114 lines
3.2 KiB
C
114 lines
3.2 KiB
C
/* $OpenBSD: users.c,v 1.15 2021/07/12 15:09:20 beck Exp $ */
|
|
/* $NetBSD: users.c,v 1.5 1994/12/20 15:58:19 jtc Exp $ */
|
|
|
|
/*
|
|
* Copyright (c) 1980, 1987, 1993
|
|
* The Regents of the University of California. All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
* 3. 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 BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
|
|
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
|
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
* SUCH DAMAGE.
|
|
*/
|
|
|
|
#include <sys/types.h>
|
|
|
|
#include <err.h>
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
#include <unistd.h>
|
|
#include <utmp.h>
|
|
|
|
typedef char namebuf[UT_NAMESIZE];
|
|
|
|
int scmp(const void *, const void *);
|
|
|
|
int
|
|
main(int argc, char *argv[])
|
|
{
|
|
namebuf *names = NULL;
|
|
int ncnt = 0;
|
|
int nmax = 0;
|
|
int cnt;
|
|
struct utmp utmp;
|
|
int ch;
|
|
|
|
if (unveil(_PATH_UTMP, "r") == -1)
|
|
err(1, "unveil %s", _PATH_UTMP);
|
|
if (pledge("stdio rpath", NULL) == -1)
|
|
err(1, "pledge");
|
|
|
|
while ((ch = getopt(argc, argv, "")) != -1)
|
|
switch(ch) {
|
|
case '?':
|
|
default:
|
|
(void)fprintf(stderr, "usage: users\n");
|
|
exit(1);
|
|
}
|
|
argc -= optind;
|
|
argv += optind;
|
|
|
|
if (!freopen(_PATH_UTMP, "r", stdin)) {
|
|
err(1, "can't open %s", _PATH_UTMP);
|
|
/* NOTREACHED */
|
|
}
|
|
|
|
while (fread((char *)&utmp, sizeof(utmp), 1, stdin) == 1) {
|
|
if (*utmp.ut_name) {
|
|
if (ncnt >= nmax) {
|
|
size_t newmax = nmax + 32;
|
|
namebuf *newnames;
|
|
|
|
newnames = reallocarray(names, newmax,
|
|
sizeof(*names));
|
|
|
|
if (newnames == NULL) {
|
|
err(1, NULL);
|
|
/* NOTREACHED */
|
|
}
|
|
names = newnames;
|
|
nmax = newmax;
|
|
}
|
|
|
|
(void)strncpy(names[ncnt], utmp.ut_name, UT_NAMESIZE);
|
|
++ncnt;
|
|
}
|
|
}
|
|
|
|
if (ncnt) {
|
|
qsort(names, ncnt, UT_NAMESIZE, scmp);
|
|
(void)printf("%.*s", UT_NAMESIZE, names[0]);
|
|
for (cnt = 1; cnt < ncnt; ++cnt)
|
|
if (strncmp(names[cnt], names[cnt - 1], UT_NAMESIZE))
|
|
(void)printf(" %.*s", UT_NAMESIZE, names[cnt]);
|
|
(void)printf("\n");
|
|
}
|
|
exit(0);
|
|
}
|
|
|
|
int
|
|
scmp(const void *p, const void *q)
|
|
{
|
|
return(strncmp((char *) p, (char *) q, UT_NAMESIZE));
|
|
}
|