xref: /src/usr.bin/who/who.c

/*	$NetBSD: who.c,v 1.9 2002/07/28 21:46:34 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 1.9 2002/07/28 21:46:34 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>
#ifdef SUPPORT_UTMP
#include <utmp.h>
#endif
#ifdef SUPPORT_UTMPX
#include <utmpx.h>
#endif

struct entry {
	char name[65];
	char line[65];
	char host[257];
	time_t time;
	struct entry *next;
};

static void output_labels(void);
static void who_am_i(const char *, int);
static void usage(void);
static void process(const char *, int);
#ifdef SUPPORT_UTMP
static void getentry(struct entry *, struct utmp *);
#endif
#ifdef SUPPORT_UTMPX
static void getentryx(struct entry *, struct utmpx *);
#endif
#if defined(SUPPORT_UTMPX) && defined(SUPPORT_UTMP)
static int setup(const char *);
static void adjust_size(struct entry *e);
#endif
static void print(const char *, const char *, time_t, const char *);

int main(int, char **);

static int show_term;			/* show term state */
static int show_idle;			/* show idle time */

static int maxname = 8, maxline = 8, maxhost = 16;

int
main(int argc, char **argv)
{
	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 */
	}

	switch (argc) {
	case 0:					/* who */
		if (only_current_term) {
			who_am_i(NULL, show_labels);
		} else {
			process(NULL, show_labels);
		}
		break;
	case 1:					/* who utmp_file */
		if (only_current_term) {
			who_am_i(*argv, show_labels);
		} else {
			process(*argv, show_labels);
		}
		break;
	case 2:					/* who am i */
		who_am_i(NULL, show_labels);
		break;
	default:
		usage();
		/* NOTREACHED */
	}
	exit(0);
}

#if defined(SUPPORT_UTMPX) && defined(SUPPORT_UTMP)
static void
adjust_size(struct entry *e)
{
	int max;

	if ((max = strlen(e->name)) > maxname)
		maxname = max;
	if ((max = strlen(e->line)) > maxline)
		maxline = max;
	if ((max = strlen(e->host)) > maxhost)
		maxhost = max;
}

static int
setup(const char *fname)
{
	int what = 3;

	if (fname == NULL) {
#ifdef SUPPORT_UTMPX
		setutent();
#endif
#ifdef SUPPORT_UTMP
		setutxent();
#endif
	} else {
		size_t len = strlen(fname);
		if (len == 0)
			errx(1, "Filename cannot be 0 length.");
		what = fname[len - 1] == 'x' ? 1 : 2;
		if (what == 1) {
#ifdef SUPPORT_UTMPX
			if (utmpxname(fname) == 0)
				err(1, "Cannot open `%s'", fname);
#else
			errx(1, "utmpx support not compiled in");
#endif
		} else {
#ifdef SUPPORT_UTMPX
			if (utmpname(fname) == 0)
				err(1, "Cannot open `%s'", fname);
#else
			errx(1, "utmp support not compiled in");
#endif
		}
	}
	return what;
}
#endif

static void
who_am_i(const char *fname, int show_labels)
{
#ifdef SUPPORT_UTMPX
	struct utmpx *utx;
#endif
#ifdef SUPPORT_UTMP
	struct utmp *ut;
#endif
	struct passwd *pw;
	char *p;
	char *t;
	time_t now;
#if defined(SUPPORT_UTMP) && defined(SUPPORT_UTMPX)
	int what = setup(fname);
#endif

	/* search through the utmp and find an entry for this tty */
	if ((p = ttyname(STDIN_FILENO)) != NULL) {

		/* strip any directory component */
		if ((t = strrchr(p, '/')) != NULL)
			p = t + 1;
#ifdef SUPPORT_UTMPX
		while ((what & 1) && (utx = getutxent()) != NULL)
			if (utx->ut_type == USER_PROCESS &&
			    !strcmp(utx->ut_line, p)) {
				struct entry e;
				getentryx(&e, utx);
				if (show_labels)
					output_labels();
				print(e.name, e.line, e.time, e.host);
				return;
			}
#endif
#ifdef SUPPORT_UTMP
		while ((what & 2) && (ut = getutent()) != NULL)
			if (!strcmp(ut->ut_line, p)) {
				struct entry e;
				getentry(&e, ut);
				if (show_labels)
					output_labels();
				print(e.name, e.line, e.time, e.host);
				return;
			}
#endif
	} else
		p = "tty??";

