On Wed, 23 Feb 2005, Hrvoje Niksic wrote:
> I see. Now I know why I didn't use AC_FUNC_FSEEKO -- Wget doesn't use
> fseeko anywhere. The only usage we have is:
>
> fseek (fp, 0, SEEK_END);
> size = ftell (fp); /* replaced with ftello where available */
>
> Is there need to use fseeko here?
Probably -- the Single Unix Specification, Version 2, which introduced
the "o" functions, quotes this error code:
[EOVERFLOW]
For fseek(), the resulting file offset would be a value which
cannot be represented correctly in an object of type long.
I don't know if it happens in practice (GNU libc seems to be forgiving, as
usual). But we do want to use ftello(), so we need AC_FUNC_FSEEKO anyway
as the _LARGEFILE_SOURCE restriction applies to both. This is what
autoconf manual says (yes, a reference to ftello() should really be
included in the AC_FUNC_FSEEKO description):
The LFS introduced the `fseeko' and `ftello' functions to replace
their C counterparts `fseek' and `ftell' that do not use `off_t'.
Take care to use `AC_FUNC_FSEEKO' to make their prototypes
available when using them and large-file support is enabled.
And if using ftello(), then we should probably use fseeko() as well, for
consistency if nothing else.
Maciej
