On Aug 6, 2013, at 3:57 PM, Dirk Jagdmann <d...@cubic.org> wrote:
>> If not, would an lseek() followed by a read() do just as well?
>
> No. lseek() and read() modify the file position/offset. pread() however does
> *not* modify it. So to emulate pread() you would need something like:
If you do an absolute lseek() before each read(), and no other code uses the
file descriptor, an lseek() followed by a read() *would* do as well. The only
things the routine in question does with the FD (which is static to the
routine) are
(attempt to) open it if it's not already open;
read it with
ret = pread(fd, buf, sizeof(buf)-1, 0);
if (ret <= 0)
return FALSE;
so that could be replaced by
if (lseek(fd, 0, SEEK_SET) == -1)
return FALSE;
ret = read(fd, buf, sizeof(buf)-1);
if (ret <= 0)
return FALSE;
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