1 /* vi: set sw=4 ts=4: */
2 /*
3  * Mini who is used to display user name, login time,
4  * idle time and host name.
5  *
6  * Author: Da Chen  <dchen@ayrnetworks.com>
7  *
8  * This is a free document; you can redistribute it and/or
9  * modify it under the terms of the GNU General Public License
10  * as published by the Free Software Foundation:
11  *    http://www.gnu.org/copyleft/gpl.html
12  *
13  * Copyright (c) 2002 AYR Networks, Inc.
14  *
15  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
16  */
17 //config:config WHO
18 //config:	bool "who (3.9 kb)"
19 //config:	default y
20 //config:	depends on FEATURE_UTMP
21 //config:	help
22 //config:	Print users currently logged on.
23 //config:
24 // procps-ng has this variation of "who":
25 //config:config W
26 //config:	bool "w (3.8 kb)"
27 //config:	default y
28 //config:	depends on FEATURE_UTMP
29 //config:	help
30 //config:	Print users currently logged on.
31 //config:
32 //config:config USERS
33 //config:	bool "users (3.4 kb)"
34 //config:	default y
35 //config:	depends on FEATURE_UTMP
36 //config:	help
37 //config:	Print users currently logged on.
38 
39 //                APPLET_NOEXEC:name   main location        suid_type     help
40 //applet:IF_USERS(APPLET_NOEXEC(users, who, BB_DIR_USR_BIN, BB_SUID_DROP, users))
41 //applet:IF_W(    APPLET_NOEXEC(w,     who, BB_DIR_USR_BIN, BB_SUID_DROP, w))
42 //applet:IF_WHO(  APPLET_NOEXEC(who,   who, BB_DIR_USR_BIN, BB_SUID_DROP, who))
43 
44 //kbuild:lib-$(CONFIG_USERS) += who.o
45 //kbuild:lib-$(CONFIG_W)     += who.o
46 //kbuild:lib-$(CONFIG_WHO)   += who.o
47 
48 /* BB_AUDIT SUSv3 _NOT_ compliant -- missing options -b, -d, -l, -m, -p, -q, -r, -s, -t, -T, -u; Missing argument 'file'.  */
49 
50 //usage:#define users_trivial_usage
51 //usage:       ""
52 //usage:#define users_full_usage "\n\n"
53 //usage:       "Print the users currently logged on"
54 
55 //usage:#define w_trivial_usage
56 //usage:       ""
57 //usage:#define w_full_usage "\n\n"
58 //usage:       "Show who is logged on"
59 //
60 // procps-ng 3.3.10:
61 //           "\n	-h, --no-header"
62 //           "\n	-u, --no-current"
63 //	Ignores the username while figuring out the current process
64 //	and cpu times.  To demonstrate this, do a "su" and do a "w" and a "w -u".
65 //           "\n	-s, --short"
66 //	Short format.  Don't print the login time, JCPU or PCPU times.
67 //           "\n	-f, --from"
68 //	Toggle printing the from (remote hostname) field.
69 //	The default is for the from field to not be printed
70 //           "\n	-i, --ip-addr"
71 //	Display IP address instead of hostname for from field.
72 //           "\n	-o, --old-style"
73 //	Old style output. Prints blank space for idle times less than one minute.
