summaryrefslogtreecommitdiffstats
path: root/eval.c
blob: b095279e9726bc2188f9c47a7bae0a66850384a1 (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
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
/*********************************************************************
 * bfs                                                               *
 * Copyright (C) 2015-2017 Tavian Barnes <tavianator@tavianator.com> *
 *                                                                   *
 * This program is free software. It comes without any warranty, to  *
 * the extent permitted by applicable law. You can redistribute it   *
 * and/or modify it under the terms of the Do What The Fuck You Want *
 * To Public License, Version 2, as published by Sam Hocevar. See    *
 * the COPYING file or http://www.wtfpl.net/ for more details.       *
 *********************************************************************/

#include "bfs.h"
#include "bftw.h"
#include "color.h"
#include "dstring.h"
#include "mtab.h"
#include "util.h"
#include <assert.h>
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <fnmatch.h>
#include <grp.h>
#include <pwd.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/resource.h>
#include <sys/stat.h>
#include <time.h>
#include <unistd.h>

struct eval_state {
	/** Data about the current file. */
	struct BFTW *ftwbuf;
	/** The parsed command line. */
	const struct cmdline *cmdline;
	/** The bftw() callback return value. */
	enum bftw_action action;
	/** The eval_cmdline() return value. */
	int *ret;
	/** Whether to quit immediately. */
	bool *quit;
	/** A stat() buffer, if necessary. */
	struct stat statbuf;
};

/**
 * Check if an error should be ignored.
 */
static bool eval_should_ignore(const struct eval_state *state, int error) {
	return state->cmdline->ignore_races
		&& (error == ENOENT || errno == ENOTDIR)
		&& state->ftwbuf->depth > 0;
}

/**
 * Report an error that occurs during evaluation.
 */
static void eval_error(struct eval_state *state) {
	if (!eval_should_ignore(state, errno)) {
		cfprintf(state->cmdline->cerr, "%{er}'%s': %s%{rs}\n", state->ftwbuf->path, strerror(errno));
		*state->ret = EXIT_FAILURE;
	}
}

/**
 * Perform a stat() call if necessary.
 */
static const struct stat *fill_statbuf(struct eval_state *state) {
	struct BFTW *ftwbuf = state->ftwbuf;
	if (!ftwbuf->statbuf) {
		if (fstatat(ftwbuf->at_fd, ftwbuf->at_path, &state->statbuf, ftwbuf->at_flags) == 0) {
			ftwbuf->statbuf = &state->statbuf;
		} else {
			eval_error(state);
		}
	}
	return ftwbuf->statbuf;
}

/**
 * Get the difference (in seconds) between two struct timespecs.
 */
static time_t timespec_diff(const struct timespec *lhs, const struct timespec *rhs) {
	time_t ret = lhs->tv_sec - rhs->tv_sec;
	if (lhs->tv_nsec < rhs->tv_nsec) {
		--ret;
	}
	return ret;
}

/**
 * Perform a comparison.
 */
static bool do_cmp(const struct expr *expr, long long n) {
	switch (expr->cmp_flag) {
	case CMP_EXACT:
		return n == expr->idata;
	case CMP_LESS:
		return n < expr->idata;
	case CMP_GREATER:
		return n > expr->idata;
	}

	return false;
}

/**
 * -true test.
 */
bool eval_true(const struct expr *expr, struct eval_state *state) {
	return true;
}

/**
 * -false test.
 */
bool eval_false(const struct expr *expr, struct eval_state *state) {
	return false;
}

/**
 * -executable, -readable, -writable tests.
 */
bool eval_access(const struct expr *expr, struct eval_state *state) {
	struct BFTW *ftwbuf = state->ftwbuf;
	return faccessat(ftwbuf->at_fd, ftwbuf->at_path, expr->idata, AT_EACCESS) == 0;
}

