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