>>37
You don't need that shit, it either works or doesn't. Those error messages broken down:
<stdin>:19:2: error: implicit declaration of function 'getopt'
Your system is not POSIX.
getopt is in
unistd.h.
(
http://pubs.opengroup.org/onlinepubs/000095399/functions/getopt.html)
<stdin>:27:5: error: 'optind' undeclared (first use in this function)
Same thing.
<stdin>:48:3: error: suggest parentheses around assignment used as truth value
Not an error.
<stdin>:49:32: error: comparison between signed and unsigned integer expressions
Doesn't matter, it's only checking for equality between however many bytes read and written.
I should've stopped at the first error; compiling a POSIX utility on a non-POSIX system is already doing it wrong.
>>37
It's an inherently serial process. The only speedup possible is by reading/writing bigger chunks.