FIX: F6415 or F6417 From Attempt to Open More than 123 Files

The information in this article applies to:

• Microsoft FORTRAN for MS-DOS and OS/2, version 5.0

SYMPTOMS

After following the procedure to increase the maximum number of simultaneous open files to 128 or larger, an attempt to open more than 123 files fails and one of the following run-time errors occurs:

   F6415: OPEN(file name)
   - file already exists

   -or-

   F6417: OPEN(file name)
   - too many open files

STATUS

Microsoft has confirmed this to be a problem in FORTRAN version 5.0 for MS-DOS and OS/2. This problem was corrected in FORTRAN version 5.1 for MS-DOS and OS/21.

MORE INFORMATION

If 123 files are already open and the 124th file does not exist, the run-time library generates the F6415 error; if the 124th file exists, the run-time library generates the F6417 error. On some systems, the errors occur after opening 122 files. On other systems, if the 124th file does not exist, the run-time library creates the file before generating the error message.

The procedure to increase the maximum number of simultaneously open files is documented on pages 405 and 406 of the Microsoft FORTRAN "Reference" manual for versions 5.0 and 5.1.

Because FORTRAN reserves five file handles for its own use, this error occurs when the application requests the 129th file handle. However, the absolute maximum number of simultaneously open files is documented on page 405 of the "Reference" manual as 256.