Seeing next character in an file

[Bengt Richter]

On Mon, 28 Jul 2003 12:54:57 +0100, Richie Hindle <richie at entrian.com> wrote:

>
>[Keith]
>> def peek(self, cnt):
>>     data = self.read(cnt)
>>     self.seek(cnt * -1, 1)
>>     return data
>> 	
>> def peekline(self):
>>     pos = self.tell()
>>     data = self.readline()
>>     self.seek(pos, 0)
>>     return data
>
>[Bengt]
>> if you're going to seek/tell, best to do it in binary, and deal with the platform dependent EOLs.
>
>seek() works perfectly with text-mode files as long as you only seek to
>places given to you by tell().  So if Keith's peek() function had used
>tell() and then seek()ed (sought()? 8-) back to that point like his
>peekline() does, there would be no problem.
>
Can you cite a C or C++ standard section that guarantees that seek/tell
will work that way in text mode? (I'm not saying there isn't one, but
I couldn't find one quickly ;-)

Regards,
Bengt Richter