J3/00-267

Date:    2000/08/18
To:      J3
From:    Matthijs van Waveren
Subject: C-Fortran I/O
Ref:     Issue 244 on page 172 of J3/00-007r2

Edits and references are to J3/00-007r2.

1. Analysis

Subgroup is of the opinion that Fortran 2000 should not allow the
Fortran and C parts of the code to perform I/O on the same files.

As mentioned in the note, the user might expect that the three files
connected to the units INPUT_UNIT, OUTPUT_UNIT, and ERROR_UNIT (page
340), could correspond to the three text streams, which are predefined
in C: standard input, standard output, and standard error.

Subgroup is of the opinion that the user should not assume that these
text streams correspond to each other. This is left as a
processor-dependent feature. The implementator might consider
combining these two text streams in his/her implementation.

2. Edits:

[171:36+] Add at the end of the paragraph:

"A unit shall not be connected to a file which is also connected to a
C stream."

[172:1-12] Delete J3 note

[172:12+] Add note

"C streams are described in section 7.19.2 of the C standard. Whether
the files connected to the units INPUT_UNIT, OUTPUT_UNIT, and
ERROR_UNIT correspond to the three text streams, which are predefined
in C: standard input, standard output, and standard error, is
processor-dependent."