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#include "syshdrs.h"
#ifdef PRAGMA_HDRSTOP
# pragma hdrstop
#endif
/*
* Concatenate src on the end of dst. The resulting string will have at most
* n-1 characters, not counting the NUL terminator which is always appended
* unlike strncat. The other big difference is that strncpy uses n as the
* max number of characters _appended_, while this routine uses n to limit
* the overall length of dst.
*
* This routine also differs in that it returns a pointer to the end
* of the buffer, instead of strncat which returns a pointer to the start.
*/
char *
Strnpcat(char *const dst, const char *const src, size_t n)
{
register size_t i;
register char *d;
register const char *s;
register char c;
char *ret;
if (n != 0 && ((i = strlen(dst)) < (n - 1))) {
d = dst + i;
s = src;
/* If they specified a maximum of n characters, use n - 1 chars to
* hold the copy, and the last character in the array as a NUL.
* This is the difference between the regular strncpy routine.
* strncpy doesn't guarantee that your new string will have a
* NUL terminator, but this routine does.
*/
for (++i; i<n; i++) {
c = *s++;
if (c == '\0') {
ret = d; /* Return ptr to end byte. */
*d++ = c;
#if (STRNP_ZERO_PAD == 1)
/* Pad with zeros. */
for (; i<n; i++)
*d++ = 0;
#endif /* STRNP_ZERO_PAD */
return ret;
}
*d++ = c;
}
/* If we get here, then we have a full string, with n - 1 characters,
* so now we NUL terminate it and go home.
*/
*d = 0;
return (d); /* Return ptr to end byte. */
}
return (dst);
} /* Strnpcat */
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