/**
 * -[acm]{min,time} tests.
 */
bool eval_acmtime(const struct expr *expr, struct eval_state *state) {
	const struct stat *statbuf = fill_statbuf(state);
	if (!statbuf) {
		return false;
	}

	const struct timespec *time = NULL;
	switch (expr->time_field) {
	case ATIME:
		time = &statbuf->st_atim;
		break;
	case CTIME:
		time = &statbuf->st_ctim;
		break;
	case MTIME:
		time = &statbuf->st_mtim;
		break;
	}
	assert(time);

	time_t diff = timespec_diff(&expr->reftime, time);
	switch (expr->time_unit) {
	case MINUTES:
		diff /= 60;
		break;
	case DAYS:
		diff /= 60*60*24;
		break;
	}

	return do_cmp(expr, diff);
}

/**
 * -[ac]?newer tests.
 */
bool eval_acnewer(const struct expr *expr, struct eval_state *state) {
	const struct stat *statbuf = fill_statbuf(state);
	if (!statbuf) {
		return false;
	}

	const struct timespec *time = NULL;
	switch (expr->time_field) {
	case ATIME:
		time = &statbuf->st_atim;
		break;
	case CTIME:
		time = &statbuf->st_ctim;
		break;
	case MTIME:
		time = &statbuf->st_mtim;
		break;
	}
	assert(time);

	return time->tv_sec > expr->reftime.tv_sec
		|| (time->tv_sec == expr->reftime.tv_sec && time->tv_nsec > expr->reftime.tv_nsec);
}

/**
 * -used test.
 */
bool eval_used(const struct expr *expr, struct eval_state *state) {
	const struct stat *statbuf = fill_statbuf(state);
	if (!statbuf) {
		return false;
	}

	time_t diff = timespec_diff(&statbuf->st_atim, &statbuf->st_ctim);
	diff /= 60*60*24;
	return do_cmp(expr, diff);
}

/**
 * -gid test.
 */
bool eval_gid(const struct expr *expr, struct eval_state *state) {
	const struct stat *statbuf = fill_statbuf(state);
	if (!statbuf) {
		return false;
	}

	return do_cmp(expr, statbuf->st_gid);
}

/**
 * -uid test.
 */
bool eval_uid(const struct expr *expr, struct eval_state *state) {
	const struct stat *statbuf = fill_statbuf(state);
	if (!statbuf) {
		return false;
	}

	return do_cmp(expr, statbuf->st_uid);
}

/**
 * -nogroup test.
 */
bool eval_nogroup(const struct expr *expr, struct eval_state *state) {
	const struct stat *statbuf = fill_statbuf(state);
	if (!statbuf) {
		return false;
	}

	return getgrgid(statbuf->st_gid) == NULL;
}

/**
 * -nouser test.
 */
bool eval_nouser(const struct expr *expr, struct eval_state *state) {
	const struct stat *statbuf = fill_statbuf(state);
	if (!statbuf) {
		return false;
	}

	return getpwuid(statbuf->st_uid) == NULL;
}

/**
 * -delete action.
 */
bool eval_delete(const struct expr *expr, struct eval_state *state) {
	struct BFTW *ftwbuf = state->ftwbuf;

	// Don't try to delete the current directory
	if (strcmp(ftwbuf->path, ".") == 0) {
		return true;
	}

	int flag = 0;
	if (ftwbuf->typeflag == BFTW_DIR) {
		flag |= AT_REMOVEDIR;
	}

	if (unlinkat(ftwbuf->at_fd, ftwbuf->at_path, flag) != 0) {
		eval_error(state);
		return false;
	}

	return true;
}

/** Finish any pending -exec ... + operations. */
static int eval_exec_finish(const struct expr *expr) {
	int ret = 0;
	if (expr->execbuf && bfs_exec_finish(expr->execbuf) != 0) {
		ret = -1;
	}
	if (expr->lhs && eval_exec_finish(expr->lhs) != 0) {
		ret = -1;
	}
	if (expr->rhs && eval_exec_finish(expr->rhs) != 0) {
		ret = -1;
	}
	return ret;
}

/**
 * -exec[dir]/-ok[dir] actions.
 */
bool eval_exec(const struct expr *expr, struct eval_state *state) {
	bool ret = bfs_exec(expr->execbuf, state->ftwbuf) == 0;
	if (errno != 0) {
		eval_error(state);
	}
	return ret;
}

/**
 * -exit action.
 */
bool eval_exit(const struct expr *expr, struct eval_state *state) {
	state->action = BFTW_STOP;
	*state->ret = expr->idata;
	*state->quit = true;
	return true;
}

/**
 * -depth N test.
 */
bool eval_depth(const struct expr *expr, struct eval_state *state) {
	return do_cmp(expr, state->ftwbuf->depth);
}

