DOC: mktemp() Creates a Maximum of 27 Unique Filenames

ID: Q50351

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, 6.0ax
- Microsoft C/C++ for MS-DOS, version 7.0
- Microsoft Visual C++ for Windows, versions 1.0, 1.5
- Microsoft Visual C++ 32-bit Edition, versions 1.0, 2.0

SUMMARY

In the Microsoft C online and printed documentation for the mktemp() function, it is not clear exactly how many filenames mktemp() can create. These references state the following:

When creating new names, mktemp uses, in order, "0" and the lowercase letters "a" to "z".

This information is correct. However, the documentation fails to mention that these are the only filenames that are created. Any further calls to mktemp() after these characters have been used will fail (that is, once "z" has been placed in the template). Therefore, the limit on the number of unique filenames that can be created by mktemp() is 27.

NOTE: This problem was fixed in the Books On-line of Microsoft Visual C++, 32-bit Edition, version 4.0.

Additional query words: 1.00 1.50 2.00 4.00 5.10 6.00 6.00a 6.00ax 7.00

Keywords : kbdocfix kbCRT kbVC
Version : winnt:
Platform : winnt
Issue type :