utime(3p) — Linux manual page

PROLOG | NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | EXAMPLES | APPLICATION USAGE | RATIONALE | FUTURE DIRECTIONS | SEE ALSO | COPYRIGHT

UTIME(3P)               POSIX Programmer's Manual              UTIME(3P)

PROLOG         top

       This manual page is part of the POSIX Programmer's Manual.  The
       Linux implementation of this interface may differ (consult the
       corresponding Linux manual page for details of Linux behavior),
       or the interface may not be implemented on Linux.

NAME         top

       utime — set file access and modification times

SYNOPSIS         top

       #include <utime.h>

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

DESCRIPTION         top

       The utime() function shall set the access and modification times
       of the file named by the path argument.

       If times is a null pointer, the access and modification times of
       the file shall be set to the current time. The effective user ID
       of the process shall match the owner of the file, or the process
       has write permission to the file or has appropriate privileges,
       to use utime() in this manner.

       If times is not a null pointer, times shall be interpreted as a
       pointer to a utimbuf structure and the access and modification
       times shall be set to the values contained in the designated
       structure. Only a process with the effective user ID equal to the
       user ID of the file or a process with appropriate privileges may
       use utime() this way.

       The utimbuf structure is defined in the <utime.h> header. The
       times in the structure utimbuf are measured in seconds since the
       Epoch.

       Upon successful completion, the utime() function shall mark the
       last file status change timestamp for update; see <sys/stat.h>.

RETURN VALUE         top

       Upon successful completion, 0 shall be returned. Otherwise, -1
       shall be returned and errno shall be set to indicate the error,
       and the file times shall not be affected.

ERRORS         top

       The utime() function shall fail if:

       EACCES Search permission is denied by a component of the path
              prefix; or the times argument is a null pointer and the
              effective user ID of the process does not match the owner
              of the file, the process does not have write permission
              for the file, and the process does not have appropriate
              privileges.

       ELOOP  A loop exists in symbolic links encountered during
              resolution of the path argument.

       ENAMETOOLONG
              The length of a component of a pathname is longer than
              {NAME_MAX}.

       ENOENT A component of path does not name an existing file or path
              is an empty string.

       ENOTDIR
              A component of the path prefix names an existing file that
              is neither a directory nor a symbolic link to a directory,
              or the path argument contains at least one non-<slash>
              character and ends with one or more trailing <slash>
              characters and the last pathname component names an
              existing file that is neither a directory nor a symbolic
              link to a directory.

       EPERM  The times argument is not a null pointer and the effective
              user ID of the calling process does not match the owner of
              the file and the calling process does not have appropriate
              privileges.

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

       The utime() function may fail if:

       ELOOP  More than {SYMLOOP_MAX} symbolic links were encountered
              during resolution of the path argument.

       ENAMETOOLONG
              The length of a pathname exceeds {PATH_MAX}, or pathname
              resolution of a symbolic link produced an intermediate
              result with a length that exceeds {PATH_MAX}.

       The following sections are informative.

EXAMPLES         top

       None.

APPLICATION USAGE         top

       Since the utimbuf structure only contains time_t variables and is
       not accurate to fractions of a second, applications should use
       the utimensat() function instead of the obsolescent utime()
       function.

RATIONALE         top

       The actime structure member must be present so that an
       application may set it, even though an implementation may ignore
       it and not change the last data access timestamp on the file. If
       an application intends to leave one of the times of a file
       unchanged while changing the other, it should use stat() or
       fstat() to retrieve the file's st_atim and st_mtim parameters,
       set actime and modtime in the buffer, and change one of them
       before making the utime() call.

FUTURE DIRECTIONS         top

       The utime() function may be removed in a future version.

SEE ALSO         top

       fstat(3p), fstatat(3p), futimens(3p)

       The Base Definitions volume of POSIX.1‐2017, sys_stat.h(0p),
       utime.h(0p)

COPYRIGHT         top

       Portions of this text are reprinted and reproduced in electronic
       form from IEEE Std 1003.1-2017, Standard for Information
       Technology -- Portable Operating System Interface (POSIX), The
       Open Group Base Specifications Issue 7, 2018 Edition, Copyright
       (C) 2018 by the Institute of Electrical and Electronics
       Engineers, Inc and The Open Group.  In the event of any
       discrepancy between this version and the original IEEE and The
       Open Group Standard, the original IEEE and The Open Group
       Standard is the referee document. The original Standard can be
       obtained online at http://www.opengroup.org/unix/online.html .

       Any typographical or formatting errors that appear in this page
       are most likely to have been introduced during the conversion of
       the source files to man page format. To report such errors, see
       https://www.kernel.org/doc/man-pages/reporting_bugs.html .

IEEE/The Open Group               2017                         UTIME(3P)

Pages that refer to this page: time.h(0p)utime.h(0p)pax(1p)touch(1p)asctime(3p)clock(3p)ctime(3p)difftime(3p)fstatvfs(3p)futimens(3p)gmtime(3p)localtime(3p)mktime(3p)strftime(3p)time(3p)