[ILUG] C string concat question revisited

[Conor Daly]

On Fri, May 04, 2001 at 01:11:07PM +0100 or thereabouts, kevin lyda wrote:
> 
> #define STRSIZE 80
> char *
> strdup2(char *s1, char *s2)
> {
>     char *s;
> 
>     if ((s=(char *)malloc(STRSIZE + 1)) == NULL) {
> 	return NULL;
>     }
>     /* the following initialises the string.  s[0]=0;s[STRSIZE]=0; *
>      * would work too.                                             */
>     memset(s, 0, STRSIZE + 1);
>     /* from here on in we don't let str* routines near s[STRSIZE]  *
>      * so we know it will stay 0.                                  */
>     strncpy(s, s1, STRSIZE);
>     strncat(s, s2, STRSIZE - strlen(s));
>     return s;
> }
> 
> strlen works by counting chars until it reaches '\0'.  therefore don't use
>     it if you're not sure the string is null terminated.
> sizeof(char) is not required.
> 
> kevin

Some while back, Kevin posted the above which allocates *new* memory for a
string s which contains s1 and s2 (useage: s = strdup2(s1, s2); ).  
Now, I have a string struct.s which, as the name suggests, is part of an 
already allocated struct.  If I want to set *that* to contain s1 and s2, can 
I use the above ( struct.s = strdup2(s1, s2); ) or do I just use strncpy() 
and strncat()?

Conor
-- 
Conor Daly 
Met Eireann, Glasnevin Hill, Dublin 9, Ireland
Ph +353 1 8064276 Fax +353 1 8064275
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