/* ... */
f = fopen("some-file" , "r") ;
if ( f == NULL ) {
/* Exits */
}
clearerr(f) ;
while ( ( a=getc(f) ) != EOF ) {
/* Do stuff */
}
if ( ferror(f) ) {
/* Exits */
}

Is the call to clearerr() necessary ? If ferror() returns 0
can one be reasonably certain that the whole file has been
read ?

In article
<e949195b-e2e6-4922-9ebf-afa412746d5f@b32g2000hsa.googlegroups.com>,
Spiros Bousbouras <spibou@gmail.com> wrote on Monday 19 Nov 2007 8:52
pm:

> /* ... */
> f = fopen("some-file" , "r") ;
> if ( f == NULL ) {
> /* Exits */
> }
> clearerr(f) ;
> while ( ( a=getc(f) ) != EOF ) {
> /* Do stuff */
> }
> if ( ferror(f) ) {
> /* Exits */
> }
>
> Is the call to clearerr() necessary ?

I don't believe so.

> If ferror() returns 0 can one be reasonably certain that the whole
> file has been read ?

Within the constraints of Standard C, I think that might be a reasonable
conclusion.

I generally test explicitly with feof() as well, even if ferror()
returns false. Just a habit.