INF: tmpfile() Creates a Temporary File in the Root Directory

ID Number: Q51326

5.10 6.00 6.00a 6.00ax 7.00

MS-DOS

Summary:

The Microsoft C run-time library function tmpfile() creates a

temporary file in the root directory of the current drive. This file

has read/write access and is automatically deleted when the file is

closed.

The documentation for this function implies that the file will be

created in the current working directory. This is not the case; the

file will exist only in the root directory. To create a temporary file

in a different directory, use the functions tmpname() or tempname() in

conjunction with fopen().

Some obscure side effects can occur on some systems as a result of

tmpfile() creating a file in the root directory. On a network, you

must have read/write privileges for the root directory of your current

drive. Without these rights, tmpfile() will fail to open the temporary

file, returning a NULL in the process.

Another possible reason tmpfile() might fail is if the root directory

is full. MS-DOS allows only a limited amount of file entries in the

root directory depending on the disk format; therefore, if the root is

full, you must delete some files before you use tmpfile().

Additional reference words: 5.10 6.00 6.00a 6.00ax 7.00 Novell