BSD 4_3_Reno release

[unix-history] / usr / src / lib / libutil / pwcache.c

/*
* Copyright (c) 1989 The Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms are permitted
* provided that: (1) source distributions retain this entire copyright
* notice and comment, and (2) distributions including binaries display
* the following acknowledgement:  ``This product includes software
* developed by the University of California, Berkeley and its contributors''
* in the documentation or other materials provided with the distribution
* and in all advertising materials mentioning features or use of this
* software. Neither the name of the University nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/

#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)pwcache.c   5.4 (Berkeley) 6/1/90";
#endif /* LIBC_SCCS and not lint */

#include <sys/types.h>
#include <utmp.h>
#include <pwd.h>
#include <grp.h>
#include <stdio.h>

#define NCACHE  64                      /* power of 2 */
#define MASK    NCACHE - 1              /* bits to store with */

static  int pwopen = 0;
static  int gropen = 0;

char *
user_from_uid(uid, nouser)
       uid_t uid;
       int nouser;
{
       static struct ncache {
               uid_t   uid;
               char    name[UT_NAMESIZE + 1];
       } c_uid[NCACHE];
       static char nbuf[15];           /* 32 bits == 10 digits */
       register struct passwd *pw;
       register struct ncache *cp;

       cp = c_uid + (uid & MASK);
       if (cp->uid != uid || !*cp->name) {
               if (pwopen == 0) {
                       setpassent(1);
                       pwopen++;
               }
               if (!(pw = getpwuid(uid))) {
                       if (nouser)
                               return((char *)NULL);
                       (void)sprintf(nbuf, "%u", uid);
                       return(nbuf);
               }
               cp->uid = uid;
               (void)strncpy(cp->name, pw->pw_name, UT_NAMESIZE);
               cp->name[UT_NAMESIZE] = '\0';
       }
       return(cp->name);
}

char *
group_from_gid(gid, nogroup)
       gid_t gid;
       int nogroup;
{
       static struct ncache {
               gid_t   gid;
               char    name[UT_NAMESIZE];
       } c_gid[NCACHE];
       static char nbuf[15];           /* 32 bits == 10 digits */
       register struct group *gr;
       register struct ncache *cp;

       cp = c_gid + (gid & MASK);
       if (cp->gid != gid || !*cp->name) {
               if (gropen == 0) {
                       setgroupent(1);
                       gropen++;
               }
               if (!(gr = getgrgid(gid))) {
                       if (nogroup)
                               return((char *)NULL);
                       (void)sprintf(nbuf, "%u", gid);
                       return(nbuf);
               }
               cp->gid = gid;
               (void)strncpy(cp->name, gr->gr_name, UT_NAMESIZE);
               cp->name[UT_NAMESIZE] = '\0';
       }
       return(cp->name);
}