_futime, _futime32, _futime64

Sets the modification time on an open file.

Syntax

int _futime(
   int fd,
   struct _utimbuf *filetime
);
int _futime32(
   int fd,
   struct __utimbuf32 *filetime
);
int _futime64(
   int fd,
   struct __utimbuf64 *filetime
);

Parameters

fd
File descriptor to the open file.

filetime
Pointer to the structure containing the new modification date.

Return Value

Return 0 if successful. If an error occurs, the invalid parameter handler is invoked, as described in Parameter Validation. If execution is allowed to continue, the function returns -1 and errno is set to EBADF, indicating an invalid file descriptor, or EINVAL, indicating an invalid parameter.

Remarks

The _futime routine sets the modification date and the access time on the open file associated with fd. _futime is identical to _utime, except that its argument is the file descriptor of an open file, rather than the name of a file or a path to a file. The _utimbuf structure contains fields for the new modification date and access time. Both fields must contain valid values. _utimbuf32 and _utimbuf64 are identical to _utimbuf except for the use of the 32-bit and 64-bit time types, respectively. _futime and _utimbuf use a 64-bit time type and _futime is identical in behavior to _futime64. If you need to force the old behavior, define _USE_32BIT_TIME_T. Doing this causes _futime to be identical in behavior to _futime32 and causes the _utimbuf structure to use the 32-bit time type, making it equivalent to __utimbuf32.

_futime64, which uses the __utimbuf64 structure, can read and modify file dates through 23:59:59, December 31, 3000, UTC; whereas a call to _futime32 fails if the date on the file is later than 23:59:59 January 18, 2038, UTC. Midnight, January 1, 1970, is the lower bound of the date range for these functions.

Requirements

Function Required header Optional header
_futime <sys/utime.h> <errno.h>
_futime32 <sys/utime.h> <errno.h>
_futime64 <sys/utime.h> <errno.h>

For more compatibility information, see Compatibility.

Example

// crt_futime.c
// This program uses _futime to set the
// file-modification time to the current time.

#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <io.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/utime.h>
#include <share.h>

int main( void )
{
   int hFile;

   // Show file time before and after.
   system( "dir crt_futime.c_input" );

   _sopen_s( &hFile, "crt_futime.c_input", _O_RDWR, _SH_DENYNO, 0 );

   if( _futime( hFile, NULL ) == -1 )
      perror( "_futime failed\n" );
   else
      printf( "File time modified\n" );

   _close (hFile);

   system( "dir crt_futime.c_input" );
}

Input: crt_futime.c_input

Arbitrary file contents.

Sample Output

Volume in drive Z has no label.
Volume Serial Number is 5C68-57C1

Directory of Z:\crt

03/25/2004  10:40 AM                24 crt_futime.c_input
               1 File(s)             24 bytes
               0 Dir(s)  24,268,476,416 bytes free
Volume in drive Z has no label.
Volume Serial Number is 5C68-57C1

Directory of Z:\crt

03/25/2004  10:41 AM                24 crt_futime.c_input
               1 File(s)             24 bytes
               0 Dir(s)  24,268,476,416 bytes free
File time modified

See also

Time Management