"John Reye" <jononanon@googlemail.com> wrote in message
news:d965f1e6-f918-4c5b-88f8-b5c09644faef@f5g2000vby.googlegroups.com...
> Hi,
>
> recently I learned that various "standard C library" functions have
> deficiencies in terms of high performance.
> Examples include the return values of fgets(), strcpy(), strcat()
> (thanks Eric Sosman for mentioning the last 2)
>
> Example: char * strcat ( char * destination, const char *
> source );
> Return Value: destination is returned.
>
> How useless is that! I already know the distination, in the first
> place.
> Why not return a pointer to the end of the concatenated string, or the
> size of the string. This would cost the library no extra performance
> cost whatsoever!
>
>
> Are these deficiencies _only_ string-related?

It seems that way. But no-one is bothered about it, because writing
alternative versions (thin wrappers around standard functions) is trivial:

int strcat_l(char *s,char *t,int slen,int tlen){
if (slen<0) slen=strlen(s);
if (tlen<0) tlen=strlen(t);
memcpy(s+slen,t,tlen+1);
return slen+tlen;
}

int strcpy_l(char *s,char *t,int tlen){
if (tlen<0) tlen=strlen(t);
memcpy(s,t,tlen+1);
return tlen;
}

Etc.

(In this style that I sometimes use, you can optionally supply a string
length if you know it, otherwise -1 is passed. It's not hard to make them
faster than the standard functions. (Except when the lengths aren't known;
then it would probably be better for these to just call the standard
versions, instead of messing with strlen(). But I tend to use this form for
other kinds of string processing where a standard version doesn't exist.))

--
Bartc