NetBSD/usr.bin/who/who.c
christos 6653fa8b3c How did this bug survive for so long? 'who am i' was busted because
it checked for valid utmp entries with usr.ut_name != NULL which can
never happen ofcourse, instead of usr.ut_name[0] != '\0'
1999-07-17 16:41:44 +00:00

275 lines
6.3 KiB
C

/* $NetBSD: who.c,v 1.8 1999/07/17 16:41:44 christos Exp $ */
/*
* Copyright (c) 1989, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Michael Fischbein.
*
* 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. 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/cdefs.h>
#ifndef lint
__COPYRIGHT(
"@(#) Copyright (c) 1989, 1993\n\
The Regents of the University of California. All rights reserved.\n");
#endif /* not lint */
#ifndef lint
#if 0
static char sccsid[] = "@(#)who.c 8.1 (Berkeley) 6/6/93";
#endif
__RCSID("$NetBSD: who.c,v 1.8 1999/07/17 16:41:44 christos Exp $");
#endif /* not lint */
#include <sys/types.h>
#include <sys/stat.h>
#include <err.h>
#include <locale.h>
#include <pwd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include <utmp.h>
void output __P((struct utmp *));
void output_labels __P((void));
void who_am_i __P((FILE *));
FILE *file __P((char *));
void usage __P((void));
int show_term; /* show term state */
int show_idle; /* show idle time */
int main __P((int, char **));
int
main(argc, argv)
int argc;
char **argv;
{
struct utmp usr;
FILE *ufp;
int c, only_current_term, show_labels;
setlocale(LC_ALL, "");
only_current_term = show_term = show_idle = show_labels = 0;
while ((c = getopt(argc, argv, "mTuH")) != -1) {
switch (c) {
case 'm':
only_current_term = 1;
break;
case 'T':
show_term = 1;
break;
case 'u':
show_idle = 1;
break;
case 'H':
show_labels = 1;
break;
default:
usage();
/* NOTREACHED */
}
}
argc -= optind;
argv += optind;
if (chdir("/dev")) {
err(1, "cannot change directory to /dev");
/* NOTREACHED */
}
if (show_labels)
output_labels();
switch (argc) {
case 0: /* who */
ufp = file(_PATH_UTMP);
if (only_current_term) {
who_am_i(ufp);
} else {
/* only entries with both name and line fields */
while (fread((char *)&usr, sizeof(usr), 1, ufp) == 1)
if (*usr.ut_name && *usr.ut_line)
output(&usr);
}
break;
case 1: /* who utmp_file */
ufp = file(*argv);
if (only_current_term) {
who_am_i(ufp);
} else {
/* all entries */
while (fread((char *)&usr, sizeof(usr), 1, ufp) == 1)
output(&usr);
}
break;
case 2: /* who am i */
ufp = file(_PATH_UTMP);
who_am_i(ufp);
break;
default:
usage();
/* NOTREACHED */
}
exit(0);
}
void
who_am_i(ufp)
FILE *ufp;
{
struct utmp usr;
struct passwd *pw;
char *p;
char *t;
/* search through the utmp and find an entry for this tty */
if ((p = ttyname(0)) != NULL) {
/* strip any directory component */
if ((t = strrchr(p, '/')) != NULL)
p = t + 1;
while (fread((char *)&usr, sizeof(usr), 1, ufp) == 1)
if (usr.ut_name[0] != '\0' &&
!strcmp(usr.ut_line, p)) {
output(&usr);
return;
}
/* well, at least we know what the tty is */
(void)strncpy(usr.ut_line, p, UT_LINESIZE);
} else
(void)strcpy(usr.ut_line, "tty??");
pw = getpwuid(getuid());
(void)strncpy(usr.ut_name, pw ? pw->pw_name : "?", UT_NAMESIZE);
(void)time(&usr.ut_time);
*usr.ut_host = '\0';
output(&usr);
}
void
output(up)
struct utmp *up;
{
struct stat sb;
char line[sizeof (up->ut_line) + 1];
char state;
static time_t now = 0;
time_t idle;
state = '?';
idle = 0;
if (show_term || show_idle) {
if (now == 0)
time(&now);
strncpy(line, up->ut_line, sizeof (up->ut_line));
line[sizeof (up->ut_line)] = '\0';
if (stat(line, &sb) == 0) {
state = (sb.st_mode & 020) ? '+' : '-';
idle = now - sb.st_atime;
}
}
(void)printf("%-*.*s ", (int)UT_NAMESIZE, (int)UT_NAMESIZE, up->ut_name);
if (show_term) {
(void)printf("%c ", state);
}
(void)printf("%-*.*s ", (int)UT_LINESIZE, (int)UT_LINESIZE, up->ut_line);
(void)printf("%.12s ", ctime(&up->ut_time) + 4);
if (show_idle) {
if (idle < 60)
(void)printf(" . ");
else if (idle < (24 * 60 * 60))
(void)printf("%02ld:%02ld ",
(long)(idle / (60 * 60)),
(long)(idle % (60 * 60)) / 60);
else
(void)printf(" old ");
}
if (*up->ut_host)
printf("\t(%.*s)", (int)UT_HOSTSIZE, up->ut_host);
(void)putchar('\n');
}
void
output_labels()
{
(void)printf("%-*.*s ", (int)UT_NAMESIZE, (int)UT_NAMESIZE, "USER");
if (show_term)
(void)printf("S ");
(void)printf("%-*.*s ", (int)UT_LINESIZE, (int)UT_LINESIZE, "LINE");
(void)printf("WHEN ");
if (show_idle)
(void)printf("IDLE ");
(void)printf("\t%.*s", (int)UT_HOSTSIZE, "FROM");
(void)putchar('\n');
}
FILE *
file(name)
char *name;
{
FILE *ufp;
if (!(ufp = fopen(name, "r"))) {
err(1, "%s", name);
/* NOTREACHED */
}
return (ufp);
}
void
usage()
{
(void)fprintf(stderr, "usage: who [-mTuH] [ file ]\n who am i\n");
exit(1);
}