/**
 * -empty test.
 */
bool eval_empty(const struct expr *expr, struct eval_state *state) {
	bool ret = false;
	struct BFTW *ftwbuf = state->ftwbuf;

	if (ftwbuf->typeflag == BFTW_DIR) {
		int flags = O_RDONLY | O_CLOEXEC;
#ifdef O_DIRECTORY
		flags |= O_DIRECTORY;
#endif
		int dfd = openat(ftwbuf->at_fd, ftwbuf->at_path, flags);
		if (dfd < 0) {
			eval_error(state);
			goto done;
		}

		DIR *dir = fdopendir(dfd);
		if (!dir) {
			eval_error(state);
			close(dfd);
			goto done;
		}

		ret = true;

		while (true) {
			struct dirent *de;
			if (xreaddir(dir, &de) != 0) {
				eval_error(state);
				goto done_dir;
			}
			if (!de) {
				break;
			}

			if (strcmp(de->d_name, ".") != 0 && strcmp(de->d_name, "..") != 0) {
				ret = false;
				break;
			}
		}

	done_dir:
		closedir(dir);
	} else {
		const struct stat *statbuf = fill_statbuf(state);
		if (statbuf) {
			ret = statbuf->st_size == 0;
		}
	}

done:
	return ret;
}

/**
 * -fstype test.
 */
bool eval_fstype(const struct expr *expr, struct eval_state *state) {
	const struct stat *statbuf = fill_statbuf(state);
	if (!statbuf) {
		return false;
	}

	const char *type = bfs_fstype(state->cmdline->mtab, statbuf);
	return strcmp(type, expr->sdata) == 0;
}

/**
 * -hidden test.
 */
bool eval_hidden(const struct expr *expr, struct eval_state *state) {
	struct BFTW *ftwbuf = state->ftwbuf;
	return ftwbuf->nameoff > 0 && ftwbuf->path[ftwbuf->nameoff] == '.';
}

/**
 * -nohidden action.
 */
bool eval_nohidden(const struct expr *expr, struct eval_state *state) {
	if (eval_hidden(expr, state)) {
		eval_prune(expr, state);
		return false;
	} else {
		return true;
	}
}

/**
 * -inum test.
 */
bool eval_inum(const struct expr *expr, struct eval_state *state) {
	const struct stat *statbuf = fill_statbuf(state);
	if (!statbuf) {
		return false;
	}

	return do_cmp(expr, statbuf->st_ino);
}

/**
 * -links test.
 */
bool eval_links(const struct expr *expr, struct eval_state *state) {
	const struct stat *statbuf = fill_statbuf(state);
	if (!statbuf) {
		return false;
	}

	return do_cmp(expr, statbuf->st_nlink);
}

/**
 * -i?lname test.
 */
bool eval_lname(const struct expr *expr, struct eval_state *state) {
	bool ret = false;
	char *name = NULL;

	struct BFTW *ftwbuf = state->ftwbuf;
	if (ftwbuf->typeflag != BFTW_LNK) {
		goto done;
	}

	const struct stat *statbuf = fill_statbuf(state);
	if (!statbuf) {
		goto done;
	}

	name = xreadlinkat(ftwbuf->at_fd, ftwbuf->at_path, statbuf->st_size);
	if (!name) {
		eval_error(state);
		goto done;
	}

	ret = fnmatch(expr->sdata, name, expr->idata) == 0;

done:
	free(name);
	return ret;
}

/**
 * -i?name test.
 */
bool eval_name(const struct expr *expr, struct eval_state *state) {
	struct BFTW *ftwbuf = state->ftwbuf;

	const char *name = ftwbuf->path + ftwbuf->nameoff;
	char *copy = NULL;
	if (ftwbuf->depth == 0) {
		// Any trailing slashes are not part of the name.  This can only
		// happen for the root path.
		const char *slash = strchr(name, '/');
		if (slash && slash > name) {
			copy = strndup(name, slash - name);
			if (!copy) {
				eval_error(state);
				return false;
			}
			name = copy;
		}
	}

	bool ret = fnmatch(expr->sdata, name, expr->idata) == 0;
	free(copy);
	return ret;
}

