The utime() function sets the access and modification times of the file pointed to by path, and causes the time of the last file status change (st_ctime) to be updated.

If times is NULL, the access and modification times of the file are set to the current time. A process must be the owner of the file or have write permission to use utime() in this manner.

If times is not NULL, times is interpreted as a pointer to a utimbuf structure (defined in <utime.h>) and the access and modification times are set to the values contained in the designated structure. Only the owner of the file or the super-user may use utime() in this manner.

The utimbuf structure contains the following members:

time_t   actime;    /* access time */
time_t   modtime;   /* modification time */

The times contained in the members of the utimbuf structure are measured in seconds since 00:00:00 UTC, January 1, 1970.

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

The utime() function will fail if:

EACCES

Search permission is denied by a component of the path prefix; or the effective user ID of the process is not superuser and not the owner of the file, write permission is denied for the file, and times is NULL.

EFAULT

The path argument points to an illegal address.

EINTR

A signal was caught during the execution of the utime() function.

EIO

An I/O error occurred while reading from or writing to the file system.

ELOOP

Too many symbolic links were encountered in translating path.

ENAMETOOLONG

The length of the path argument exceeds PATH_MAX, or the length of a path component exceeds NAME_MAX while _POSIX_NO_TRUNC is in effect.

ENOENT

The named file does not exist or is a null pathname.

ENOLINK

The path argument points to a remote machine and the link to that machine is no longer active.

ENOTDIR

A component of the path prefix is not a directory.

EPERM

The effective user of the calling process is not super-user and not the owner of the file, and times is not NULL.

EROFS

The file system containing the file is mounted read-only.

See attributes(5) for descriptions of the following attributes:

stat(2), attributes(5)