man futimes (2): set file access and modification times

Other Alias

utimes, lutimes, futimesat

LIBRARY

Lb libc

SYNOPSIS

In sys/time.h Ft int Fn utimes const char *path const struct timeval *times Ft int Fn lutimes const char *path const struct timeval *times Ft int Fn futimes int fd const struct timeval *times Ft int Fn futimesat int fd const char *path const struct timeval times[2]

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 Fn lutimes system call is like Fn utimes except in the case where the named file is a symbolic link, in which case Fn lutimes changes the access and modification times of the link, while Fn utimes changes the times of the file the link references.

The Fn futimesat system call is equivalent to Fn utimes except in the case where Fa 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 Fa fd instead of the current working directory. If Fn futimesat is passed the special value AT_FDCWD in the Fa fd parameter, the current working directory is used and the behavior is identical to a call to Fn utimes .

RETURN VALUES

Rv -std

ERRORS

All of the system call will fail if:

Bq Er EACCES: Search permission is denied for a component of the path prefix.
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 path or Fa times argument points outside the process's allocated address space.
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 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 flags set. See the chflags(2) manual page for more information.
Bq Er EROFS: The file system containing the file is mounted read-only.

The Fn futimes system call will fail if:

Bq Er EBADF: The Fa fd argument does not refer to a valid descriptor.

In addition to the errors returned by the Fn utimes , the Fn futimesat may fail if:

Bq Er EBADF: The Fa path argument does not specify an absolute path and the Fa fd argument is neither AT_FDCWD nor a valid file descriptor open for searching.
Bq Er ENOTDIR: The Fa path argument is not an absolute path and Fa fd is neither AT_FDCWD nor a file descriptor associated with a directory.

STANDARDS

The Fn utimes function is expected to conform to St -xpg4.2 . The Fn futimesat system call follows The Open Group Extended API Set 2 specification.

HISTORY

The Fn utimes system call appeared in BSD 4.2 The Fn futimes and Fn lutimes system calls first appeared in Fx 3.0 . The Fn futimesat system call appeared in Fx 8.0 .