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 (con-
       sult 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  appro-
       priate 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 modifi-
       cation 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, utime() shall mark the time of the last file status change,  st_ctime,  to  be  updated;  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 the path argument exceeds {PATH_MAX} or a pathname component 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 is not a directory.

       EPERM  The times argument is not a null pointer and the calling process' effective user ID does not match  the  owner  of
              the file and the calling process does not have the 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
              As  a  result  of  encountering  a symbolic link in resolution of the path argument, the length of the substituted
              pathname string exceeded {PATH_MAX}.


       The following sections are informative.

EXAMPLES
       None.

APPLICATION USAGE
       None.

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 access time 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() to retrieve the file's st_atime and st_mtime parameters,  set  actime  and
       modtime in the buffer, and change one of them before making the utime() call.

FUTURE DIRECTIONS
       None.

SEE ALSO
       The Base Definitions volume of IEEE Std 1003.1-2001, <sys/stat.h>, <utime.h>

COPYRIGHT
       Portions  of  this  text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition, Standard for
       Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6,  Copy-
       right (C) 2001-2003 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.open-
       group.org/unix/online.html .



IEEE/The Open Group                                           2003                                                     UTIME(3P)