June 17, 2008 UTIMES 2

### NAME

utimes, lutimes, futimes - set file access and modification times

### LIBRARY

Standard C Library (libc, -lc)

### SYNOPSIS

```int` utimes(```const char *path``, const struct timeval times[2]`)
```int` lutimes(```const char *path``, const struct timeval times[2]`)
```int` futimes(```int fd``, 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.

lutimes(``) 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

Upon successful completion, a value of 0 is returned. Otherwise, a value of -1 is returned and errno is set to indicate the error.

### ERRORS

utimes(``) and lutimes(``) will fail if:

[```EACCES`]
  Search permission is denied for a component of the path prefix; or 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`]
  ```path` or ```times` points outside the process's allocated address space.

[```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 exceeded ```{PATH_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.

[```EROFS`]
  The file system containing the file is mounted read-only.

futimes(``) will fail if:

[```EBADF`]
  ```fd` does not refer to a valid descriptor.

[```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`]
  ```times` points outside the process's allocated address space.

[```EIO`]
  An I/O error occurred while reading or writing the affected inode.

[```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.

[```EROFS`]
  The file system containing the file is mounted read-only.

### SEE ALSO

stat(2), utime(3), symlink(7)

### HISTORY

The utimes(``) function call appeared in 4.2BSD. The futimes(``) function call appeared in NetBSD1.2. The lutimes(``) function call appeared in NetBSD1.3. Birthtime setting support was added in NetBSD5.0.