summaryrefslogtreecommitdiff
path: root/usr.bin/at/at.c
blob: a8816599734af569a1db6a2b0d55f503f93ef592 (plain)
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
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
/*	$OpenBSD: at.c,v 1.40 2003/09/26 21:26:40 tedu Exp $	*/

/*
 *  at.c : Put file into atrun queue
 *  Copyright (C) 1993, 1994  Thomas Koenig
 *
 *  Atrun & Atq modifications
 *  Copyright (C) 1993  David Parsons
 *
 *  Traditional BSD behavior and other significant modifications
 *  Copyright (C) 2002-2003  Todd C. Miller
 *
 * 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. The name of the author(s) may not be used to endorse or promote
 *    products derived from this software without specific prior written
 *    permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``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 AUTHOR(S) 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, WETHER 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.
 */

#define	MAIN_PROGRAM

#include "cron.h"
#include "at.h"
#include "privs.h"
#include <limits.h>

#define ALARMC 10		/* Number of seconds to wait for timeout */
#define TIMESIZE 50		/* Size of buffer passed to strftime() */

#ifndef lint
static const char rcsid[] = "$OpenBSD: at.c,v 1.40 2003/09/26 21:26:40 tedu Exp $";
#endif

/* Variables to remove from the job's environment. */
char *no_export[] =
{
	"TERM", "TERMCAP", "DISPLAY", "_", "SHELLOPTS", "BASH_VERSINFO",
	"EUID", "GROUPS", "PPID", "UID", "SSH_AUTH_SOCK", "SSH_AGENT_PID",
};

int program = AT;		/* default program mode */
char atfile[MAX_FNAME];		/* path to the at spool file */
int fcreated;			/* whether or not we created the file yet */
char *atinput = NULL;		/* where to get input from */
char atqueue = 0;		/* which queue to examine for jobs (atq) */
char vflag = 0;			/* show completed but unremoved jobs (atq) */
char force = 0;			/* suppress errors (atrm) */
char interactive = 0;		/* interactive mode (atrm) */
static int send_mail = 0;	/* whether we are sending mail */

static void sigc(int);
static void alarmc(int);
static void writefile(const char *, time_t, char);
static void list_jobs(int, char **, int, int);
static time_t ttime(const char *);
static int check_permission(void);
static void panic(const char *);
static void perr(const char *);
static void perr2(const char *, const char *);
static void usage(void);
time_t parsetime(int, char **);

/*
 * Something fatal has happened, print error message and exit.
 */
static __dead void
panic(const char *a)
{
	(void)fprintf(stderr, "%s: %s\n", ProgramName, a);
	if (fcreated) {
		PRIV_START;
		unlink(atfile);
		PRIV_END;
	}

	exit(ERROR_EXIT);
}

/*
 * Two-parameter version of panic().
 */
static __dead void 
panic2(const char *a, const char *b)
{
	(void)fprintf(stderr, "%s: %s%s\n", ProgramName, a, b);
	if (fcreated) {
		PRIV_START;
		unlink(atfile);
		PRIV_END;
	}

	exit(ERROR_EXIT);
}

/*
 * Some operating system error; print error message and exit.
 */
static __dead void
perr(const char *a)
{
	if (!force)
		perror(a);
	if (fcreated) {
		PRIV_START;
		unlink(atfile);
		PRIV_END;
	}

	exit(ERROR_EXIT);
}

/*
 * Two-parameter version of perr().
 */
static __dead void 
perr2(const char *a, const char *b)
{
	if (!force)
		(void)fputs(a, stderr);
	perr(b);
}

static void 
sigc(int signo)
{
	/* If the user presses ^C, remove the spool file and exit. */
	if (fcreated) {
		PRIV_START;
		(void)unlink(atfile);
		PRIV_END;
	}

	_exit(ERROR_EXIT);
}

static void 
alarmc(int signo)
{
	/* just return */
}

static int
newjob(time_t runtimer, int queue)
{
	int fd, i;

	/*
	 * If we have a collision, try shifting the time by up to
	 * two minutes.  Perhaps it would be better to try different
	 * queues instead...
	 */
	for (i = 0; i < 120; i++) {
		snprintf(atfile, sizeof(atfile), "%s/%ld.%c", AT_DIR,
		    (long)runtimer, queue);
		fd = open(atfile, O_WRONLY | O_CREAT | O_EXCL, S_IRUSR);
		if (fd >= 0)
			return (fd);
		runtimer++;
	}
	return (-1);
}

