Linux Audio

Check our new training course

Embedded Linux Audio

Check our new training course
with Creative Commons CC-BY-SA
lecture materials

Bootlin logo

Elixir Cross Referencer

Loading...
   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
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
/* vi: set sw=4 ts=4: */
/*
 * tiny-ls.c version 0.1.0: A minimalist 'ls'
 * Copyright (C) 1996 Brian Candler <B.Candler@pobox.com>
 *
 *  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 of the License, 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.
 */

/*
 * To achieve a small memory footprint, this version of 'ls' doesn't do any
 * file sorting, and only has the most essential command line switches
 * (i.e., the ones I couldn't live without :-) All features which involve
 * linking in substantial chunks of libc can be disabled.
 *
 * Although I don't really want to add new features to this program to
 * keep it small, I *am* interested to receive bug fixes and ways to make
 * it more portable.
 *
 * KNOWN BUGS:
 * 1. ls -l of a directory doesn't give "total <blocks>" header
 * 2. ls of a symlink to a directory doesn't list directory contents
 * 3. hidden files can make column width too large
 *
 * NON-OPTIMAL BEHAVIOUR:
 * 1. autowidth reads directories twice
 * 2. if you do a short directory listing without filetype characters
 *    appended, there's no need to stat each one
 * PORTABILITY:
 * 1. requires lstat (BSD) - how do you do it without?
 */

enum {
	TERMINAL_WIDTH = 80,	/* use 79 if terminal has linefold bug */
	COLUMN_GAP = 2,		/* includes the file type char */
};

/************************************************************************/

#include <sys/types.h>
#include <sys/stat.h>
#include <stdio.h>
#include <unistd.h>
#include <dirent.h>
#include <errno.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <fcntl.h>
#include <signal.h>
#include <termios.h>
#include <sys/ioctl.h>
#include "busybox.h"
#ifdef CONFIG_SELINUX
#include <fs_secure.h>
#include <flask_util.h>
#include <ss.h>
#endif

#ifdef CONFIG_FEATURE_LS_TIMESTAMPS
#include <time.h>
#endif

#ifndef MAJOR
#define MAJOR(dev) (((dev)>>8)&0xff)
#define MINOR(dev) ((dev)&0xff)
#endif

/* what is the overall style of the listing */
#define STYLE_AUTO      (0)
#define STYLE_COLUMNS   (1U<<21)	/* fill columns */
#define STYLE_LONG      (2U<<21)	/* one record per line, extended info */
#define STYLE_SINGLE    (3U<<21)	/* one record per line */

#define STYLE_MASK                 STYLE_SINGLE
#define STYLE_ONE_RECORD_FLAG      STYLE_LONG

/* 51306 lrwxrwxrwx  1 root     root         2 May 11 01:43 /bin/view -> vi* */
/* what file information will be listed */
#define LIST_INO		(1U<<0)
#define LIST_BLOCKS		(1U<<1)
#define LIST_MODEBITS	(1U<<2)
#define LIST_NLINKS		(1U<<3)
#define LIST_ID_NAME	(1U<<4)
#define LIST_ID_NUMERIC	(1U<<5)
#define LIST_CONTEXT	(1U<<6)
#define LIST_SIZE		(1U<<7)
#define LIST_DEV		(1U<<8)
#define LIST_DATE_TIME	(1U<<9)
#define LIST_FULLTIME	(1U<<10)
#define LIST_FILENAME	(1U<<11)
#define LIST_SYMLINK	(1U<<12)
#define LIST_FILETYPE	(1U<<13)
#define LIST_EXEC	(1U<<14)

#define LIST_MASK       ((LIST_EXEC << 1) - 1)

/* what files will be displayed */
/* TODO -- We may be able to make DISP_NORMAL 0 to save a bit slot. */
#define DISP_NORMAL		(1U<<14)	/* show normal filenames */
#define DISP_DIRNAME	(1U<<15)	/* 2 or more items? label directories */
#define DISP_HIDDEN		(1U<<16)	/* show filenames starting with .  */
#define DISP_DOT		(1U<<17)	/* show . and .. */
#define DISP_NOLIST		(1U<<18)	/* show directory as itself, not contents */
#define DISP_RECURSIVE	(1U<<19)	/* show directory and everything below it */
#define DISP_ROWS		(1U<<20)	/* print across rows */

#define DISP_MASK       (((DISP_ROWS << 1) - 1) & ~(DISP_NORMAL - 1))

#ifdef CONFIG_FEATURE_LS_SORTFILES
/* how will the files be sorted */
#define SORT_ORDER_FORWARD   0			/* sort in reverse order */
#define SORT_ORDER_REVERSE   (1U<<27)	/* sort in reverse order */

