1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
|
/* GNU's users/who.
Copyright (C) 92, 93, 94, 95, 1996 Free Software Foundation, Inc.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
/* Written by jla; revised by djm */
/* Output format:
name [state] line time [idle] host
state: -T
name, line, time: not -q
idle: -u
Options:
-m Same as 'who am i', for POSIX.
-q Only user names and # logged on; overrides all other options.
-s Name, line, time (default).
-i, -u Idle hours and minutes; '.' means active in last minute;
'old' means idle for >24 hours.
-H Print column headings at top.
-w, -T -s plus mesg (+ or -, or ? if bad line). */
#include <config.h>
#include <stdio.h>
#include <sys/types.h>
#ifdef HAVE_UTMPX_H
#include <utmpx.h>
#define STRUCT_UTMP struct utmpx
#else
#include <utmp.h>
#define STRUCT_UTMP struct utmp
#endif
#include <time.h>
#include <getopt.h>
#ifdef HAVE_SYS_PARAM_H
#include <sys/param.h>
#endif
#include "system.h"
#include "version.h"
#include "error.h"
#if !defined (UTMP_FILE) && defined (_PATH_UTMP) /* 4.4BSD. */
#define UTMP_FILE _PATH_UTMP
#endif
#if defined (UTMPX_FILE) /* Solaris, SysVr4 */
#undef UTMP_FILE
#define UTMP_FILE UTMPX_FILE
#endif
#ifndef UTMP_FILE
#define UTMP_FILE "/etc/utmp"
#endif
#ifndef MAXHOSTNAMELEN
#define MAXHOSTNAMELEN 64
#endif
#ifndef S_IWGRP
#define S_IWGRP 020
#endif
#ifdef WHO
#define COMMAND_NAME "who"
#else
#ifdef USERS
#define COMMAND_NAME "users"
#else
error You must define one of WHO and USERS.
#endif /* USERS */
#endif /* WHO */
int gethostname ();
char *ttyname ();
char *xmalloc ();
/* The name this program was run with. */
char *program_name;
/* If nonzero, display usage information and exit. */
static int show_help;
/* If nonzero, print the version on standard output and exit. */
static int show_version;
#ifdef WHO
/* If nonzero, display only a list of usernames and count of
the users logged on.
Ignored for `who am i'. */
static int short_list;
/* If nonzero, display the hours:minutes since each user has touched
the keyboard, or "." if within the last minute, or "old" if
not within the last day. */
static int include_idle;
/* If nonzero, display a line at the top describing each field. */
static int include_heading;
/* If nonzero, display a `+' for each user if mesg y, a `-' if mesg n,
or a `?' if their tty cannot be statted. */
static int include_mesg;
#endif /* WHO */
static struct option const longopts[] =
{
#ifdef WHO
{"count", no_argument, NULL, 'q'},
{"idle", no_argument, NULL, 'u'},
{"heading", no_argument, NULL, 'H'},
{"message", no_argument, NULL, 'T'},
{"mesg", no_argument, NULL, 'T'},
{"writable", no_argument, NULL, 'T'},
#endif /* WHO */
{"help", no_argument, &show_help, 1},
{"version", no_argument, &show_version, 1},
{NULL, 0, NULL, 0}
};
static STRUCT_UTMP *utmp_contents;
#if defined (WHO) || defined (USERS)
/* Copy UT->ut_name into storage obtained from malloc. Then remove any
trailing spaces from the copy, NUL terminate it, and return the copy. */
static char *
extract_trimmed_name (const STRUCT_UTMP *ut)
{
char *p, *trimmed_name;
trimmed_name = xmalloc (sizeof (ut->ut_name) + 1);
strncpy (trimmed_name, ut->ut_name, sizeof (ut->ut_name));
/* Append a trailing space character. Some systems pad names shorter than
the maximum with spaces, others pad with NULs. Remove any spaces. */
trimmed_name[sizeof (ut->ut_name)] = ' ';
p = strchr (trimmed_name, ' ');
if (p != NULL)
*p = '\0';
return trimmed_name;
}
#endif /* WHO || USERS */
#if WHO
/* Return a string representing the time between WHEN and the time
that this function is first run. */
static const char *
idle_string (time_t when)
{
static time_t now = 0;
static char idle[10];
time_t seconds_idle;
if (now == 0)
time (&now);
seconds_idle = now - when;
if (seconds_idle < 60) /* One minute. */
return " . ";
if (seconds_idle < (24 * 60 * 60)) /* One day. */
{
sprintf (idle, "%02d:%02d",
(int) (seconds_idle / (60 * 60)),
(int) ((seconds_idle % (60 * 60)) / 60));
return (const char *) idle;
}
return _(" old ");
}
/* Display a line of information about entry THIS. */
static void
print_entry (STRUCT_UTMP *this)
{
struct stat stats;
time_t last_change;
char mesg;
#define DEV_DIR_WITH_TRAILING_SLASH "/dev/"
#define DEV_DIR_LEN (sizeof (DEV_DIR_WITH_TRAILING_SLASH) - 1)
char line[sizeof (this->ut_line) + DEV_DIR_LEN + 1];
/* Copy ut_line into LINE, prepending `/dev/' if ut_line is not
already an absolute pathname. Some system may put the full,
absolute pathname in ut_line. */