/*
 * This does most of the work if at or batch are invoked for
 * writing a job.
 */
static void
writefile(const char *cwd, time_t runtimer, char queue)
{
	const char *ap;
	char *mailname, *shell;
	char timestr[TIMESIZE];
	struct passwd *pass_entry;
	struct tm runtime;
	int fdes, lockdes, fd2;
	FILE *fp, *fpin;
	struct sigaction act;
	char **atenv;
	int ch;
	mode_t cmask;
	extern char **environ;

	(void)setlocale(LC_TIME, "");

	/*
	 * Install the signal handler for SIGINT; terminate after removing the
	 * spool file if necessary
	 */
	bzero(&act, sizeof act);
	act.sa_handler = sigc;
	sigemptyset(&act.sa_mask);
	act.sa_flags = 0;
	sigaction(SIGINT, &act, NULL);

	PRIV_START;

	if ((lockdes = open(AT_DIR, O_RDONLY, 0)) < 0)
		perr("Cannot open jobs dir");

	/*
	 * Lock the jobs dir so we don't have to worry about someone
	 * else grabbing a file name out from under us.
	 * Set an alarm so we don't sleep forever waiting on the lock.
	 * If we don't succeed with ALARMC seconds, something is wrong...
	 */
	bzero(&act, sizeof act);
	act.sa_handler = alarmc;
	sigemptyset(&act.sa_mask);
#ifdef SA_INTERRUPT
	act.sa_flags = SA_INTERRUPT;
#endif
	sigaction(SIGALRM, &act, NULL);
	alarm(ALARMC);
	ch = flock(lockdes, LOCK_EX);
	alarm(0);
	if (ch != 0)
		panic("Unable to lock jobs dir");

	/*
	 * Create the file. The x bit is only going to be set after it has
	 * been completely written out, to make sure it is not executed in
	 * the meantime.  To make sure they do not get deleted, turn off
	 * their r bit.  Yes, this is a kluge.
	 */
	cmask = umask(S_IRUSR | S_IWUSR | S_IXUSR);
	if ((fdes = newjob(runtimer, queue)) == -1)
		perr("Cannot create atjob file");

	if ((fd2 = dup(fdes)) < 0)
		perr("Error in dup() of job file");

	if (fchown(fd2, real_uid, real_gid) != 0)
		perr("Cannot give away file");

	PRIV_END;

	/*
	 * We've successfully created the file; let's set the flag so it
	 * gets removed in case of an interrupt or error.
	 */
	fcreated = 1;

	/* Now we can release the lock, so other people can access it */
	(void)close(lockdes);

	if ((fp = fdopen(fdes, "w")) == NULL)
		panic("Cannot reopen atjob file");

	/*
	 * Get the userid to mail to, first by trying getlogin(), which asks
	 * the kernel, then from $LOGNAME or $USER, finally from getpwuid().
	 */
	mailname = getlogin();
	if (mailname == NULL && (mailname = getenv("LOGNAME")) == NULL)
		mailname = getenv("USER");

	if ((mailname == NULL) || (mailname[0] == '\0') ||
	    (strlen(mailname) > MAX_UNAME) || (getpwnam(mailname) == NULL)) {
		pass_entry = getpwuid(real_uid);
		if (pass_entry != NULL)
			mailname = pass_entry->pw_name;
	}

	/*
	 * Get the shell to run the job under.  First check $SHELL, falling
	 * back to the user's shell in the password database or, failing
	 * that, /bin/sh.
	 */
	if ((shell = getenv("SHELL")) == NULL || *shell == '\0') {
		pass_entry = getpwuid(real_uid);
		if (pass_entry != NULL && *pass_entry->pw_shell != '\0')
			shell = pass_entry->pw_shell;
		else
			shell = _PATH_BSHELL;
	}

	if (atinput != NULL) {
		fpin = freopen(atinput, "r", stdin);
		if (fpin == NULL)
			perr("Cannot open input file");
	}
	(void)fprintf(fp, "#!/bin/sh\n# atrun uid=%ld gid=%ld\n# mail %*s %d\n",
	    (long)real_uid, (long)real_gid, MAX_UNAME, mailname, send_mail);

	/* Write out the umask at the time of invocation */
	(void)fprintf(fp, "umask %o\n", cmask);

