xref: /csrg-svn/lib/libc/gen/pwcache.c (revision 40263)
1*40263Sbostic /*
2*40263Sbostic  * Copyright (c) 1989 The Regents of the University of California.
3*40263Sbostic  * All rights reserved.
4*40263Sbostic  *
5*40263Sbostic  * Redistribution and use in source and binary forms are permitted
6*40263Sbostic  * provided that the above copyright notice and this paragraph are
7*40263Sbostic  * duplicated in all such forms and that any documentation,
8*40263Sbostic  * advertising materials, and other materials related to such
9*40263Sbostic  * distribution and use acknowledge that the software was developed
10*40263Sbostic  * by the University of California, Berkeley.  The name of the
11*40263Sbostic  * University may not be used to endorse or promote products derived
12*40263Sbostic  * from this software without specific prior written permission.
13*40263Sbostic  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
14*40263Sbostic  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
15*40263Sbostic  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
16*40263Sbostic  */
17*40263Sbostic 
18*40263Sbostic #if defined(LIBC_SCCS) && !defined(lint)
19*40263Sbostic static char sccsid[] = "@(#)pwcache.c	5.1 (Berkeley) 03/05/90";
20*40263Sbostic #endif /* LIBC_SCCS and not lint */
21*40263Sbostic 
22*40263Sbostic #include <sys/types.h>
23*40263Sbostic #include <utmp.h>
24*40263Sbostic #include <pwd.h>
25*40263Sbostic #include <grp.h>
26*40263Sbostic 
27*40263Sbostic #define	NCACHE	64			/* power of 2 */
28*40263Sbostic #define	MASK	NCACHE - 1		/* bits to store with */
29*40263Sbostic 
30*40263Sbostic char *
31*40263Sbostic user_from_uid(uid)
32*40263Sbostic 	uid_t uid;
33*40263Sbostic {
34*40263Sbostic 	static struct ncache {
35*40263Sbostic 		uid_t	uid;
36*40263Sbostic 		char	name[UT_NAMESIZE + 1];
37*40263Sbostic 	} c_uid[NCACHE];
38*40263Sbostic 	static char nbuf[15];		/* 32 bits == 10 digits */
39*40263Sbostic 	register struct passwd *pw;
40*40263Sbostic 	register struct ncache *cp;
41*40263Sbostic 
42*40263Sbostic 	cp = c_uid + (uid & MASK);
43*40263Sbostic 	if (cp->uid != uid || !*cp->name) {
44*40263Sbostic 		/* if can't find owner, use user id instead */
45*40263Sbostic 		if (!(pw = getpwuid(uid))) {
46*40263Sbostic 			(void)sprintf(nbuf, "%u", uid);
47*40263Sbostic 			return(nbuf);
48*40263Sbostic 		}
49*40263Sbostic 		cp->uid = uid;
50*40263Sbostic 		(void)strncpy(cp->name, pw->pw_name, UT_NAMESIZE);
51*40263Sbostic 		cp->name[UT_NAMESIZE] = '\0';
52*40263Sbostic 	}
53*40263Sbostic 	return(cp->name);
54*40263Sbostic }
55*40263Sbostic 
56*40263Sbostic char *
57*40263Sbostic group_from_gid(gid)
58*40263Sbostic 	gid_t gid;
59*40263Sbostic {
60*40263Sbostic 	static struct ncache {
61*40263Sbostic 		gid_t	gid;
62*40263Sbostic 		char	name[UT_NAMESIZE];
63*40263Sbostic 	} c_gid[NCACHE];
64*40263Sbostic 	static char nbuf[15];		/* 32 bits == 10 digits */
65*40263Sbostic 	register struct group *gr;
66*40263Sbostic 	register struct ncache *cp;
67*40263Sbostic 
68*40263Sbostic 	cp = c_gid + (gid & MASK);
69*40263Sbostic 	if (cp->gid != gid || !*cp->name) {
70*40263Sbostic 		/* if can't find group, use group id instead */
71*40263Sbostic 		if (!(gr = getgrgid(gid))) {
72*40263Sbostic 			(void)sprintf(nbuf, "%u", gid);
73*40263Sbostic 			return(nbuf);
74*40263Sbostic 		}
75*40263Sbostic 		cp->gid = gid;
76*40263Sbostic 		(void)strncpy(cp->name, gr->gr_name, UT_NAMESIZE);
77*40263Sbostic 		cp->name[UT_NAMESIZE] = '\0';
78*40263Sbostic 	}
79*40263Sbostic 	return(cp->name);
80*40263Sbostic }
81