date and time created 91/04/12 13:40:31 by bostic

[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);
}