	/*
	 * Write out the environment. Anything that may look like a special
	 * character to the shell is quoted, except for \n, which is done
	 * with a pair of "'s.  Dont't export the no_export list (such as
	 * TERM or DISPLAY) because we don't want these.
	 */
	for (atenv = environ; *atenv != NULL; atenv++) {
		int export = 1;
		char *eqp;

		eqp = strchr(*atenv, '=');
		if (eqp == NULL)
			eqp = *atenv;
		else {
			int i;

			for (i = 0;i < sizeof(no_export) /
			    sizeof(no_export[0]); i++) {
				export = export
				    && (strncmp(*atenv, no_export[i],
					(size_t) (eqp - *atenv)) != 0);
			}
			eqp++;
		}

		if (export) {
			(void)fwrite(*atenv, sizeof(char), eqp - *atenv, fp);
			for (ap = eqp; *ap != '\0'; ap++) {
				if (*ap == '\n')
					(void)fprintf(fp, "\"\n\"");
				else {
					if (!isalnum(*ap)) {
						switch (*ap) {
						case '%': case '/': case '{':
						case '[': case ']': case '=':
						case '}': case '@': case '+':
						case '#': case ',': case '.':
						case ':': case '-': case '_':
							break;
						default:
							(void)fputc('\\', fp);
							break;
						}
					}
					(void)fputc(*ap, fp);
				}
			}
			(void)fputs("; export ", fp);
			(void)fwrite(*atenv, sizeof(char), eqp - *atenv - 1, fp);
			(void)fputc('\n', fp);
		}
	}
	/*
	 * Cd to the directory at the time and write out all the
	 * commands the user supplies from stdin.
	 */
	(void)fputs("cd ", fp);
	for (ap = cwd; *ap != '\0'; ap++) {
		if (*ap == '\n')
			fprintf(fp, "\"\n\"");
		else {
			if (*ap != '/' && !isalnum(*ap))
				(void)fputc('\\', fp);

			(void)fputc(*ap, fp);
		}
	}
	/*
	 * Test cd's exit status: die if the original directory has been
	 * removed, become unreadable or whatever.
	 */
	(void)fprintf(fp, " || {\n\t echo 'Execution directory inaccessible'"
	    " >&2\n\t exit 1\n}\n");

	if ((ch = getchar()) == EOF)
		panic("Input error");

	/* We want the job to run under the user's shell. */
	fprintf(fp, "%s << '_END_OF_AT_JOB'\n", shell);

	do {
		(void)fputc(ch, fp);
	} while ((ch = getchar()) != EOF);

	(void)fprintf(fp, "\n_END_OF_AT_JOB\n");
	if (ferror(fp))
		panic("Output error");

	if (ferror(stdin))
		panic("Input error");

	(void)fclose(fp);

	/*
	 * Set the x bit so that we're ready to start executing
	 */
	if (fchmod(fd2, S_IRUSR | S_IWUSR | S_IXUSR) < 0)
		perr("Cannot give away file");

	(void)close(fd2);

	/* Poke cron so it knows to reload the at spool. */
	PRIV_START;
	poke_daemon(AT_DIR, RELOAD_AT);
	PRIV_END;

	runtime = *localtime(&runtimer);
	strftime(timestr, TIMESIZE, "%a %b %e %T %Y", &runtime);
	(void)fprintf(stderr, "commands will be executed using %s\n", shell);
	(void)fprintf(stderr, "job %s at %s\n", &atfile[sizeof(AT_DIR)],
	    timestr);
}

/* Sort by creation time. */
static int
byctime(const void *v1, const void *v2)
{
	const struct atjob *j1 = *(struct atjob **)v1;
	const struct atjob *j2 = *(struct atjob **)v2;

	return (j1->ctime - j2->ctime);
}

/* Sort by job number (and thus execution time). */
static int
byjobno(const void *v1, const void *v2)
{
	const struct atjob *j1 = *(struct atjob **)v1;
	const struct atjob *j2 = *(struct atjob **)v2;

	if (j1->runtimer == j2->runtimer)
		return (j1->queue - j2->queue);
	return (j1->runtimer - j2->runtimer);
}

static void
print_job(struct atjob *job, int n, int shortformat)
{
	struct passwd *pw;
	struct tm runtime;
	char timestr[TIMESIZE];
	static char *ranks[] = {
		"th", "st", "nd", "rd", "th", "th", "th", "th", "th", "th"
	};