/**
 * -i?path test.
 */
bool eval_path(const struct expr *expr, struct eval_state *state) {
	struct BFTW *ftwbuf = state->ftwbuf;
	return fnmatch(expr->sdata, ftwbuf->path, expr->idata) == 0;
}

/**
 * -perm test.
 */
bool eval_perm(const struct expr *expr, struct eval_state *state) {
	const struct stat *statbuf = fill_statbuf(state);
	if (!statbuf) {
		return false;
	}

	mode_t mode = statbuf->st_mode;
	mode_t target;
	if (state->ftwbuf->typeflag == BFTW_DIR) {
		target = expr->dir_mode;
	} else {
		target = expr->file_mode;
	}

	switch (expr->mode_cmp) {
	case MODE_EXACT:
		return (mode & 07777) == target;

	case MODE_ALL:
		return (mode & target) == target;

	case MODE_ANY:
		return !(mode & target) == !target;
	}

	return false;
}

/**
 * -f?ls action.
 */
bool eval_fls(const struct expr *expr, struct eval_state *state) {
	CFILE *cfile = expr->cfile;
	FILE *file = cfile->file;
	const struct BFTW *ftwbuf = state->ftwbuf;
	const struct stat *statbuf = fill_statbuf(state);
	if (!statbuf) {
		goto done;
	}

	uintmax_t ino = statbuf->st_ino;
	uintmax_t blocks = (statbuf->st_blocks + 1)/2;
	char mode[11];
	format_mode(statbuf->st_mode, mode);
	uintmax_t nlink = statbuf->st_nlink;
	if (fprintf(file, "%9ju %6ju %s %3ju ", ino, blocks, mode, nlink) < 0) {
		goto error;
	}

	uintmax_t uid = statbuf->st_uid;
	struct passwd *pwd = getpwuid(uid);
	if (pwd) {
		if (fprintf(file, " %-8s", pwd->pw_name) < 0) {
			goto error;
		}
	} else {
		if (fprintf(file, " %-8ju", uid) < 0) {
			goto error;
		}
	}

	uintmax_t gid = statbuf->st_gid;
	struct group *grp = getgrgid(gid);
	if (grp) {
		if (fprintf(file, " %-8s", grp->gr_name) < 0) {
			goto error;
		}
	} else {
		if (fprintf(file, " %-8ju", gid) < 0) {
			goto error;
		}
	}

	uintmax_t size = statbuf->st_size;
	if (fprintf(file, " %8ju", size) < 0) {
		goto error;
	}

	time_t time = statbuf->st_mtim.tv_sec;
	time_t now = expr->reftime.tv_sec;
	time_t six_months_ago = now - 6*30*24*60*60;
	time_t tomorrow = now + 24*60*60;
	struct tm tm;
	if (xlocaltime(&time, &tm) != 0) {
		goto error;
	}
	char time_str[256];
	const char *time_format = "%b %e %H:%M";
	if (time <= six_months_ago || time >= tomorrow) {
		time_format = "%b %e  %Y";
	}
	if (!strftime(time_str, sizeof(time_str), time_format, &tm)) {
		errno = EOVERFLOW;
		goto error;
	}
	if (fprintf(file, " %s", time_str) < 0) {
		goto error;
	}

	if (cfprintf(cfile, " %P", ftwbuf) < 0) {
		goto error;
	}

	if (ftwbuf->typeflag == BFTW_LNK) {
		if (cfprintf(cfile, " -> %L", ftwbuf) < 0) {
			goto error;
		}
	}

	if (fputc('\n', file) == EOF) {
		goto error;
	}

done:
	return true;

error:
	eval_error(state);
	return true;
}

/**
 * -f?print action.
 */
bool eval_fprint(const struct expr *expr, struct eval_state *state) {
	CFILE *cfile = expr->cfile;
	if (cfile->colors) {
		fill_statbuf(state);
	}

	if (cfprintf(cfile, "%P\n", state->ftwbuf) < 0) {
		eval_error(state);
	}

	return true;
}

/**
 * -f?print0 action.
 */
bool eval_fprint0(const struct expr *expr, struct eval_state *state) {
	const char *path = state->ftwbuf->path;
	size_t length = strlen(path) + 1;
	if (fwrite(path, 1, length, expr->cfile->file) != length) {
		eval_error(state);
	}
	return true;
}

