busybox/coreutils/who.c
Denys Vlasenko 1a1203ff89 users,w,who,uptime,renice: make NOEXEC
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-08-07 16:47:34 +02:00

174 lines
5.4 KiB
C

/* vi: set sw=4 ts=4: */
/*----------------------------------------------------------------------
* Mini who is used to display user name, login time,
* idle time and host name.
*
* Author: Da Chen <dchen@ayrnetworks.com>
*
* This is a free document; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation:
* http://www.gnu.org/copyleft/gpl.html
*
* Copyright (c) 2002 AYR Networks, Inc.
*
* Licensed under GPLv2 or later, see file LICENSE in this source tree.
*
*----------------------------------------------------------------------
*/
//config:config WHO
//config: bool "who (3.7 kb)"
//config: default y
//config: depends on FEATURE_UTMP
//config: help
//config: Print users currently logged on.
//config:
// procps-ng has this variation of "who":
//config:config W
//config: bool "w (3.7 kb)"
//config: default y
//config: depends on FEATURE_UTMP
//config: help
//config: Print users currently logged on.
//config:
//config:config USERS
//config: bool "users (3.2 kb)"
//config: default y
//config: depends on FEATURE_UTMP
//config: help
//config: Print users currently logged on.
// APPLET_NOEXEC:name main location suid_type help
//applet:IF_USERS(APPLET_NOEXEC(users, who, BB_DIR_USR_BIN, BB_SUID_DROP, users))
//applet:IF_W( APPLET_NOEXEC(w, who, BB_DIR_USR_BIN, BB_SUID_DROP, w))
//applet:IF_WHO( APPLET_NOEXEC(who, who, BB_DIR_USR_BIN, BB_SUID_DROP, who))
//kbuild:lib-$(CONFIG_USERS) += who.o
//kbuild:lib-$(CONFIG_W) += who.o
//kbuild:lib-$(CONFIG_WHO) += who.o
/* BB_AUDIT SUSv3 _NOT_ compliant -- missing options -b, -d, -l, -m, -p, -q, -r, -s, -t, -T, -u; Missing argument 'file'. */
//usage:#define users_trivial_usage
//usage: ""
//usage:#define users_full_usage "\n\n"
//usage: "Print the users currently logged on"
//usage:#define w_trivial_usage
//usage: ""
//usage:#define w_full_usage "\n\n"
//usage: "Show who is logged on"
//
// procps-ng 3.3.10:
// "\n -h, --no-header"
// "\n -u, --no-current"
// Ignores the username while figuring out the current process
// and cpu times. To demonstrate this, do a "su" and do a "w" and a "w -u".
// "\n -s, --short"
// Short format. Don't print the login time, JCPU or PCPU times.
// "\n -f, --from"
// Toggle printing the from (remote hostname) field.
// The default is for the from field to not be printed
// "\n -i, --ip-addr"
// Display IP address instead of hostname for from field.
// "\n -o, --old-style"
// Old style output. Prints blank space for idle times less than one minute.
// Example output:
// 17:28:00 up 4 days, 22:41, 4 users, load average: 0.84, 0.97, 0.90
// USER TTY LOGIN@ IDLE JCPU PCPU WHAT
// root tty1 Thu18 4days 4:33m 0.07s /bin/sh /etc/xdg/xfce4/xinitrc -- vt
// root pts/1 Mon13 3:24m 1:01 0.01s w
//usage:#define who_trivial_usage
//usage: "[-a]"
//usage:#define who_full_usage "\n\n"
//usage: "Show who is logged on\n"
//usage: "\n -a Show all"
//usage: "\n -H Print column headers"
#include "libbb.h"
static void idle_string(char *str6, time_t t)
{
t = time(NULL) - t;
/*if (t < 60) {
str6[0] = '.';
str6[1] = '\0';
return;
}*/
if (t >= 0 && t < (24 * 60 * 60)) {
sprintf(str6, "%02d:%02d",
(int) (t / (60 * 60)),
(int) ((t % (60 * 60)) / 60));
return;
}
strcpy(str6, "old");
}
int who_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int who_main(int argc UNUSED_PARAM, char **argv)
{
#define CNT_APPLET (ENABLE_USERS + ENABLE_W + ENABLE_WHO)
int do_users = (ENABLE_USERS && (CNT_APPLET == 1 || applet_name[0] == 'u'));
int do_w = (ENABLE_W && (CNT_APPLET == 1 || applet_name[1] == '\0'));
int do_who = (ENABLE_WHO && (CNT_APPLET == 1 || applet_name[1] == 'h'));
struct utmpx *ut;
unsigned opt;
const char *fmt = "%s";
opt_complementary = "=0";
opt = getopt32(argv, do_who ? "aH" : "");
if ((opt & 2) || do_w) /* -H or we are w */
puts("USER\t\tTTY\t\tIDLE\tTIME\t\t HOST");
setutxent();
while ((ut = getutxent()) != NULL) {
if (ut->ut_user[0]
&& ((opt & 1) || ut->ut_type == USER_PROCESS)
) {
if (!do_users) {
char str6[6];
char name[sizeof("/dev/") + sizeof(ut->ut_line) + 1];
struct stat st;
time_t seconds;
str6[0] = '?';
str6[1] = '\0';
strcpy(name, "/dev/");
safe_strncpy(ut->ut_line[0] == '/' ? name : name + sizeof("/dev/")-1,
ut->ut_line,
sizeof(ut->ut_line)+1
);
if (stat(name, &st) == 0)
idle_string(str6, st.st_atime);
/* manpages say ut_tv.tv_sec *is* time_t,
* but some systems have it wrong */
seconds = ut->ut_tv.tv_sec;
/* How wide time field can be?
* "Nov 10 19:33:20": 15 chars
* "2010-11-10 19:33": 16 chars
*/
printf("%-15.*s %-15.*s %-7s %-16.16s %.*s\n",
(int)sizeof(ut->ut_user), ut->ut_user,
(int)sizeof(ut->ut_line), ut->ut_line,
str6,
// TODO: with LANG=en_US.UTF-8, who from coreutils 8.25 shows
// TIME col as "2017-04-06 18:47" (the default format is "Apr 6 18:47").
// The former format looks saner to me. Switch to it unconditionally?
ctime(&seconds) + 4,
(int)sizeof(ut->ut_host), ut->ut_host
);
} else {
printf(fmt, ut->ut_user);
fmt = " %s";
}
}
}
if (do_users)
bb_putchar('\n');
if (ENABLE_FEATURE_CLEAN_UP)
endutxent();
return EXIT_SUCCESS;
}