[m-rev.] io__read_file_as_string (was: improve `_init.c' file creation)

[Fergus Henderson]

On 28-Nov-2001, Simon Taylor <stayl at cs.mu.OZ.AU> wrote:
> On 28-Nov-2001, Fergus Henderson <fjh at cs.mu.OZ.AU> wrote:
> > On 28-Nov-2001, Simon Taylor <stayl at cs.mu.OZ.AU> wrote:
> > > > > +		% XXX Why does `io__read_file_as_string' return a separate
> > > > > +		% status and result, rather than an `io__res(string)'?
> > > > 
> > > > The reason is to ensure that, in the case when some characters are
> > > > successfully read and then an I/O error occurs, the part of the file
> > > > that was successfully read can be returned.
> > > 
> > > When is that behaviour useful?
> > 
> > When the error is something such as EINTR.
> > 
> > When implementing programs such as `cat', which should output all that
> > it successfully reads before reporting a read error.
>  
> `io__read_file' is inappropriate for this kind of application
> because the size of the input is not bounded.

Well, perhaps not for the generic `cat' program,
but I can imagine a lot of cat-like utilities
(rot13, toupper, etc.) for which read_file_as_string
might well be appropriate, but for which the same principle
applies.

> > When the error occurs because the input file is `stdin',
> > and the user's dialup connection has just been disconnected
> > due to a Telstra fault.  The data may be hard for the user
> > to reproduce, so the program should not just throw it away.
> 
> Applications taking user input from stdin generally don't use
> `io__read_file' to read it.

Nevertheless, the interface should allow this use of io__read_file_as_string.

-- 
Fergus Henderson <fjh at cs.mu.oz.au>  |  "I have always known that the pursuit
The University of Melbourne         |  of excellence is a lethal habit"
WWW: <http://www.cs.mu.oz.au/~fjh>  |     -- the last words of T. S. Garp.
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