UTIME

NAME

SYNOPSIS

#include <sys/types.h>


#include <utime.h>

int utime(const char *filename, const struct utimbuf *times);

#include <sys/time.h>

int utimes(const char *filename, const struct timeval times[2]);

DESCRIPTION

If times is NULL, then the access and modification times of the file are set to the current time.

Changing timestamps is permitted when: either the process has appropriate privileges, or the effective user ID equals the user ID of the file, or times is NULL and the process has write permission for the file.

The utimbuf structure is:

struct utimbuf {
    time_t actime;       /* access time */
    time_t modtime;      /* modification time */
};

The utime() system call allows specification of timestamps with a resolution of 1 second.

The utimes() system call is similar, but the times argument refers to an array rather than a structure. The elements of this array are timeval structures, which allow a precision of 1 microsecond for specifying timestamps. The timeval structure is:

struct timeval {
    long tv_sec;        /* seconds */
    long tv_usec;       /* microseconds */
};

times[0] specifies the new access time, and times[1] specifies the new modification time. If times is NULL, then analogously to utime(), the access and modification times of the file are set to the current time.  

RETURN VALUE

ERRORS

EACCES

Search permission is denied for one of the directories in the path prefix of path (see also path_resolution(7)).

EACCES

times is NULL, the caller's effective user ID does not match the owner of the file, the caller does not have write access to the file, and the caller is not privileged (Linux: does not have either the CAP_DAC_OVERRIDE or the CAP_FOWNER capability).

ENOENT

filename does not exist.

EPERM

times is not NULL, the caller's effective UID does not match the owner of the file, and the caller is not privileged (Linux: does not have the CAP_FOWNER capability).

EROFS

path resides on a read-only file system.

CONFORMING TO

NOTES

In libc4 and libc5, utimes() is just a wrapper for utime() and hence does not allow a subsecond resolution.  

SEE ALSO

COLOPHON