/**
 * -f?printf action.
 */
bool eval_fprintf(const struct expr *expr, struct eval_state *state) {
	if (expr->printf->needs_stat) {
		if (!fill_statbuf(state)) {
			goto done;
		}
	}

	if (bfs_printf(expr->cfile->file, expr->printf, state->ftwbuf) != 0) {
		eval_error(state);
	}

done:
	return true;
}

/**
 * -prune action.
 */
bool eval_prune(const struct expr *expr, struct eval_state *state) {
	state->action = BFTW_SKIP_SUBTREE;
	return true;
}

/**
 * -quit action.
 */
bool eval_quit(const struct expr *expr, struct eval_state *state) {
	state->action = BFTW_STOP;
	*state->quit = true;
	return true;
}

/**
 * -i?regex test.
 */
bool eval_regex(const struct expr *expr, struct eval_state *state) {
	const char *path = state->ftwbuf->path;
	size_t len = strlen(path);
	regmatch_t match = {
		.rm_so = 0,
		.rm_eo = len,
	};

	int flags = 0;
#ifdef REG_STARTEND
	flags |= REG_STARTEND;
#endif
	int err = regexec(expr->regex, path, 1, &match, flags);
	if (err == 0) {
		return match.rm_so == 0 && match.rm_eo == len;
	} else if (err != REG_NOMATCH) {
		char *str = xregerror(err, expr->regex);
		if (str) {
			cfprintf(state->cmdline->cerr, "%{er}'%s': %s%{rs}\n", path, str);
			free(str);
		} else {
			perror("xregerror()");
		}

		*state->ret = EXIT_FAILURE;
	}

	return false;
}

/**
 * -samefile test.
 */
bool eval_samefile(const struct expr *expr, struct eval_state *state) {
	const struct stat *statbuf = fill_statbuf(state);
	if (!statbuf) {
		return false;
	}

	return statbuf->st_dev == expr->dev && statbuf->st_ino == expr->ino;
}

/**
 * -size test.
 */
bool eval_size(const struct expr *expr, struct eval_state *state) {
	const struct stat *statbuf = fill_statbuf(state);
	if (!statbuf) {
		return false;
	}

	static off_t scales[] = {
		[SIZE_BLOCKS] = 512,
		[SIZE_BYTES] = 1,
		[SIZE_WORDS] = 2,
		[SIZE_KB] = 1024,
		[SIZE_MB] = 1024LL*1024,
		[SIZE_GB] = 1024LL*1024*1024,
		[SIZE_TB] = 1024LL*1024*1024*1024,
		[SIZE_PB] = 1024LL*1024*1024*1024*1024,
	};

	off_t scale = scales[expr->size_unit];
	off_t size = (statbuf->st_size + scale - 1)/scale; // Round up
	return do_cmp(expr, size);
}

/**
 * -sparse test.
 */
bool eval_sparse(const struct expr *expr, struct eval_state *state) {
	const struct stat *statbuf = fill_statbuf(state);
	if (!statbuf) {
		return false;
	}

	blkcnt_t expected = (statbuf->st_size + 511)/512;
	return statbuf->st_blocks < expected;
}

/**
 * -type test.
 */
bool eval_type(const struct expr *expr, struct eval_state *state) {
	return state->ftwbuf->typeflag & expr->idata;
}

/**
 * -xtype test.
 */
bool eval_xtype(const struct expr *expr, struct eval_state *state) {
	struct BFTW *ftwbuf = state->ftwbuf;

	int follow_flags = BFTW_LOGICAL;
	if (ftwbuf->depth == 0) {
		follow_flags |= BFTW_COMFOLLOW;
	}
	bool follow = state->cmdline->flags & follow_flags;

	bool is_link = ftwbuf->typeflag == BFTW_LNK;
	if (follow == is_link) {
		return eval_type(expr, state);
	}

	// -xtype does the opposite of everything else
	int at_flags = follow ? AT_SYMLINK_NOFOLLOW : 0;

	struct stat sb;
	if (fstatat(ftwbuf->at_fd, ftwbuf->at_path, &sb, at_flags) != 0) {
		if (!follow && (errno == ENOENT || errno == ENOTDIR)) {
			// Broken symlink
			return eval_type(expr, state);
		} else {
			eval_error(state);
			return false;
		}
	}

	return mode_to_typeflag(sb.st_mode) & expr->idata;
}

#if _POSIX_MONOTONIC_CLOCK > 0
#	define BFS_CLOCK CLOCK_MONOTONIC
#elif _POSIX_TIMERS > 0
#	define BFS_CLOCK CLOCK_REALTIME
#endif

