compare strings, strcmp

[Robert Osborne]

In article <11605 at smoke.BRL.MIL> gwyn at brl.arpa (Doug Gwyn) writes:
>In article <4463 at blake.acs.washington.edu> jimli at blake.acs.washington.edu (Jimmy Li) writes:
>>char array[10000][200];
>>What is the fastest way to sort this array?
>
>Dump it into an external file and invoke the system sort utility on the file.
This is a REALLY bad way of sorting an array this big.  Write ~2M to disk,
perform a system call (a fork of at least 2M) which reads ~2M from disk,
sorts it, and writes ~2M back to disk, then read ~2M from disk.  He asked
for the FASTEST way, this shouldn't even have be given as an option.

>You could also use qsort(), [...]
                    ^^^^^^^
Probably your best bet!  Use Doug's macro (below) for the compare
function.  Note the problem some qsort()'s have with "nearly sorted" data.
If you REALLY need speed implement a sort of your own, BUT only
if qsort() isn't fast enough (it should be).

>but this is such a ridiculously large amount
>of storage to statically allocate that you should be thinking of alternatives.
Maybe all his program *does* is work with 10000 character strings of length
200 :-).  Why calloc this space as the first line of your main?

>#define StrEq( a, b ) (*(a) == *(b) && strcmp( a, b ) == 0) /* UNSAFE */
This is a great macro mind if I use it?
But I see it has started another bout of comp.lang.c.morons, shame on
you Doug :-)

Rob.
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