if (this->ut_line[0] == '/')
{
strncpy (line, this->ut_line, sizeof (this->ut_line));
line[sizeof (this->ut_line)] = '\0';
}
else
{
strcpy (line, DEV_DIR_WITH_TRAILING_SLASH);
strncpy (line + DEV_DIR_LEN, this->ut_line, sizeof (this->ut_line));
line[DEV_DIR_LEN + sizeof (this->ut_line)] = '\0';
}
if (stat (line, &stats) == 0)
{
mesg = (stats.st_mode & S_IWGRP) ? '+' : '-';
last_change = stats.st_atime;
}
else
{
mesg = '?';
last_change = 0;
}
printf ("%-8.*s", (int) sizeof (this->ut_name), this->ut_name);
if (include_mesg)
printf (" %c ", mesg);
printf (" %-8.*s", (int) sizeof (this->ut_line), this->ut_line);
#ifdef HAVE_UTMPX_H
printf (" %-12.12s", ctime (&this->ut_tv.tv_sec) + 4);
#else
printf (" %-12.12s", ctime (&this->ut_time) + 4);
#endif
if (include_idle)
{
if (last_change)
printf (" %s", idle_string (last_change));
else
printf (" . ");
}
#ifdef HAVE_UT_HOST
if (this->ut_host[0])
{
extern char *canon_host ();
char ut_host[sizeof (this->ut_host) + 1];
char *host = 0, *display = 0;
/* Copy the host name into UT_HOST, and ensure it's nul terminated. */
strncpy (ut_host, this->ut_host, (int) sizeof (this->ut_host));
ut_host[sizeof (this->ut_host)] = '\0';
/* Look for an X display. */
display = strrchr (ut_host, ':');
if (display)
*display++ = '\0';
if (*ut_host)
/* See if we can canonicalize it. */
host = canon_host (ut_host);
if (! host)
host = ut_host;
if (display)
printf (" (%s:%s)", host, display);
else
printf (" (%s)", host);
}
#endif
putchar ('\n');
}
/* Print the username of each valid entry and the number of valid entries
in `utmp_contents', which should have N elements. */
static void
list_entries_who (int n)
{
register STRUCT_UTMP *this = utmp_contents;
int entries;
entries = 0;
while (n--)
{
if (this->ut_name[0]
#ifdef USER_PROCESS
&& this->ut_type == USER_PROCESS
#endif
)
{
char *trimmed_name;
trimmed_name = extract_trimmed_name (this);
printf ("%s ", trimmed_name);
free (trimmed_name);
entries++;
}
this++;
}
printf (_("\n# users=%u\n"), entries);
}
#endif /* WHO */
#ifdef USERS
static int
userid_compare (const void *v_a, const void *v_b)
{
char **a = (char **) v_a;
char **b = (char **) v_b;
return strcmp (*a, *b);
}
static void
list_entries_users (int n)
{
register STRUCT_UTMP *this = utmp_contents;
char **u;
int i;
int n_entries;
n_entries = 0;
u = (char **) xmalloc (n * sizeof (u[0]));
for (i=0; i<n; i++)
{
if (this->ut_name[0]
#ifdef USER_PROCESS
&& this->ut_type == USER_PROCESS
#endif
)
{
char *trimmed_name;
trimmed_name = extract_trimmed_name (this);
u[n_entries] = trimmed_name;
++n_entries;
}
this++;
}
qsort (u, n_entries, sizeof (u[0]), userid_compare);
for (i=0; i<n_entries; i++)
{
int c;
fputs (u[i], stdout);
c = (i < n_entries-1 ? ' ' : '\n');
putchar (c);
}
for (i=0; i<n_entries; i++)
free (u[i]);
free (u);
}
#endif /* USERS */
#ifdef WHO
static void
print_heading (void)
{
printf ("%-8s ", "USER");
if (include_mesg)
printf (_("MESG "));
printf ("%-8s ", _("LINE"));
printf (_("LOGIN-TIME "));
if (include_idle)
printf (_("IDLE "));
printf (_("FROM\n"));
}
/* Display `utmp_contents', which should have N entries. */
static void
scan_entries (int n)
{
register STRUCT_UTMP *this = utmp_contents;
if (include_heading)
print_heading ();
while (n--)
{
if (this->ut_name[0]
#ifdef USER_PROCESS
&& this->ut_type == USER_PROCESS
#endif
)
print_entry (this);
this++;
}
}
#endif /* WHO */
/* Read the utmp file FILENAME into UTMP_CONTENTS and return the
number of entries it contains. */
static int
read_utmp (char *filename)
{
FILE *utmp;
struct stat file_stats;
int n_read;
size_t size;
utmp = fopen (filename, "r");
if (utmp == NULL)
error (1, errno, "%s", filename);
fstat (fileno (utmp), &file_stats);
size = file_stats.st_size;
if (size > 0)
utmp_contents = (STRUCT_UTMP *) xmalloc (size);
else
{
fclose (utmp);
return 0;
}
/* Use < instead of != in case the utmp just grew. */
n_read = fread (utmp_contents, 1, size, utmp);
if (ferror (utmp) || fclose (utmp) == EOF
|| n_read < size)
error (1, errno, "%s", filename);
return size / sizeof (STRUCT_UTMP);
}
/* Display a list of who is on the system, according to utmp file FILENAME. */
static void
who (char *filename)
{
int users;
users = read_utmp (filename);
#ifdef WHO
if (short_list)
list_entries_who (users);
else
scan_entries (users);
#else
#ifdef USERS
list_entries_users (users);
#endif /* USERS */
#endif /* WHO */
}
#ifdef WHO
/* Search `utmp_contents', which should have N entries, for
an entry with a `ut_line' field identical to LINE.
