freebsd-dev/usr.bin/who/who.c
1999-08-28 01:08:13 +00:00

160 lines
4.4 KiB
C

/*
* 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.
*/
#ifndef lint
static const char 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
static const char rcsid[] =
"$FreeBSD$";
#endif /* not lint */
#include <sys/types.h>
#include <sys/file.h>
#include <err.h>
#include <locale.h>
#include <pwd.h>
#include <stdio.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include <utmp.h>
static void usage __P((void));
void output __P((struct utmp *));
int
main(argc, argv)
int argc;
char **argv;
{
register char *p;
struct utmp usr;
struct passwd *pw;
FILE *ufp, *file();
char *t;
(void) setlocale(LC_TIME, "");
switch (argc) {
case 1: /* who */
ufp = file(_PATH_UTMP);
/* 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 2: /* who utmp_file */
ufp = file(argv[1]);
/* all entries */
while (fread((char *)&usr, sizeof(usr), 1, ufp) == 1)
output(&usr);
break;
case 3: /* who am i */
if (strcmp(argv[1], "am")
|| (strcmp(argv[2], "I") && strcmp(argv[2], "i")))
usage();
ufp = file(_PATH_UTMP);
/* search through the utmp and find an entry for this tty */
if ((p = ttyname(0))) {
/* strip any directory component */
if ((t = rindex(p, '/')))
p = t + 1;
while (fread((char *)&usr, sizeof(usr), 1, ufp) == 1)
if (*usr.ut_name && !strcmp(usr.ut_line, p)) {
output(&usr);
exit(0);
}
/* 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);
break;
default:
usage();
}
exit(0);
}
static void
usage()
{
(void)fprintf(stderr, "%s\n%s\n",
"usage: who [file]",
" who am i");
exit(1);
}
void
output(up)
struct utmp *up;
{
char buf[80];
(void)printf("%-*.*s %-*.*s", UT_NAMESIZE, UT_NAMESIZE, up->ut_name,
UT_LINESIZE, UT_LINESIZE, up->ut_line);
(void)strftime(buf, sizeof(buf), "%c", localtime(&up->ut_time));
buf[sizeof(buf) - 1] = '\0';
(void)printf("%.12s", buf + 4);
if (*up->ut_host)
printf("\t(%.*s)", UT_HOSTSIZE, up->ut_host);
(void)putchar('\n');
}
FILE *
file(name)
char *name;
{
FILE *ufp;
if (!(ufp = fopen(name, "r")))
err(1, "%s", name);
return(ufp);
}