NAME

     utimes, lutimes, futimes, futimesat — set file access and modification times

LIBRARY

     Standard C Library (libc, -lc)

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);

     int
     futimesat(int fd, const char *path, 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.

     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.

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

RETURN VALUES

     Upon successful completion, the value 0 is returned; otherwise the value -1 is returned and
     the global variable errno is set to indicate the error.

ERRORS

     The utimes() and lutimes() system calls 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]           The path or times argument 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.

     [EPERM]            The named file has its immutable or append-only flag set, see the
                        chflags(2) manual page for more information.

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

     The futimes() system call will fail if:

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

     All of the system calls will fail if:

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

     [EINVAL]           The tv_usec component of at least one of the values specified by the
                        times argument has a value less than 0 or greater than 999999.

     [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.

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

     [EBADF]            The path argument does not specify an absolute path and the fd argument
                        is neither AT_FDCWD nor a valid file descriptor open for searching.

     [ENOTDIR]          The path argument is not an absolute path and fd is neither AT_FDCWD nor
                        a file descriptor associated with a directory.

SEE ALSO

     chflags(2), stat(2), utime(3)

STANDARDS

     The utimes() function is expected to conform to X/Open Portability Guide Issue 4, Version 2
     (“XPG4.2”).  The futimesat() system call follows The Open Group Extended API Set 2
     specification.

HISTORY

     The utimes() system call appeared in 4.2BSD.  The futimes() and lutimes() system calls first
     appeared in FreeBSD 3.0.  The futimesat() system call appeared in FreeBSD 8.0.