[ILUG] C string concat question revisited

[Dave Neary]

Conor Daly wrote:
> 
> 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()?

No reason why you can't, if you're sure it'll work :)

An alternate (possibly slightly less messy) solution would be

char * mystrdupcat(char *s1, char *s2)
/* Note all functions starting with "str" are forbidden by the standard
*/
{
	char *string;
	int l1, l2;

	l1 = strlen(s1);
	l2 = strlen(s2);

	str = malloc(l1 + l2 + 1);
	/* Error checking stuff... */

	strncpy(str, s1, l1 + 1); /* Copies the '\0' terminator'
	strncat(str, s2, l2 + 1); /* Over-writes '\0' and writes its own */

	return str;
}

Cheers,
Dave.

-- 
David Neary,               E-Mail dave.neary at palamon.ie
Palamon Technologies Ltd.  Phone +353-1-634-5059