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,  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, Copyright (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.opengroup.org/unix/online.html .