strncopy.c   [plain text]

/***********************************************************************
*                                                                      *
*               This software is part of the ast package               *
*           Copyright (c) 1985-2007 AT&T Knowledge Ventures            *
*                      and is licensed under the                       *
*                  Common Public License, Version 1.0                  *
*                      by AT&T Knowledge Ventures                      *
*                                                                      *
*                A copy of the License is available at                 *
*            http://www.opensource.org/licenses/cpl1.0.txt             *
*         (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9)         *
*                                                                      *
*              Information and Software Systems Research               *
*                            AT&T Research                             *
*                           Florham Park NJ                            *
*                                                                      *
*                 Glenn Fowler <gsf@research.att.com>                  *
*                  David Korn <dgk@research.att.com>                   *
*                   Phong Vo <kpv@research.att.com>                    *
*                                                                      *
***********************************************************************/
#pragma prototyped

#include <ast.h>

/*
 * copy up to n bytes of string f into t
 * trailing 0 always added to t, even if n==0
 * pointer to the copied 0 returned
 */

char*
strncopy(register char* t, register const char* f, size_t n)
{
	register char*	e = t + n - 1;

	do
	{
		if (t >= e)
		{
			*t = 0;
			return t;
		}
	} while (*t++ = *f++);
	return t - 1;
}