xref: /original-bsd/lib/libc/gen/pwcache.c (revision 3b6250d9)
1 /*
2  * Copyright (c) 1989 The Regents of the University of California.
3  * All rights reserved.
4  *
5  * %sccs.include.redist.c%
6  */
7 
8 #if defined(LIBC_SCCS) && !defined(lint)
9 static char sccsid[] = "@(#)pwcache.c	5.4 (Berkeley) 06/01/90";
10 #endif /* LIBC_SCCS and not lint */
11 
12 #include <sys/types.h>
13 #include <utmp.h>
14 #include <pwd.h>
15 #include <grp.h>
16 #include <stdio.h>
17 
18 #define	NCACHE	64			/* power of 2 */
19 #define	MASK	NCACHE - 1		/* bits to store with */
20 
21 static	int pwopen = 0;
22 static	int gropen = 0;
23 
24 char *
25 user_from_uid(uid, nouser)
26 	uid_t uid;
27 	int nouser;
28 {
29 	static struct ncache {
30 		uid_t	uid;
31 		char	name[UT_NAMESIZE + 1];
32 	} c_uid[NCACHE];
33 	static char nbuf[15];		/* 32 bits == 10 digits */
34 	register struct passwd *pw;
35 	register struct ncache *cp;
36 
37 	cp = c_uid + (uid & MASK);
38 	if (cp->uid != uid || !*cp->name) {
39 		if (pwopen == 0) {
40 			setpassent(1);
41 			pwopen++;
42 		}
43 		if (!(pw = getpwuid(uid))) {
44 			if (nouser)
45 				return((char *)NULL);
46 			(void)sprintf(nbuf, "%u", uid);
47 			return(nbuf);
48 		}
49 		cp->uid = uid;
50 		(void)strncpy(cp->name, pw->pw_name, UT_NAMESIZE);
51 		cp->name[UT_NAMESIZE] = '\0';
52 	}
53 	return(cp->name);
54 }
55 
56 char *
57 group_from_gid(gid, nogroup)
58 	gid_t gid;
59 	int nogroup;
60 {
61 	static struct ncache {
62 		gid_t	gid;
63 		char	name[UT_NAMESIZE];
64 	} c_gid[NCACHE];
65 	static char nbuf[15];		/* 32 bits == 10 digits */
66 	register struct group *gr;
67 	register struct ncache *cp;
68 
69 	cp = c_gid + (gid & MASK);
70 	if (cp->gid != gid || !*cp->name) {
71 		if (gropen == 0) {
72 			setgroupent(1);
73 			gropen++;
74 		}
75 		if (!(gr = getgrgid(gid))) {
76 			if (nogroup)
77 				return((char *)NULL);
78 			(void)sprintf(nbuf, "%u", gid);
79 			return(nbuf);
80 		}
81 		cp->gid = gid;
82 		(void)strncpy(cp->name, gr->gr_name, UT_NAMESIZE);
83 		cp->name[UT_NAMESIZE] = '\0';
84 	}
85 	return(cp->name);
86 }
87