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Re: fread a file of unknown size

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fmassei@gmail.com wrote:

> On Sunday, March 8, 2015 at 7:59:16 PM UTC+1, Richard Heathfield wrote:
> > fread ought to return the number of bytes read. Instead, it returns the 
> > number of blocks. I expect there was a good reason once.
> 
> Maybe there's one even today: if you are interested in bytes you just put
> 1 in the second parameter, but if you are reading, let's say, fixed-length
> structures, maybe the number of items read would be more useful.
> 
> .. dunno.
> 
> I also believe that returning the number of bytes would have made much more
> sense.

Let's put it this way.

If you're interested in the number of bytes read, getting that from
fread() is easy: use a 1 for the block size.

If you're interested in the number of intact records read, getting that
from fread() is just as easy: use the size of the record for the block
size.

If you want a hypothetical freadbytes() where you don't have to specify
that you want to know the number of bytes, that's easy to implement in
terms of fread(). Going the other way isn't hard, but it requires an
extra calculation that fread() now doesn't.

There was no good reason to restrict fread() to report bytes only, and
some good reason to allow it to report record size.

Richard

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Thread

fread a file of unknown size ruben safir <ruben@mrbrklyn.com> - 2015-03-08 14:47 -0400
  Re: fread a file of unknown size Richard Heathfield <rjh@cpax.org.uk> - 2015-03-08 18:59 +0000
    Re: fread a file of unknown size James Kuyper <jameskuyper@verizon.net> - 2015-03-08 18:21 -0400
      Re: fread a file of unknown size Keith Thompson <kst-u@mib.org> - 2015-03-08 18:43 -0700
    Re: fread a file of unknown size fmassei@gmail.com - 2015-03-08 15:41 -0700
      Re: fread a file of unknown size raltbos@xs4all.nl (Richard Bos) - 2015-03-10 16:04 +0000
    Re: fread a file of unknown size Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2015-03-08 18:44 -0400
  Re: fread a file of unknown size jacob navia <jacob@spamsink.net> - 2015-03-08 20:32 +0100
  Re: fread a file of unknown size Keith Thompson <kst-u@mib.org> - 2015-03-08 12:48 -0700
  Re: fread a file of unknown size glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-03-08 23:39 +0000
    Re: fread a file of unknown size James Kuyper <jameskuyper@verizon.net> - 2015-03-08 20:40 -0400
      Re: fread a file of unknown size glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-03-09 01:24 +0000
        Re: fread a file of unknown size Keith Thompson <kst-u@mib.org> - 2015-03-09 07:53 -0700
          Re: fread a file of unknown size glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-03-09 17:36 +0000
            Re: fread a file of unknown size Keith Thompson <kst-u@mib.org> - 2015-03-09 10:44 -0700
              Re: fread a file of unknown size glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-03-09 20:07 +0000

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