ANSI draft - seeking to eof

[jimc at ucla-cs.UUCP]

In article <189 at brl-tgr.ARPA> gwyn at brl-tgr.ARPA (Doug Gwyn <gwyn>) writes:
>> The latest (November 11) draft from X3J11 says this about fseek():
>> 	int fseek (FILE *stream, long offset, int ptrname)
>> 	A binary stream need not meaningfully support fseek
>> 	calls with a ptrname value of SEEK_END.
>> 				[X3J11/85-138, page 109]
>
>It says you can seek to the end of a text stream but not a binary
>stream.  This is interesting; one wonders what systems they had
>in mind that can do the one but not the other.
>
For one, CP/M records the ending block of a file but not the byte within
block.  If you want to know where the end is you (the library routine) have
to insert some code, like ^Z for text, and look for it on reading, or search
the last block for it on fseek(,,SEEK_END).  Obviously this doesn't work in
binary files. Often the application program has records of the form: byte
count, record type, binary data; and one of the types means EOF.

James F. Carter            (213) 206-1306
UCLA-SEASnet; 2567 Boelter Hall; 405 Hilgard Ave.; Los Angeles, CA 90024
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