ref: a4a975e8ac706cc2d9ef954c250b7ae4dd2e0e08
dir: /sys/src/libc/port/strncat.c/
#include <u.h>
#include <libc.h>
char*
strncat(char *s1, char *s2, long n)
{
char *os1;
os1 = s1;
while(*s1++)
;
s1--;
while(*s1++ = *s2++)
if(--n < 0) {
s1[-1] = 0;
break;
}
return os1;
}