Return the first matching entry found, or NULL if there
is no matching entry. */
static STRUCT_UTMP *
search_entries (int n, char *line)
{
register STRUCT_UTMP *this = utmp_contents;
while (n--)
{
if (this->ut_name[0]
#ifdef USER_PROCESS
&& this->ut_type == USER_PROCESS
#endif
&& !strncmp (line, this->ut_line, sizeof (this->ut_line)))
return this;
this++;
}
return NULL;
}
/* Display the entry in utmp file FILENAME for this tty on standard input,
or nothing if there is no entry for it. */
static void
who_am_i (char *filename)
{
register STRUCT_UTMP *utmp_entry;
char hostname[MAXHOSTNAMELEN + 1];
char *tty;
if (gethostname (hostname, MAXHOSTNAMELEN + 1))
*hostname = 0;
if (include_heading)
{
printf ("%*s ", (int) strlen (hostname), " ");
print_heading ();
}
tty = ttyname (0);
if (tty == NULL)
return;
tty += 5; /* Remove "/dev/". */
utmp_entry = search_entries (read_utmp (filename), tty);
if (utmp_entry == NULL)
return;
printf ("%s!", hostname);
print_entry (utmp_entry);
}
static void
usage (int status)
{
if (status != 0)
fprintf (stderr, _("Try `%s --help' for more information.\n"),
program_name);
else
{
printf (_("Usage: %s [OPTION]... [ FILE | ARG1 ARG2 ]\n"), program_name);
printf (_("\
\n\
-H, --heading print line of column headings\n\
-T, -w, --mesg add user's message status as +, - or ?\n\
-i, -u, --idle add user idle time as HOURS:MINUTES, . or old\n\
-m only hostname and user associated with stdin\n\
-q, --count all login names and number of users logged on\n\
-s (ignored)\n\
--help display this help and exit\n\
--message same as -T\n\
--version output version information and exit\n\
--writeable same as -T\n\
\n\
If FILE not given, uses /etc/utmp. /etc/wtmp as FILE is common.\n\
If ARG1 ARG2 given, -m presumed: `am i' or `mom likes' are usual.\n\
"));
}
exit (status);
}
#endif /* WHO */
#ifdef USERS
static void
usage (int status)
{
if (status != 0)
fprintf (stderr, _("Try `%s --help' for more information.\n"),
program_name);
else
{
printf (_("Usage: %s [OPTION]... [ FILE ]\n"), program_name);
printf (_("\
Output who is currently logged in according to FILE.\n\
If FILE not given, uses /etc/utmp. /etc/wtmp as FILE is common.\n\
\n\
--help display this help and exit\n\
--version output version information and exit\n"));
}
exit (status);
}
#endif /* USERS */
void
main (int argc, char **argv)
{
int optc, longind;
#ifdef WHO
int my_line_only = 0;
#endif /* WHO */
program_name = argv[0];
#ifdef WHO
while ((optc = getopt_long (argc, argv, "imqsuwHT", longopts, &longind))
#else
while ((optc = getopt_long (argc, argv, "", longopts, &longind))
#endif /* WHO */
!= EOF)
{
switch (optc)
{
case 0:
break;
#ifdef WHO
case 'm':
my_line_only = 1;
break;
case 'q':
short_list = 1;
break;
case 's':
break;
case 'i':
case 'u':
include_idle = 1;
break;
case 'H':
include_heading = 1;
break;
case 'w':
case 'T':
include_mesg = 1;
break;
#endif /* WHO */
default:
usage (1);
}
}
if (show_version)
{
printf ("%s - %s\n", COMMAND_NAME, version_string);
exit (0);
}
if (show_help)
usage (0);
switch (argc - optind)
{
case 0: /* who */
#ifdef WHO
if (my_line_only)
who_am_i (UTMP_FILE);
else
#endif /* WHO */
who (UTMP_FILE);
break;
case 1: /* who <utmp file> */
#ifdef WHO
if (my_line_only)
who_am_i (argv[optind]);
else
#endif /* WHO */
who (argv[optind]);
break;
#ifdef WHO
case 2: /* who <blurf> <glop> */
who_am_i (UTMP_FILE);
break;
#endif /* WHO */
default: /* lose */
error (0, 0, _("too many arguments"));
usage (1);
}
exit (0);
}
|