my previous version was wrong; this one is right

[unix-history] / usr / src / lib / libc / string / strncpy.c

/*-
 * Copyright (c) 1990 The Regents of the University of California.
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Chris Torek.
 *
 * %sccs.include.redist.c%
 */

#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)strncpy.c	5.6 (Berkeley) %G%";
#endif /* LIBC_SCCS and not lint */

#include <sys/cdefs.h>
#include <string.h>

/*
 * Copy src to dst, truncating or null-padding to always copy n bytes.
 * Return dst.
 */
char *
strncpy(dst, src, n)
	char *dst;
	const char *src;
	register size_t n;
{
	if (n != 0) {
		register char *d = dst;
		register const char *s = src;

		do {
			if ((*d++ = *s++) == 0) {
				/* NUL pad the remaining n-1 bytes */
				while (--n != 0)
					*d++ = 0;
				break;
			}
		} while (--n != 0);
	}
	return (dst);
}