BSD 4_3_Reno release

[unix-history] / usr / src / usr.bin / users / users.c

/*
* Copyright (c) 1980, 1987 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.
*/

#ifndef lint
char copyright[] =
"@(#) Copyright (c) 1980, 1987 Regents of the University of California.\n\
All rights reserved.\n";
#endif /* not lint */

#ifndef lint
static char sccsid[] = "@(#)users.c     5.9 (Berkeley) 6/1/90";
#endif /* not lint */

#include <sys/types.h>
#include <errno.h>
#include <utmp.h>
#include <stdio.h>

#define MAXUSERS        200

main()
{
       register int cnt, ncnt;
       struct utmp utmp;
       char names[MAXUSERS][UT_NAMESIZE];
       int scmp();

       if (!freopen(_PATH_UTMP, "r", stdin)) {
               (void)fprintf(stderr, "users: can't open %s.\n", _PATH_UTMP);
               exit(1);
       }
       for (ncnt = 0;
           fread((char *)&utmp, sizeof(utmp), 1, stdin) == 1;)
               if (*utmp.ut_name) {
                       if (ncnt == MAXUSERS) {
                               (void)fprintf(stderr,
                                   "users: too many users.\n");
                               break;
                       }
                       (void)strncpy(names[ncnt], utmp.ut_name, UT_NAMESIZE);
                       ++ncnt;
               }

       if (ncnt) {
               qsort(names, ncnt, UT_NAMESIZE, scmp);
               (void)printf("%s", names[0]);
               for (cnt = 1; cnt < ncnt; ++cnt) {
                       while (cnt < ncnt - 1 &&
                           !strncmp(names[cnt], names[cnt + 1], UT_NAMESIZE))
                               ++cnt;
                       (void)printf(" %.*s", UT_NAMESIZE, names[cnt]);
               }
               (void)printf("\n");
       }
       exit(0);
}

scmp(p, q)
       char *p, *q;
{
       return(strcmp(p, q));
}