	runtime = *localtime(&job->runtimer);
	if (shortformat) {
		strftime(timestr, TIMESIZE, "%a %b %e %T %Y", &runtime);
		(void)printf("%ld.%c\t%s\n", (long)job->runtimer,
		    job->queue, timestr);
	} else {
		pw = getpwuid(job->uid);
		/* Rank hack shamelessly stolen from lpq */
		if (n / 10 == 1)
			printf("%3d%-5s", n,"th");
		else
			printf("%3d%-5s", n, ranks[n % 10]);
		strftime(timestr, TIMESIZE, "%b %e, %Y %R", &runtime);
		(void)printf("%-21.18s%-11.8s%10ld.%c   %c%s\n",
		    timestr, pw ? pw->pw_name : "???",
		    (long)job->runtimer, job->queue, job->queue,
		    (S_IXUSR & job->mode) ? "" : " (done)");
	}
}

/*
 * List all of a user's jobs in the queue, by looping through
 * AT_DIR, or all jobs if we are root.  If argc is > 0, argv
 * contains the list of users whose jobs shall be displayed. By
 * default, the list is sorted by execution date and queue.  If
 * csort is non-zero jobs will be sorted by creation/submission date.
 */
static void
list_jobs(int argc, char **argv, int count_only, int csort)
{
	struct passwd *pw;
	struct dirent *dirent;
	struct atjob **atjobs, **newatjobs, *job;
	struct stat stbuf;
	time_t runtimer;
	uid_t *uids;
	long l;
	char queue, *ep;
	DIR *spool;
	int i, shortformat, numjobs, maxjobs;

	if (argc) {
		if ((uids = malloc(sizeof(uid_t) * argc)) == NULL)
			panic("Insufficient virtual memory");

		for (i = 0; i < argc; i++) {
			if ((pw = getpwnam(argv[i])) == NULL)
				panic2(argv[i], ": invalid user name");
			if (pw->pw_uid != real_uid && real_uid != 0)
				panic("Only the superuser may display other users' jobs");
			uids[i] = pw->pw_uid;
		}
	} else
		uids = NULL;

	shortformat = strcmp(ProgramName, "at") == 0;

	PRIV_START;

	if (chdir(AT_DIR) != 0)
		perr2("Cannot change to ", AT_DIR);

	if ((spool = opendir(".")) == NULL)
		perr2("Cannot open ", AT_DIR);

	PRIV_END;

	if (fstat(spool->dd_fd, &stbuf) != 0)
		perr2("Cannot stat ", AT_DIR);

	/*
	 * The directory's link count should give us a good idea
	 * of how many files are in it.  Fudge things a little just
	 * in case someone adds a job or two.
	 */
	numjobs = 0;
	maxjobs = stbuf.st_nlink + 4;
	atjobs = (struct atjob **)malloc(maxjobs * sizeof(struct atjob *));
	if (atjobs == NULL)
		panic("Insufficient virtual memory");

	/* Loop over every file in the directory. */
	while ((dirent = readdir(spool)) != NULL) {
		PRIV_START;

		if (stat(dirent->d_name, &stbuf) != 0)
			perr2("Cannot stat in ", AT_DIR);

		PRIV_END;

		/*
		 * See it's a regular file and has its x bit turned on and
		 * is the user's
		 */
		if (!S_ISREG(stbuf.st_mode)
		    || ((stbuf.st_uid != real_uid) && !(real_uid == 0))
		    || !(S_IXUSR & stbuf.st_mode || vflag))
			continue;

		l = strtol(dirent->d_name, &ep, 10);
		if (*ep != '.' || !isalpha(*(ep + 1)) || *(ep + 2) != '\0' ||
		    l < 0 || l >= INT_MAX)
			continue;
		runtimer = (time_t)l;
		queue = *(ep + 1);

		if (atqueue && (queue != atqueue))
			continue;

