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



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

NNAAMMEE
       utime -- set file access and modification times

SSYYNNOOPPSSIISS
       #include <utime.h>

       int utime(const char *_p_a_t_h, const struct utimbuf *_t_i_m_e_s);

DDEESSCCRRIIPPTTIIOONN
       The _u_t_i_m_e() function shall set the access and modification times of the
       file named by the _p_a_t_h argument.

       If _t_i_m_e_s 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 _u_t_i_m_e() in
       this manner.

       If _t_i_m_e_s is not a null pointer, _t_i_m_e_s shall be interpreted as a pointer
       to a uuttiimmbbuuff 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 _u_t_i_m_e() this way.

       The uuttiimmbbuuff structure is defined in the _<_u_t_i_m_e_._h_> header. The times in
       the structure uuttiimmbbuuff are measured in seconds since the Epoch.

       Upon successful completion, the _u_t_i_m_e() function shall mark the last
       file status change timestamp for update; see _<_s_y_s_/_s_t_a_t_._h_>.

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

EERRRROORRSS
       The _u_t_i_m_e() function shall fail if:

       EEAACCCCEESS Search permission is denied by a component of the path prefix;
              or the _t_i_m_e_s 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.

       EELLOOOOPP  A loop exists in symbolic links encountered during resolution of
              the _p_a_t_h argument.

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

       EENNOOEENNTT A component of _p_a_t_h does not name an existing file or _p_a_t_h is an
              empty string.

       EENNOOTTDDIIRR
              A component of the path prefix names an existing file that is
              neither a directory nor a symbolic link to a directory, or the
              _p_a_t_h 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.

       EEPPEERRMM  The _t_i_m_e_s 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.

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

       The _u_t_i_m_e() function may fail if:

       EELLOOOOPP  More than {SYMLOOP_MAX} symbolic links were encountered during
              resolution of the _p_a_t_h argument.

       EENNAAMMEETTOOOOLLOONNGG
              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}.

       _T_h_e _f_o_l_l_o_w_i_n_g _s_e_c_t_i_o_n_s _a_r_e _i_n_f_o_r_m_a_t_i_v_e_.

EEXXAAMMPPLLEESS
       None.

AAPPPPLLIICCAATTIIOONN UUSSAAGGEE
       Since the uuttiimmbbuuff structure only contains ttiimmee__tt variables and is not
       accurate to fractions of a second, applications should use the
       _u_t_i_m_e_n_s_a_t() function instead of the obsolescent _u_t_i_m_e() function.

RRAATTIIOONNAALLEE
       The _a_c_t_i_m_e 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 _s_t_a_t() or _f_s_t_a_t() to retrieve the file's _s_t___a_t_i_m and _s_t___m_t_i_m
       parameters, set _a_c_t_i_m_e and _m_o_d_t_i_m_e in the buffer, and change one of
       them before making the _u_t_i_m_e() call.

FFUUTTUURREE DDIIRREECCTTIIOONNSS
       The _u_t_i_m_e() function may be removed in a future version.

SSEEEE AALLSSOO
       _f_s_t_a_t(), _f_s_t_a_t_a_t(), _f_u_t_i_m_e_n_s()

       The Base Definitions volume of POSIX.1-2017, <<ssyyss__ssttaatt..hh>>, <<uuttiimmee..hh>>

CCOOPPYYRRIIGGHHTT
       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(3)
