PROLOG

       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

       utime — set file access and modification times

SYNOPSIS

       #include <utime.h>

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

DESCRIPTION

       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

       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

       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

       None.

APPLICATION USAGE

       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

       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

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

SEE ALSO

       fstat(), fstatat(), futimens()

       The Base Definitions volume of POSIX.1‐2017, <sys_stat.h>, <utime.h>

COPYRIGHT

       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 .