		/* Check against specified user(s). */
		if (argc) {
			for (i = 0; i < argc; i++) {
				if (uids[0] == stbuf.st_uid)
					break;
			}
			if (i == argc)
				continue;	/* user doesn't match */
		}

		if (count_only) {
			numjobs++;
			continue;
		}

		job = (struct atjob *)malloc(sizeof(struct atjob));
		if (job == NULL)
			panic("Insufficient virtual memory");
		job->runtimer = runtimer;
		job->ctime = stbuf.st_ctime;
		job->uid = stbuf.st_uid;
		job->mode = stbuf.st_mode;
		job->queue = queue;
		if (numjobs == maxjobs) {
			int newjobs = maxjobs * 2;
			newatjobs = realloc(atjobs, newjobs * sizeof(job));
			if (newatjobs == NULL)
				panic("Insufficient virtual memory");
			atjobs = newatjobs;
			maxjobs = newjobs;
		}
		atjobs[numjobs++] = job;
	}
	free(uids);

	if (count_only || numjobs == 0) {
		if (numjobs == 0 && !shortformat)
			fprintf(stderr, "no files in queue.\n");
		else if (count_only)
			printf("%d\n", numjobs);
		free(atjobs);
		return;
	}

	/* Sort by job run time or by job creation time. */
	qsort(atjobs, numjobs, sizeof(struct atjob *),
	    csort ? byctime : byjobno);

	if (!shortformat)
		(void)puts(" Rank     Execution Date     Owner          "
		    "Job       Queue");

	for (i = 0; i < numjobs; i++) {
		print_job(atjobs[i], i + 1, shortformat);
		free(atjobs[i]);
	}
	free(atjobs);
}

static int
rmok(int job)
{
	int ch, junk;

	printf("%d: remove it? ", job);
	ch = getchar();
	while ((junk = getchar()) != EOF && junk != '\n')
		;
	return (ch == 'y' || ch == 'Y');
}

/*
 * Loop through all jobs in AT_DIR and display or delete ones
 * that match argv (may be job or username), or all if argc == 0.
 * Only the superuser may display/delete other people's jobs.
 */
static int
process_jobs(int argc, char **argv, int what)
{
	struct stat stbuf;
	struct dirent *dirent;
	struct passwd *pw;
	time_t runtimer;
	uid_t *uids;
	char **jobs, *ep, queue;
	long l;
	FILE *fp;
	DIR *spool;
	int job_matches, jobs_len, uids_len;
	int error, i, ch, changed;

	PRIV_START;

	if (chdir(AT_DIR) != 0)
		perr2("Cannot change to ", AT_DIR);

	if ((spool = opendir(".")) == NULL)
		perr2("Cannot open ", AT_DIR);

	PRIV_END;

	/* Convert argv into a list of jobs and uids. */
	jobs = NULL;
	uids = NULL;
	jobs_len = uids_len = 0;
	if (argc > 0) {
		if ((jobs = malloc(sizeof(char *) * argc)) == NULL ||
		    (uids = malloc(sizeof(uid_t) * argc)) == NULL)
			panic("Insufficient virtual memory");

		for (i = 0; i < argc; i++) {
			l = strtol(argv[i], &ep, 10);
			if (*ep == '.' && isalpha(*(ep + 1)) &&
			    *(ep + 2) == '\0' && l > 0 && l < INT_MAX)
				jobs[jobs_len++] = argv[i];
			else if ((pw = getpwnam(argv[i])) != NULL) {
				if (real_uid != pw->pw_uid && real_uid != 0) {
					fprintf(stderr, "%s: Only the superuser"
					    " may %s other users' jobs\n",
					    ProgramName, what == ATRM
					    ? "remove" : "view");
					exit(ERROR_EXIT);
				}
				uids[uids_len++] = pw->pw_uid;
			} else
				panic2(argv[i], ": invalid user name");
		}
	}

	/* Loop over every file in the directory */
	changed = 0;
	while ((dirent = readdir(spool)) != NULL) {

		PRIV_START;
		if (stat(dirent->d_name, &stbuf) != 0)
			perr2("Cannot stat in ", AT_DIR);
		PRIV_END;

		if (stbuf.st_uid != real_uid && real_uid != 0)
			continue;

		l = strtol(dirent->d_name, &ep, 10);
		if (*ep != '.' || !isalpha(*(ep + 1)) || *(ep + 2) != '\0' ||
		    l < 0 || l >= INT_MAX)
			continue;
		runtimer = (time_t)l;
		queue = *(ep + 1);