#define SORT_NAME      0			/* sort by file name */
#define SORT_SIZE      (1U<<28)		/* sort by file size */
#define SORT_ATIME     (2U<<28)		/* sort by last access time */
#define SORT_CTIME     (3U<<28)		/* sort by last change time */
#define SORT_MTIME     (4U<<28)		/* sort by last modification time */
#define SORT_VERSION   (5U<<28)		/* sort by version */
#define SORT_EXT       (6U<<28)		/* sort by file name extension */
#define SORT_DIR       (7U<<28)		/* sort by file or directory */

#define SORT_MASK      (7U<<28)
#endif

#ifdef CONFIG_FEATURE_LS_TIMESTAMPS
/* which of the three times will be used */
#define TIME_MOD       0
#define TIME_CHANGE    (1U<<23)
#define TIME_ACCESS    (1U<<24)

#define TIME_MASK      (3U<<23)
#endif

#ifdef CONFIG_FEATURE_LS_FOLLOWLINKS
#define FOLLOW_LINKS   (1U<<25)
#endif
#ifdef CONFIG_FEATURE_HUMAN_READABLE
#define LS_DISP_HR     (1U<<26)
#endif

#define LIST_SHORT	(LIST_FILENAME)
#define LIST_ISHORT	(LIST_INO | LIST_FILENAME)
#define LIST_LONG	(LIST_MODEBITS | LIST_NLINKS | LIST_ID_NAME | LIST_SIZE | \
						LIST_DATE_TIME | LIST_FILENAME | LIST_SYMLINK)
#define LIST_ILONG	(LIST_INO | LIST_LONG)

#define SPLIT_DIR      1
#define SPLIT_FILE     0
#define SPLIT_SUBDIR   2

#define TYPEINDEX(mode) (((mode) >> 12) & 0x0f)
#define TYPECHAR(mode)  ("0pcCd?bB-?l?s???" [TYPEINDEX(mode)])

#if defined(CONFIG_FEATURE_LS_FILETYPES) || defined(CONFIG_FEATURE_LS_COLOR)
# define APPCHAR(mode)   ("\0|\0\0/\0\0\0\0\0@\0=\0\0\0" [TYPEINDEX(mode)])
#endif

/* colored LS support by JaWi, janwillem.janssen@lxtreme.nl */
#ifdef CONFIG_FEATURE_LS_COLOR
static int show_color = 0;

#define COLOR(mode)	("\000\043\043\043\042\000\043\043"\
					"\000\000\044\000\043\000\000\040" [TYPEINDEX(mode)])
#define ATTR(mode)	("\00\00\01\00\01\00\01\00"\
					"\00\00\01\00\01\00\00\01" [TYPEINDEX(mode)])
#endif

/*
 * a directory entry and its stat info are stored here
 */
struct dnode {			/* the basic node */
	char *name;			/* the dir entry name */
	char *fullname;		/* the dir entry name */
	struct stat dstat;	/* the file stat info */
#ifdef CONFIG_SELINUX
	security_id_t sid;
#endif
	struct dnode *next;	/* point at the next node */
};
typedef struct dnode dnode_t;

static struct dnode **list_dir(const char *);
static struct dnode **dnalloc(int);
static int list_single(struct dnode *);

static unsigned int all_fmt;

#ifdef CONFIG_SELINUX
static int is_flask_enabled_flag;
#endif

#ifdef CONFIG_FEATURE_AUTOWIDTH
static int terminal_width = TERMINAL_WIDTH;
static unsigned short tabstops = COLUMN_GAP;
#else
#define tabstops COLUMN_GAP
#define terminal_width TERMINAL_WIDTH
#endif

static int status = EXIT_SUCCESS;

static struct dnode *my_stat(char *fullname, char *name)
{
	struct stat dstat;
	struct dnode *cur;
#ifdef CONFIG_SELINUX
	security_id_t sid;
#endif
	int rc;

#ifdef CONFIG_FEATURE_LS_FOLLOWLINKS
	if (all_fmt & FOLLOW_LINKS) {
#ifdef CONFIG_SELINUX
		if(is_flask_enabled_flag)
			rc = stat_secure(fullname, &dstat, &sid);
		else
#endif
			rc = stat(fullname, &dstat);
		if(rc)
		{
			bb_perror_msg("%s", fullname);
			status = EXIT_FAILURE;
			return 0;
		}
	} else
#endif
	{
#ifdef CONFIG_SELINUX
		if(is_flask_enabled_flag)
			rc = lstat_secure(fullname, &dstat, &sid);
		else
#endif
			rc = lstat(fullname, &dstat);
		if(rc)
		{
			bb_perror_msg("%s", fullname);
			status = EXIT_FAILURE;
			return 0;
		}
	}

	cur = (struct dnode *) xmalloc(sizeof(struct dnode));
	cur->fullname = fullname;
	cur->name = name;
	cur->dstat = dstat;
#ifdef CONFIG_SELINUX
	cur->sid = sid;
#endif
	return cur;
}