74 // Example output:
75 //  17:28:00 up 4 days, 22:41,  4 users,  load average: 0.84, 0.97, 0.90
76 // USER     TTY        LOGIN@   IDLE   JCPU   PCPU WHAT
77 // root     tty1      Thu18    4days  4:33m  0.07s /bin/sh /etc/xdg/xfce4/xinitrc -- vt
78 // root     pts/1     Mon13    3:24m  1:01   0.01s w
79 
80 //usage:#define who_trivial_usage
81 //usage:       "[-aH]"
82 //usage:#define who_full_usage "\n\n"
83 //usage:       "Show who is logged on\n"
84 //usage:     "\n	-a	Show all"
85 //usage:     "\n	-H	Print column headers"
86 
87 #include "libbb.h"
88 
idle_string(char * str6,time_t t)89 static void idle_string(char *str6, time_t t)
90 {
91 	t = time(NULL) - t;
92 
93 	/*if (t < 60) {
94 		str6[0] = '.';
95 		str6[1] = '\0';
96 		return;
97 	}*/
98 	if (t >= 0 && t < (24 * 60 * 60)) {
99 		sprintf(str6, "%02d:%02d",
100 				(int) (t / (60 * 60)),
101 				(int) ((t % (60 * 60)) / 60));
102 		return;
103 	}
104 	strcpy(str6, "old");
105 }
106 
107 int who_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
who_main(int argc UNUSED_PARAM,char ** argv)108 int who_main(int argc UNUSED_PARAM, char **argv)
109 {
110 #define CNT_APPLET (ENABLE_USERS + ENABLE_W + ENABLE_WHO)
111 	int do_users = (ENABLE_USERS && (CNT_APPLET == 1 || applet_name[0] == 'u'));
112 	int do_w     = (ENABLE_W     && (CNT_APPLET == 1 || applet_name[1] == '\0'));
113 	int do_who   = (ENABLE_WHO   && (CNT_APPLET == 1 || applet_name[1] == 'h'));
114 	struct utmpx *ut;
115 	unsigned opt;
116 	const char *fmt = "%s";
117 
118 	opt = getopt32(argv, do_who ? "^" "aH" "\0" "=0": "^" "" "\0" "=0");
119 	if ((opt & 2) || do_w) /* -H or we are w */
120 		puts("USER\t\tTTY\t\tIDLE\tTIME\t\t HOST");
121 
122 	setutxent();
123 	while ((ut = getutxent()) != NULL) {
124 		if (ut->ut_user[0]
125 		 && ((opt & 1) || ut->ut_type == USER_PROCESS)
126 		) {
127 			if (!do_users) {
128 				char str6[6];
129 				char name[sizeof("/dev/") + sizeof(ut->ut_line) + 1];
130 				struct stat st;
131 				time_t seconds;
132 
133 				str6[0] = '?';
134 				str6[1] = '\0';
135 				strcpy(name, "/dev/");
136 				safe_strncpy(ut->ut_line[0] == '/' ? name : name + sizeof("/dev/")-1,
137 					ut->ut_line,
138 					sizeof(ut->ut_line)+1
139 				);
140 				if (stat(name, &st) == 0)
141 					idle_string(str6, st.st_atime);
142 				/* manpages say ut_tv.tv_sec *is* time_t,
143 				 * but some systems have it wrong */
144 				seconds = ut->ut_tv.tv_sec;
145 				/* How wide time field can be?
146 				 * "Nov 10 19:33:20": 15 chars
147 				 * "2010-11-10 19:33": 16 chars
148 				 */
149 				printf("%-15.*s %-15.*s %-7s %-16.16s %.*s\n",
150 						(int)sizeof(ut->ut_user), ut->ut_user,
151 						(int)sizeof(ut->ut_line), ut->ut_line,
152 						str6,
153 // TODO: with LANG=en_US.UTF-8, who from coreutils 8.25 shows
154 // TIME col as "2017-04-06 18:47" (the default format is "Apr  6 18:47").
155 // The former format looks saner to me. Switch to it unconditionally?
156 						ctime(&seconds) + 4,
157 						(int)sizeof(ut->ut_host), ut->ut_host
158 				);
159 			} else {
160 				printf(fmt, ut->ut_user);
161 				fmt = " %s";
162 			}
163 		}
164 	}
165 	if (do_users)
166 		bb_putchar('\n');
167 	if (ENABLE_FEATURE_CLEAN_UP)
168 		endutxent();
169 	return EXIT_SUCCESS;
170 }
171