		/* Check runtimer against argv; argc==0 means do all. */
		job_matches = (argc == 0) ? 1 : 0;
		if (!job_matches) {
			for (i = 0; i < jobs_len; i++) {
				if (jobs[i] != NULL &&
				    strcmp(dirent->d_name, jobs[i]) == 0) {
					jobs[i] = NULL;
					job_matches = 1;
					break;
				}
			}
		}
		if (!job_matches) {
			for (i = 0; i < uids_len; i++) {
				if (uids[i] == stbuf.st_uid) {
					job_matches = 1;
					break;
				}
			}
		}

		if (job_matches) {
			switch (what) {
			case ATRM:
				PRIV_START;

				if (!interactive ||
				    (interactive && rmok(runtimer))) {
					if (unlink(dirent->d_name) == 0)
						changed = 1;
					else
						perr(dirent->d_name);
					if (!force && !interactive)
						fprintf(stderr,
						    "%s removed\n",
						    dirent->d_name);
				}

				PRIV_END;

				break;

			case CAT:
				PRIV_START;

				fp = fopen(dirent->d_name, "r");

				PRIV_END;

				if (!fp)
					perr("Cannot open file");

				while ((ch = getc(fp)) != EOF)
					putchar(ch);

				break;

			default:
				panic("Internal error");
				break;
			}
		}
	}
	for (error = 0, i = 0; i < jobs_len; i++) {
		if (jobs[i] != NULL) {
			if (!force)
				fprintf(stderr, "%s: %s: no such job\n",
				    ProgramName, jobs[i]);
			error++;
		}
	}
	free(jobs);
	free(uids);

	/* If we modied the spool, poke cron so it knows to reload. */
	if (changed) {
		PRIV_START;
		if (chdir(CRONDIR) != 0)
			perror(CRONDIR);
		else
			poke_daemon(AT_DIR, RELOAD_AT);
		PRIV_END;
	}

	return (error);
}

#define	ATOI2(s)	((s) += 2, ((s)[-2] - '0') * 10 + ((s)[-1] - '0'))

/*
 * This is pretty much a copy of stime_arg1() from touch.c.
 */
static time_t
ttime(const char *arg)
{
	struct timeval tv[2];
	time_t now;
	struct tm *t;
	int yearset;
	char *p;
	
	if (gettimeofday(&tv[0], NULL))
		panic("Cannot get current time");
	
	/* Start with the current time. */
	now = tv[0].tv_sec;
	if ((t = localtime(&now)) == NULL)
		panic("localtime");
	/* [[CC]YY]MMDDhhmm[.SS] */
	if ((p = strchr(arg, '.')) == NULL)
		t->tm_sec = 0;		/* Seconds defaults to 0. */
	else {
		if (strlen(p + 1) != 2)
			goto terr;
		*p++ = '\0';
		t->tm_sec = ATOI2(p);
	}
	
	yearset = 0;
	switch(strlen(arg)) {
	case 12:			/* CCYYMMDDhhmm */
		t->tm_year = ATOI2(arg);
		t->tm_year *= 100;
		yearset = 1;
		/* FALLTHROUGH */
	case 10:			/* YYMMDDhhmm */
		if (yearset) {
			yearset = ATOI2(arg);
			t->tm_year += yearset;
		} else {
			yearset = ATOI2(arg);
			t->tm_year = yearset + 2000;
		}
		t->tm_year -= 1900;	/* Convert to UNIX time. */
		/* FALLTHROUGH */
	case 8:				/* MMDDhhmm */
		t->tm_mon = ATOI2(arg);
		--t->tm_mon;		/* Convert from 01-12 to 00-11 */
		t->tm_mday = ATOI2(arg);
		t->tm_hour = ATOI2(arg);
		t->tm_min = ATOI2(arg);
		break;
	default:
		goto terr;
	}
	
	t->tm_isdst = -1;		/* Figure out DST. */
	tv[0].tv_sec = tv[1].tv_sec = mktime(t);
	if (tv[0].tv_sec != -1)
		return (tv[0].tv_sec);
	else
    terr:
		panic("out of range or illegal time specification: "
		    "[[CC]YY]MMDDhhmm[.SS]");
}

static int
check_permission(void)
{
	int ok;
	uid_t uid = geteuid();
	struct passwd *pw;

	if ((pw = getpwuid(uid)) == NULL) {
		perror("Cannot access password database");
		exit(ERROR_EXIT);
	}

	PRIV_START;

	ok = allowed(pw->pw_name, AT_ALLOW, AT_DENY);

