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From: otto@tukki.jyu.fi (Otto J. Makela)
Newsgroups: comp.lang.c
Subject: Re: Turbo C, fopen(), fprintf() and ^Z - I need help!!
Message-ID: <OTTO.90Sep20180445@tukki.jyu.fi>
Date: 20 Sep 90 16:04:45 GMT
References: <38742@ucbvax.BERKELEY.EDU> <14084@mentor.cc.purdue.edu> <1990Sep20.014132.29461@druid.uucp>
Sender: news@tukki.jyu.fi (News articles)
Organization: Turing Police, Criminal AI section
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In-Reply-To: darcy@druid.uucp's message of 20 Sep 90 01:41:32 GMT

In article <1990Sep20.014132.29461@druid.uucp> darcy@druid.uucp (D'Arcy J.M. Cain) writes:
[how to position file to skip trailing ^Z's on brain-dead CP/M -like systems]
       long pos = 0;
       ...
       do { fseek(fp, --pos, SEEK_END) } while ((c = fgetc(fp)) == 0x1a);
       fseek(fp, ++pos, SEEK_END);

Be careful with this stuff.  Because you reseek as the last thing you do,
this will work.  I have seen several C librarys which get confused when
you seek, read and then write a stream (probably some buffering messing
things up).  Or is this perhaps (horror of horrors) standard behaviour ?
I wrote code like:
	fseek(fp, -1L, SEEK_END);
	while(fgetc(fp)==0x1A) fseek(fp, -2L, SEEK_CUR);
At this point I assumed the file would be positioned correctly.  Didn't
work on DOS, didn't work on BSD Unix.  I had to add:
	fseek(fp, 0L, SEEK_CUR);

But you of course were aware of this.
--
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