util.subproj/pwcache.c

   1 /*
   2  * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * Portions Copyright (c) 1999 Apple Computer, Inc.  All Rights
   7  * Reserved.  This file contains Original Code and/or Modifications of
   8  * Original Code as defined in and that are subject to the Apple Public
   9  * Source License Version 1.1 (the "License").  You may not use this file
  10  * except in compliance with the License.  Please obtain a copy of the
  11  * License at http://www.apple.com/publicsource and read it before using
  12  * this file.
  13  *
  14  * The Original Code and all software distributed under the License are
  15  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  16  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  17  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE OR NON- INFRINGEMENT.  Please see the
  19  * License for the specific language governing rights and limitations
  20  * under the License.
  21  *
  22  * @APPLE_LICENSE_HEADER_END@
  23  */
  24 /*
  25  * Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved
  26  *
  27  * Copyright (c) 1989, 1993
  28  *      The Regents of the University of California.  All rights reserved.
  29  *
  30  * The NEXTSTEP Software License Agreement specifies the terms
  31  * and conditions for redistribution.
  32  *
  33  *      @(#)pwcache.c   8.1 (Berkeley) 6/4/93
  34  */
  35
  36
  37 #include <sys/types.h>
  38
  39 #include <grp.h>
  40 #include <pwd.h>
  41 #include <stdio.h>
  42 #include <utmp.h>
  43
  44 #define NCACHE  64                      /* power of 2 */
  45 #define MASK    NCACHE - 1              /* bits to store with */
  46
  47 char *
  48 user_from_uid(uid, nouser)
  49         uid_t uid;
  50         int nouser;
  51 {
  52         static struct ncache {
  53                 uid_t   uid;
  54                 char    name[UT_NAMESIZE + 1];
  55         } c_uid[NCACHE];
  56         static int pwopen;
  57         static char nbuf[15];           /* 32 bits == 10 digits */
  58         register struct passwd *pw;
  59         register struct ncache *cp;
  60
  61         cp = c_uid + (uid & MASK);
  62         if (cp->uid != uid || !*cp->name) {
  63                 if (pwopen == 0) {
  64                         setpassent(1);
  65                         pwopen = 1;
  66                 }
  67                 if ((pw = getpwuid(uid)) == NULL) {
  68                         if (nouser)
  69                                 return (NULL);
  70                         (void)snprintf(nbuf, sizeof(nbuf), "%u", uid);
  71                         return (nbuf);
  72                 }
  73                 cp->uid = uid;
  74                 (void)strncpy(cp->name, pw->pw_name, UT_NAMESIZE);
  75                 cp->name[UT_NAMESIZE] = '\0';
  76         }
  77         return (cp->name);
  78 }
  79
  80 char *
  81 group_from_gid(gid, nogroup)
  82         gid_t gid;
  83         int nogroup;
  84 {
  85         static struct ncache {
  86                 gid_t   gid;
  87                 char    name[UT_NAMESIZE + 1];
  88         } c_gid[NCACHE];
  89         static int gropen;
  90         static char nbuf[15];           /* 32 bits == 10 digits */
  91         struct group *gr;
  92         struct ncache *cp;
  93
  94         cp = c_gid + (gid & MASK);
  95         if (cp->gid != gid || !*cp->name) {
  96                 if (gropen == 0) {
  97                         setgroupent(1);
  98                         gropen = 1;
  99                 }
 100                 if ((gr = getgrgid(gid)) == NULL) {
 101                         if (nogroup)
 102                                 return (NULL);
 103                         (void)snprintf(nbuf, sizeof(nbuf), "%u", gid);
 104                         return (nbuf);
 105                 }
 106                 cp->gid = gid;
 107                 (void)strncpy(cp->name, gr->gr_name, UT_NAMESIZE);
 108                 cp->name[UT_NAMESIZE] = '\0';
 109         }
 110         return (cp->name);
 111 }