Q43073: The Function fopen Accepts Filenames with Embedded Spaces

Article: Q43073
Product(s): See article
Version(s): 5.10   | 5.10
Operating System(s): MS-DOS | OS/2
Keyword(s): ENDUSER | s_quickc | mspl13_c
Last Modified: 17-MAY-1989

The Microsoft run-time library functions fopen and open do not screen
for invalid filenames. These functions will accept a filename string
with an embedded space. For example, the following program will create
the file "he llo.dat" (without the quotation marks):

#include <stdio.h>
FILE *fh;
void main(void)  {
   fh = fopen ("he llo.dat", "w+);
}

This error is not the result of a problem with fopen or open. The
functions fopen and open should not be expected to screen filenames.
This activity should be handled by the program using these routines.
Filename screening is not specified in the "Microsoft C for the MS-DOS
Operating System: Run-Time Library Reference" manual; this applies to
both MS-DOS and OS/2.

However, the creation of this file could cause some difficulties under
DOS. The simplest way to delete such a file would be "del *.dat"
(without the quotation marks).

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