PRB: _dos_setftime() Fails to Set Date & Time for Network File

MS-DOS                      | OS/2            | WINDOWS

The information in this article applies to:

• The C Run-time (CRT), included with:

      - Microsoft C for MS-DOS, versions 5.1, 6.0, 6.0a, and 6.0ax
      - Microsoft C for OS/2, versions 5.1, 6.0, and 6.0a
      - Microsoft C/C++ for MS-DOS, version 7.0
      - Microsoft Visual C++ for Windows, versions 1.0 and 1.5
  

SYMPTOMS

The _dos_setftime() function is used to set the date and time of a file. If the file is on a local drive, the function behaves as expected; however, if the file resides on a network drive, the date and time returned by subsequent _dos_getftime() will not return the new values.

The date and time of the file on the network will be set. However, _dos_getftime() will not recognize the change until the file has been closed and re-opened.

STATUS

The C run-time library is performing as expected. The problem is a limitation of either the operating system or the network software.

MORE INFORMATION

Sample Code

/* Compile options needed: none
*/

#include <stdio.h>
#include <dos.h>
#include <stdlib.h>
#include <fcntl.h>

void main(void)

    int fh;
    unsigned int new_date = 0x184f;     /*   2/15/92   */
    unsigned int new_time = 0x48e0;     /*   9:07 AM   */
    unsigned int old_time, old_date;

   if( _dos_open("test.dat", O_RDONLY, &fh) != 0)
      exit(1);

   _dos_getftime( fh, &old_date, &old_time );
   system("dir test.dat");

   _dos_setftime( fh, new_date, new_time );
   system("dir test.dat");

   _dos_close( fh );
   if( _dos_open("test.dat", O_RDONLY, &fh) != 0)
      exit(1);

   printf("\nAfter closing and reopening the file.\n");
   _dos_getftime( fh, &old_date, &old_time );
   system("dir test.dat");