xref: /titanic_50/usr/src/lib/libast/common/string/strncopy.c (revision 3e14f97f673e8a630f076077de35afdd43dc1587)
1da2e3ebdSchin /***********************************************************************
2da2e3ebdSchin *                                                                      *
3da2e3ebdSchin *               This software is part of the ast package               *
4*3e14f97fSRoger A. Faulkner *          Copyright (c) 1985-2010 AT&T Intellectual Property          *
5da2e3ebdSchin *                      and is licensed under the                       *
6da2e3ebdSchin *                  Common Public License, Version 1.0                  *
77c2fbfb3SApril Chin *                    by AT&T Intellectual Property                     *
8da2e3ebdSchin *                                                                      *
9da2e3ebdSchin *                A copy of the License is available at                 *
10da2e3ebdSchin *            http://www.opensource.org/licenses/cpl1.0.txt             *
11da2e3ebdSchin *         (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9)         *
12da2e3ebdSchin *                                                                      *
13da2e3ebdSchin *              Information and Software Systems Research               *
14da2e3ebdSchin *                            AT&T Research                             *
15da2e3ebdSchin *                           Florham Park NJ                            *
16da2e3ebdSchin *                                                                      *
17da2e3ebdSchin *                 Glenn Fowler <gsf@research.att.com>                  *
18da2e3ebdSchin *                  David Korn <dgk@research.att.com>                   *
19da2e3ebdSchin *                   Phong Vo <kpv@research.att.com>                    *
20da2e3ebdSchin *                                                                      *
21da2e3ebdSchin ***********************************************************************/
22da2e3ebdSchin #pragma prototyped
23da2e3ebdSchin 
24da2e3ebdSchin #include <ast.h>
25da2e3ebdSchin 
26da2e3ebdSchin /*
27da2e3ebdSchin  * copy up to n bytes of string f into t
28da2e3ebdSchin  * trailing 0 always added to t, even if n==0
29da2e3ebdSchin  * pointer to the copied 0 returned
30da2e3ebdSchin  */
31da2e3ebdSchin 
32da2e3ebdSchin char*
strncopy(register char * t,register const char * f,size_t n)33da2e3ebdSchin strncopy(register char* t, register const char* f, size_t n)
34da2e3ebdSchin {
35da2e3ebdSchin 	register char*	e = t + n - 1;
36da2e3ebdSchin 
37da2e3ebdSchin 	do
38da2e3ebdSchin 	{
39da2e3ebdSchin 		if (t >= e)
40da2e3ebdSchin 		{
41da2e3ebdSchin 			*t = 0;
42da2e3ebdSchin 			return t;
43da2e3ebdSchin 		}
44da2e3ebdSchin 	} while (*t++ = *f++);
45da2e3ebdSchin 	return t - 1;
46da2e3ebdSchin }
47