Re: Total Newbie Backward Compat Question

In article <8tydnTOyDO1LT0XaRVnyjAA@[EMAIL PROTECTED]
>, rjh@[EMAIL PROTECTED]
 says...

[ ... ]

> But to answer your question: strncpy is (wrongly) seen as a "safe
strcpy" 
> (it isn't), it always writes n bytes (which lots of people don't
realise), 
> and - as Anand pointed out - it's quite easy to find yourself with a 
> non-terminated 'string' (which is Very Bad Indeed unless you realise and

> intend it and know how to deal with it). The strtok function can't
process 
> more than one string at a time - that is, you can't start processing one

> string, process another, and then return to the first, because it 
> maintains state internally. And of course Anand is right that it isn't 
> thread-safe (for the same underlying reason).

Actually, strtok may or may not be thread-safe, depending on its 
implementation. It does take some extra work (one variable in thread 
local storage) to make it thread safe, but that's not terribly 
difficult.

More problematic under some cir***stances, is that attempting to use 
strtok on a string literal gives undefined results. This is rarely a 
problem in real life, but can be a bit more of one when/if you want to 
write a small demonstration of how it's supposed to to work, what it's 
supposed to do, etc. The cure is to use an array of char initialized 
from the string literal instead of attempting to use the string literal 
directly:

char *x="This is a string";
char y[] = "This is a string too";

strtok(x, " ");	// undefined behavior.

strtok(y, " ");	// defined behavior.

-- 
    Later,
    Jerry.

The universe is a figment of its own imagination.