🚀 go-pugleaf

In article <BsJnKx.5yF@jrd.dec.com> diamond@jit.dec.com (Norman Diamond) writes:
>In article <1992Aug05.081224.17647@x.co.uk> clive@x.co.uk (Clive Feather) writes:
>>>> [In some other article, whose attribution is gone, someone wrote:]
>>>>>> In the section on fopen (4.9.5.3, pp. 130--131), the Standard says:
>>>>>>     Opening a file with append mode (|'a'| as the first character in
>>>>>>     the |mode| argument) causes all subsequent writes to the file to be
>>>>>>     forced to the then current end-of-file, regardless of intervening
>>>>>>     calls to the |fseek| function. ...
>> The original quotation is slightly wrong: it (section 7.9.5.3 "fopen")
>> actually says:
>>| Opening a file with append mode ('a' as the first character in the
>>| mode argument) causes all subsequent writes to the file to be forced to
>>| the then current end-of-file, regardless of intervening calls to the
>>| lseek function.

> The original version matches the ANSI Dec. 1988 draft, and furthermore ANSI
> doesn't have lseek, so I'm suspicious of this "correction."

The original version also matches the ISO standard. I must have had a
brainstorm. Sorry.

> Are subsequent writes also forced to the current end-of-file regardless of
> intervening calls to the fsetpos function and the rewind function?  Or do
> they not get forced in those situations, in which Chris Torek's reported
> observations were of correct implementations?  Or does the result become
> undefined (due to not being specified as unspecified or any other less
> serious alternative to undefined)?

They are written to the end of the stream - I covered this in the cited
posting. *I* interpret the standard as requiring each buffer-full (see
setvbuf) to be written to the current EOF - provided that the underlying
system can do it at all - but you may have a different opinion.

-- 
Clive D.W. Feather     | IXI Limited         | If you lie to the compiler,
clive@x.co.uk          | 62-74 Burleigh St.  | it will get its revenge.
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