the file, and the calling process does not have appropriate privileges.EROFS The file system containing the file is read-only.
The futimens() function will fail if: EBADF The fd argument is not a valid file descriptor.The utimensat() function will fail if:
EACCES The permissions of the directory underlying fd do not permit directory searches.EBADF The path argument does not specify an abso-
lute path and the fd argument is neitherAT_FDCWD nor a valid file descriptor open
for reading. ENOTDIR The path argument is not an absolute pathand fd is neither AT_FDCWD nor a file
descriptor associated with a directory. EACCES Search permission is denied by a component of the path prefix. ELOOP Too many symbolic links were encountered during resolution of the path argument.SunOS 5.11 Last change: 1 Sep 2009 3
System Calls futimens(2)ENAMETOOLONG The length of the path argument exceeds
{PATH_MAX} or a pathname component is longer
than {NAME_MAX}.
ENOENT A component of path does not name an exist-
ing file or path is an empty string. ENOTDIR A component of the path prefix is not a directory, or the path argument contains at least one character that is not a slash (/) and ends with one or more trailing slash characters and the last pathname component names an existing file that is neither adirectory nor a symbolic link to a direc-
tory.The utimensat() function will fail if:
ENAMETOOLONG Path name resolution of a symbolic link pro-
duced an intermediate result with a lengththat exceeds {PATH_MAX}.
ATTRIBUTES
See attributes(5) for descriptions of the following attri-
butes:____________________________________________________________
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
|_____________________________|_____________________________|
| Interface Stability | Committed ||_____________________________|_____________________________|
| MT-Level | Async-Signal-Safe |
|_____________________________|_____________________________|
SEE ALSO
stat(2), utime(2), utimes(2), attributes(5), fsattr(5)SunOS 5.11 Last change: 1 Sep 2009 4