Q65642: getcwd() and _getdcwd Return Backslash for Root Requests

Article: Q65642
Product(s): See article
Version(s): 5.x 6.00 | 5.x 6.00
Operating System(s): MS-DOS | OS/2
Keyword(s): ENDUSER | buglist6.00 s_quickc | mspl13_c
Last Modified: 24-OCT-1990

The Microsoft C version 6.00 library functions getcwd() and _getdcwd()
will append a backslash to the drive specification for requests made
from a drive's root directory.

General requests made to the getcwd() or _getdcwd() function will not
place a final backslash after the directory name. For example, when
called from c:\dos\foo\ the return value of getcwd() will be
c:\dos\foo. However, when invoked from a drive's root directory, the
backslash character is appended (for example, when called from d:\ the
return value is d:\). This inconsistent behavior can cause problems
when programs append a backslash followed by a filename to the return
of getcwd() in order to create data files in the current working
directories. In these cases it is important to check for the root
directory condition, in which case a backslash need not be appended.

The following code demonstrates the possible conflict; it will fail
when the default directory is a drive's root directory:

Sample Code
-----------

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

void main(void)
{
   FILE *fp;
   char buffer[_MAX_DIR+13];
   if (getcwd(buffer,_MAX_DIR)==NULL)
      perror("getcwd error");
   else
   {
      strcat(buffer,"\\test.dat");
      if((fp=fopen(buffer,"w"))!=NULL)
         fputs("hello",fp);
      else
         puts("failure in writing to current drive\n");
   }
}
Microsoft has confirmed this to be a problem in C version 6.00. We are
researching this problem and will post new information here as it
becomes available.

THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY.

Copyright Microsoft Corporation 1986-2002.