huschi.net

UTIME(3P)                  POSIX Programmer's Manual                 UTIME(3P)
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 resolu-
              tion  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 utimen-
       sat() 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.1-2008, <sys_stat.h>, <utime.h>
COPYRIGHT
       Portions of this text are reprinted and reproduced in  electronic  form
       from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology
       -- Portable Operating System Interface (POSIX),  The  Open  Group  Base
       Specifications Issue 7, Copyright (C) 2013 by the Institute of Electri-
       cal and Electronics Engineers,  Inc  and  The  Open  Group.   (This  is
       POSIX.1-2008  with  the  2013  Technical Corrigendum 1 applied.) 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.unix.org/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.ker-
       nel.org/doc/man-pages/reporting_bugs.html .
IEEE/The Open Group                  2013                            UTIME(3P)