	PRIV_END;

	return (ok);
}

static void
usage(void)
{
	/* Print usage and exit.  */
	switch (program) {
	case AT:
	case CAT:
		(void)fprintf(stderr,
		    "usage: at [-bm] [-f file] [-q queue] -t time_arg\n"
		    "       at [-bm] [-f file] [-q queue] timespec\n"
		    "       at -c job [job ...]\n"
		    "       at -l [-q queue] [job ...]\n"
		    "       at -r job [job ...]\n");
		break;
	case ATQ:
		(void)fprintf(stderr,
		    "usage: atq [-cnv] [-q queue] [name...]\n");
		break;
	case ATRM:
		(void)fprintf(stderr,
		    "usage: atrm [-afi] [[job] [name] ...]\n");
		break;
	case BATCH:
		(void)fprintf(stderr,
		    "usage: batch [-m] [-f file] [-q queue] [timespec]\n");
		break;
	}
	exit(ERROR_EXIT);
}

int
main(int argc, char **argv)
{
	time_t timer = -1;
	char queue = DEFAULT_AT_QUEUE;
	char queue_set = 0;
	char *options = "q:f:t:bcdlmrv";	/* default options for at */
	char cwd[PATH_MAX];
	int ch;
	int aflag = 0;
	int cflag = 0;
	int nflag = 0;

	if ((ProgramName = strrchr(argv[0], '/')) != NULL)
		ProgramName++;
	else
		ProgramName = argv[0];

	RELINQUISH_PRIVS;

	/* find out what this program is supposed to do */
	if (strcmp(ProgramName, "atq") == 0) {
		program = ATQ;
		options = "cnvq:";
	} else if (strcmp(ProgramName, "atrm") == 0) {
		program = ATRM;
		options = "afi";
	} else if (strcmp(ProgramName, "batch") == 0) {
		program = BATCH;
		options = "f:q:mv";
	}

	/* process whatever options we can process */
	while ((ch = getopt(argc, argv, options)) != -1) {
		switch (ch) {
		case 'a':
			aflag = 1;
			break;

		case 'i':
			interactive = 1;
			force = 0;
			break;

		case 'v':	/* show completed but unremoved jobs */
			/*
			 * This option is only useful when we are invoked
			 * as atq but we accept (and ignore) this flag in
			 * the other programs for backwards compatibility.
			 */
			vflag = 1;
			break;

		case 'm':	/* send mail when job is complete */
			send_mail = 1;
			break;

		case 'f':
			if (program == ATRM) {
				force = 1;
				interactive = 0;
			} else
				atinput = optarg;
			break;

		case 'q':	/* specify queue */
			if (strlen(optarg) > 1)
				usage();

			atqueue = queue = *optarg;
			if (!(islower(queue) || isupper(queue)))
				usage();

			queue_set = 1;
			break;

		case 'd':		/* for backwards compatibility */
		case 'r':
			program = ATRM;
			options = "";
			break;

		case 't':
			timer = ttime(optarg);
			break;

		case 'l':
			program = ATQ;
			options = "cnvq:";
			break;

		case 'b':
			program = BATCH;
			options = "f:q:mv";
			break;

		case 'c':
			if (program == ATQ) {
				cflag = 1;
			} else {
				program = CAT;
				options = "";
			}
			break;

		case 'n':
			nflag = 1;
			break;

		default:
			usage();
			break;
		}
	}
	argc -= optind;
	argv += optind;

	if (getcwd(cwd, sizeof(cwd)) == NULL)
		perr("Cannot get current working directory");

	set_cron_cwd();

	if (!check_permission())
		panic("You do not have permission to use at.");

	/* select our program */
	switch (program) {
	case ATQ:
		list_jobs(argc, argv, nflag, cflag);
		break;

	case ATRM:
	case CAT:
		if ((aflag && argc) || (!aflag && !argc))
			usage();
		exit(process_jobs(argc, argv, program));
		break;

	case AT:
		/* Time may have been specified via the -t flag. */
		if (timer == -1) {
			if (argc == 0)
				usage();
			else if ((timer = parsetime(argc, argv)) == -1)
				exit(ERROR_EXIT);
		}
		writefile(cwd, timer, queue);
		break;

	case BATCH:
		if (queue_set)
			queue = toupper(queue);
		else
			queue = DEFAULT_BATCH_QUEUE;

		if (argc == 0)
			timer = time(NULL);
		else if ((timer = parsetime(argc, argv)) == -1)
			exit(ERROR_EXIT);

		writefile(cwd, timer, queue);
		break;

	default:
		panic("Internal error");
		break;
	}
	exit(OK_EXIT);
}