	(void)time(&now);
	pw = getpwuid(getuid());
	if (show_labels)
		output_labels();
	print(pw ? pw->pw_name : "?", p, now, "");
}

static void
process(const char *fname, int show_labels)
{
#ifdef SUPPORT_UTMPX
	struct utmpx *utx;
#endif
#ifdef SUPPORT_UTMP
	struct utmp *ut;
#endif
	struct entry *ep, *ehead = NULL;
#if defined(SUPPORT_UTMP) && defined(SUPPORT_UTMPX)
	int what = setup(fname);
	struct entry **nextp = &ehead;
#endif

#ifdef SUPPORT_UTMPX
	while ((what & 1) && (utx = getutxent()) != NULL) {
		if (fname == NULL && utx->ut_type != USER_PROCESS)
			continue;
		if ((ep = calloc(1, sizeof(struct entry))) == NULL)
			err(1, NULL);
		getentryx(ep, utx);
		*nextp = ep;
		nextp = &(ep->next);
	}
#endif

#ifdef SUPPORT_UTMP
	while ((what & 2) && (ut = getutent()) != NULL) {
		if (fname == NULL && (*ut->ut_name == '\0' ||
		    *ut->ut_line == '\0'))
			continue;
		/* Don't process entries that we have utmpx for */
		for (ep = ehead; ep != NULL; ep = ep->next) {
			if (strncmp(ep->line, ut->ut_line,
			    sizeof(ut->ut_line)) == 0)
				break;
		}
		if (ep != NULL)
			continue;
		if ((ep = calloc(1, sizeof(struct entry))) == NULL)
			err(1, NULL);
		getentry(ep, ut);
		*nextp = ep;
		nextp = &(ep->next);
	}
#endif
#if defined(SUPPORT_UTMP) && defined(SUPPORT_UTMPX)
	if (ehead != NULL) {
		struct entry *from = ehead, *save;

		ehead = NULL;
		while (from != NULL) {
			for (nextp = &ehead;
			    (*nextp) && strcmp(from->line, (*nextp)->line) > 0;
			    nextp = &(*nextp)->next)
				continue;
			save = from;
			from = from->next;
			save->next = *nextp;
			*nextp = save;
		}
	}
#endif
	if (show_labels)
		output_labels();
	for (ep = ehead; ep != NULL; ep = ep->next)
		print(ep->name, ep->line, ep->time, ep->host);
}

#ifdef SUPPORT_UTMP
static void
getentry(struct entry *e, struct utmp *up)
{
	(void)strncpy(e->name, up->ut_name, sizeof(up->ut_name));
	e->name[sizeof(e->name) - 1] = '\0';
	(void)strncpy(e->line, up->ut_line, sizeof(up->ut_line));
	e->line[sizeof(e->line) - 1] = '\0';
	(void)strncpy(e->host, up->ut_host, sizeof(up->ut_host));
	e->name[sizeof(e->host) - 1] = '\0';
	e->time = up->ut_time;
	adjust_size(e);
}
#endif

#ifdef SUPPORT_UTMPX
static void
getentryx(struct entry *e, struct utmpx *up)
{
	(void)strncpy(e->name, up->ut_name, sizeof(up->ut_name));
	e->name[sizeof(e->name) - 1] = '\0';
	(void)strncpy(e->line, up->ut_line, sizeof(up->ut_line));
	e->line[sizeof(e->line) - 1] = '\0';
	(void)strncpy(e->host, up->ut_host, sizeof(up->ut_host));
	e->name[sizeof(e->host) - 1] = '\0';
	e->time = (time_t)up->ut_tv.tv_sec;
	adjust_size(e);
}
#endif


static void
print(const char *name, const char *line, time_t t, const char *host)
{
	struct stat sb;
	char state;
	static time_t now = 0;
	time_t idle;

	state = '?';
	idle = 0;

	if (show_term || show_idle) {
		if (now == 0)
			time(&now);

		if (stat(line, &sb) == 0) {
			state = (sb.st_mode & 020) ? '+' : '-';
			idle = now - sb.st_atime;
		}

	}

	(void)printf("%-*.*s ", maxname, maxname, name);

	if (show_term) {
		(void)printf("%c ", state);
	}

	(void)printf("%-*.*s ", maxline, maxline, line);
	(void)printf("%.12s ", ctime(&t) + 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 (*host)
		printf("\t(%.*s)", maxhost, host);
	(void)putchar('\n');
}

static void
output_labels()
{
	(void)printf("%-*.*s ", maxname, maxname, "USER");

	if (show_term)
		(void)printf("S ");

	(void)printf("%-*.*s ", maxline, maxline, "LINE");
	(void)printf("WHEN         ");

	if (show_idle)
		(void)printf("IDLE  ");

	(void)printf("\t%.*s", maxhost, "FROM");

	(void)putchar('\n');
}

static void
usage()
{
	(void)fprintf(stderr, "Usage: %s [-mTuH] [ file ]\n       %s am i\n",
	    getprogname(), getprogname());
	exit(1);
}