The rename function may fail when you use the rename function to change a directory name that is the current working directory (60028)

MORE INFORMATION

In MS-DOS versions 3.x when SHARE.EXE is not installed, the sample program shown below produces the following results:

   C:\>cd olddir
   C:\OLDDIR>d:
   D:>test
   Rename is successful  <--- Output from test program
   D:>c:
   C:\OLDDIR>      <--- The old directory is not renamed
				

In MS-DOS version 3.3 when SHARE.EXE is installed, in MS-DOS versions 4.x and later, in an MS-DOS window in OS/2, or in an MS-DOS window in Windows NT, the sample program produces the following results:

   C:\>cd olddir
   C:\OLDDIR>d:
   D:>test
   Rename fails with errno = 13  <--- Output from test program
   D:>c:
   C:\OLDDIR>            <--- The old directory is not renamed
				

Note errno code 13 indicates an access violation.

This behavior does not indicate a problem with the rename() function. It simply maps to an Interrupt 21h, Function 56h (Rename File) call in MS-DOS. The problem occurs because the operating system maintains a list of the current working directory (CWD) for each drive in its drive table in memory.

In the MS-DOS 3.x example, the program successfully changed the directory name. However, because MS-DOS does not recognize the change, it does not update the CWD in the drive table. When the program ends, MS-DOS displays an invalid prompt that reflects the old directory name. If you type "CD \NEWDIR" at the MS-DOS prompt, the drive table is updated.

In the second example, MS-DOS 3.3 with SHARE.EXE installed, MS-DOS versions 4.x and later, and MS-DOS running in OS/2 cannot determine if another process is using the directory and an access violation error occurs.

On Windows NT and Windows 2000, if any process is active in the target directory, the system does not change the directory name. When this happens, the function returns an error code 13 that indicates an access violation. On Windows Millennium Edition (Me), the function succeeds.

Sample code

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

char szOldName[] = "c:\\olddir";
char szNewName[] = "c:\\newdir";

extern int errno;

void main (void)
{
   if (0 != rename(szOldName, szNewName))
      printf("Rename fails with errno = %d\n", errno);
   else
      printf("Rename is successful\n");
}