/**
 * Call clock_gettime(), if available.
 */
static int eval_gettime(struct timespec *ts) {
#ifdef BFS_CLOCK
	int ret = clock_gettime(BFS_CLOCK, ts);
	if (ret != 0) {
		perror("clock_gettime()");
	}
	return ret;
#else
	return -1;
#endif
}

/**
 * Record the time that elapsed evaluating an expression.
 */
static void add_elapsed(struct expr *expr, const struct timespec *start, const struct timespec *end) {
	expr->elapsed.tv_sec += end->tv_sec - start->tv_sec;
	expr->elapsed.tv_nsec += end->tv_nsec - start->tv_nsec;
	if (expr->elapsed.tv_nsec < 0) {
		expr->elapsed.tv_nsec += 1000000000L;
		--expr->elapsed.tv_sec;
	} else if (expr->elapsed.tv_nsec >= 1000000000L) {
		expr->elapsed.tv_nsec -= 1000000000L;
		++expr->elapsed.tv_sec;
	}
}

/**
 * Evaluate an expression.
 */
static bool eval_expr(struct expr *expr, struct eval_state *state) {
	struct timespec start, end;
	bool time = state->cmdline->debug & DEBUG_RATES;
	if (time) {
		if (eval_gettime(&start) != 0) {
			time = false;
		}
	}

	bool ret = expr->eval(expr, state);

	if (time) {
		if (eval_gettime(&end) == 0) {
			add_elapsed(expr, &start, &end);
		}
	}

	++expr->evaluations;
	if (ret) {
		++expr->successes;
	}

	return ret;
}

/**
 * Evaluate a negation.
 */
bool eval_not(const struct expr *expr, struct eval_state *state) {
	return !eval_expr(expr->rhs, state);
}

/**
 * Evaluate a conjunction.
 */
bool eval_and(const struct expr *expr, struct eval_state *state) {
	if (!eval_expr(expr->lhs, state)) {
		return false;
	}

	if (*state->quit) {
		return false;
	}

	return eval_expr(expr->rhs, state);
}

/**
 * Evaluate a disjunction.
 */
bool eval_or(const struct expr *expr, struct eval_state *state) {
	if (eval_expr(expr->lhs, state)) {
		return true;
	}

	if (*state->quit) {
		return false;
	}

	return eval_expr(expr->rhs, state);
}

/**
 * Evaluate the comma operator.
 */
bool eval_comma(const struct expr *expr, struct eval_state *state) {
	eval_expr(expr->lhs, state);

	if (*state->quit) {
		return false;
	}

	return eval_expr(expr->rhs, state);
}

/**
 * Debug stat() calls.
 */
static void debug_stat(const struct eval_state *state) {
	struct BFTW *ftwbuf = state->ftwbuf;

	fprintf(stderr, "fstatat(");
	if (ftwbuf->at_fd == AT_FDCWD) {
		fprintf(stderr, "AT_FDCWD");
	} else {
		size_t baselen = strlen(ftwbuf->path) - strlen(ftwbuf->at_path);
		fprintf(stderr, "\"");
		fwrite(ftwbuf->path, 1, baselen, stderr);
		fprintf(stderr, "\"");
	}

	fprintf(stderr, ", \"%s\", ", ftwbuf->at_path);

	if (ftwbuf->at_flags == AT_SYMLINK_NOFOLLOW) {
		fprintf(stderr, "AT_SYMLINK_NOFOLLOW");
	} else {
		fprintf(stderr, "%d", ftwbuf->at_flags);
	}

	fprintf(stderr, ")\n");
}

/**
 * Type passed as the argument to the bftw() callback.
 */
struct callback_args {
	/** The parsed command line. */
	const struct cmdline *cmdline;
	/** Eventual return value from eval_cmdline(). */
	int ret;
	/** Whether to quit immediately. */
	bool quit;
};

/**
 * bftw() callback.
 */
static enum bftw_action cmdline_callback(struct BFTW *ftwbuf, void *ptr) {
	struct callback_args *args = ptr;

	const struct cmdline *cmdline = args->cmdline;

	struct eval_state state = {
		.ftwbuf = ftwbuf,
		.cmdline = cmdline,
		.action = BFTW_CONTINUE,
		.ret = &args->ret,
		.quit = &args->quit,
	};

	if (ftwbuf->typeflag == BFTW_ERROR) {
		if (!eval_should_ignore(&state, ftwbuf->error)) {
			args->ret = EXIT_FAILURE;
			cfprintf(cmdline->cerr, "%{er}'%s': %s%{rs}\n", ftwbuf->path, strerror(ftwbuf->error));
		}
		state.action = BFTW_SKIP_SUBTREE;
		goto done;
	}

	if (cmdline->xargs_safe && strpbrk(ftwbuf->path, " \t\n\'\"\\")) {
		args->ret = EXIT_FAILURE;
		cfprintf(cmdline->cerr, "%{er}'%s': Path is not safe for xargs.%{rs}\n", ftwbuf->path);
		state.action = BFTW_SKIP_SUBTREE;
		goto done;
	}

	if (ftwbuf->depth >= cmdline->maxdepth) {
		state.action = BFTW_SKIP_SUBTREE;
	}

	// In -depth mode, only handle directories on the BFTW_POST visit
	enum bftw_visit expected_visit = BFTW_PRE;
	if ((cmdline->flags & BFTW_DEPTH)
	    && ftwbuf->typeflag == BFTW_DIR
	    && ftwbuf->depth < cmdline->maxdepth) {
		expected_visit = BFTW_POST;
	}

	if (ftwbuf->visit == expected_visit
	    && ftwbuf->depth >= cmdline->mindepth
	    && ftwbuf->depth <= cmdline->maxdepth) {
		eval_expr(cmdline->expr, &state);
	}

done:
	if ((cmdline->debug & DEBUG_STAT) && ftwbuf->statbuf) {
		debug_stat(&state);
	}

	return state.action;
}

/**
 * Infer the number of open file descriptors we're allowed to have.
 */
static int infer_fdlimit(const struct cmdline *cmdline) {
	int ret = 4096;

	struct rlimit rl;
	if (getrlimit(RLIMIT_NOFILE, &rl) == 0) {
		if (rl.rlim_cur != RLIM_INFINITY) {
			ret = rl.rlim_cur;
		}
	}

	// 3 for std{in,out,err}
	int nopen = 3 + cmdline->nopen_files;

	// Check /dev/fd for the current number of open fds, if possible (we may
	// have inherited more than just the standard ones)
	DIR *dir = opendir("/dev/fd");
	if (dir) {
		// Account for 'dir' itself
		nopen = -1;

		while (true) {
			struct dirent *de;
			if (xreaddir(dir, &de) != 0 || !de) {
				break;
			}
			if (strcmp(de->d_name, ".") != 0 && strcmp(de->d_name, "..") != 0) {
				++nopen;
			}
		}

		closedir(dir);
	}

	// Extra fd needed by -empty
	int reserved = nopen + 1;

	if (ret > reserved) {
		ret -= reserved;
	} else {
		ret = 1;
	}

	return ret;
}

/**
 * Evaluate the command line.
 */
int eval_cmdline(const struct cmdline *cmdline) {
	if (!cmdline->expr) {
		return EXIT_SUCCESS;
	}

	if (cmdline->optlevel >= 4 && cmdline->expr->eval == eval_false) {
		if (cmdline->debug & DEBUG_OPT) {
			fputs("-O4: skipping evaluation of top-level -false\n", stderr);
		}
		return EXIT_SUCCESS;
	}

	int nopenfd = infer_fdlimit(cmdline);

	struct callback_args args = {
		.cmdline = cmdline,
		.ret = EXIT_SUCCESS,
		.quit = false,
	};

	for (struct root *root = cmdline->roots; root && !args.quit; root = root->next) {
		if (bftw(root->path, cmdline_callback, nopenfd, cmdline->flags, &args) != 0) {
			args.ret = EXIT_FAILURE;
			perror("bftw()");
		}
	}

	if (eval_exec_finish(cmdline->expr) != 0) {
		args.ret = EXIT_FAILURE;
	}

	if (cmdline->debug & DEBUG_RATES) {
		dump_cmdline(cmdline, true);
	}

	return args.ret;
}