/*----------------------------------------------------------------------*/
#ifdef CONFIG_FEATURE_LS_COLOR
static char fgcolor(mode_t mode)
{
	/* Check wheter the file is existing (if so, color it red!) */
	if (errno == ENOENT) {
		return '\037';
	}
	if (LIST_EXEC && S_ISREG(mode)
		&& (mode & (S_IXUSR | S_IXGRP | S_IXOTH)))
		return COLOR(0xF000);	/* File is executable ... */
	return COLOR(mode);
}

/*----------------------------------------------------------------------*/
static char bgcolor(mode_t mode)
{
	if (LIST_EXEC && S_ISREG(mode)
		&& (mode & (S_IXUSR | S_IXGRP | S_IXOTH)))
		return ATTR(0xF000);	/* File is executable ... */
	return ATTR(mode);
}
#endif

/*----------------------------------------------------------------------*/
#if defined(CONFIG_FEATURE_LS_FILETYPES) || defined(CONFIG_FEATURE_LS_COLOR)
static char append_char(mode_t mode)
{
	if (!(all_fmt & LIST_FILETYPE))
		return '\0';
	if ((all_fmt & LIST_EXEC) && S_ISREG(mode)
		&& (mode & (S_IXUSR | S_IXGRP | S_IXOTH)))
		return '*';
	return APPCHAR(mode);
}
#endif

/*----------------------------------------------------------------------*/

#define countdirs(A,B) count_dirs((A), (B), 1)
#define countsubdirs(A,B) count_dirs((A), (B), 0)

static int count_dirs(struct dnode **dn, int nfiles, int notsubdirs)
{
	int i, dirs;

	if (dn == NULL || nfiles < 1)
		return (0);
	dirs = 0;
	for (i = 0; i < nfiles; i++) {
		if (S_ISDIR(dn[i]->dstat.st_mode)
			&& (notsubdirs
				|| ((dn[i]->name[0] != '.')
					|| (dn[i]->name[1] 
						&& ((dn[i]->name[1] != '.')
							|| dn[i]->name[2])))))
			dirs++;
	}
	return (dirs);
}

static int countfiles(struct dnode **dnp)
{
	int nfiles;
	struct dnode *cur;

	if (dnp == NULL)
		return (0);
	nfiles = 0;
	for (cur = dnp[0]; cur->next != NULL; cur = cur->next)
		nfiles++;
	nfiles++;
	return (nfiles);
}

/* get memory to hold an array of pointers */
static struct dnode **dnalloc(int num)
{
	struct dnode **p;

	if (num < 1)
		return (NULL);

	p = (struct dnode **) xcalloc((size_t) num,
								  (size_t) (sizeof(struct dnode *)));
	return (p);
}

#ifdef CONFIG_FEATURE_LS_RECURSIVE
static void dfree(struct dnode **dnp)
{
	struct dnode *cur, *next;

	if (dnp == NULL)
		return;

	cur = dnp[0];
	while (cur != NULL) {
		free(cur->fullname);	/* free the filename */
		next = cur->next;
		free(cur);		/* free the dnode */
		cur = next;
	}
	free(dnp);			/* free the array holding the dnode pointers */
}
#endif

static struct dnode **splitdnarray(struct dnode **dn, int nfiles, int which)
{
	int dncnt, i, d;
	struct dnode **dnp;

	if (dn == NULL || nfiles < 1)
		return (NULL);

	/* count how many dirs and regular files there are */
	if (which == SPLIT_SUBDIR)
		dncnt = countsubdirs(dn, nfiles);
	else {
		dncnt = countdirs(dn, nfiles);	/* assume we are looking for dirs */
		if (which == SPLIT_FILE)
			dncnt = nfiles - dncnt;	/* looking for files */
	}

	/* allocate a file array and a dir array */
	dnp = dnalloc(dncnt);

	/* copy the entrys into the file or dir array */
	for (d = i = 0; i < nfiles; i++) {
		if (S_ISDIR(dn[i]->dstat.st_mode)) {
			if (which & (SPLIT_DIR|SPLIT_SUBDIR)) {
				if ((which & SPLIT_DIR)
					|| ((dn[i]->name[0] != '.')
						|| (dn[i]->name[1]
							&& ((dn[i]->name[1] != '.')
								|| dn[i]->name[2])))) {
									dnp[d++] = dn[i];
								}
			}
		} else if (!(which & (SPLIT_DIR|SPLIT_SUBDIR))) {
			dnp[d++] = dn[i];
		}
	}
	return (dnp);
}

/*----------------------------------------------------------------------*/
#ifdef CONFIG_FEATURE_LS_SORTFILES
static int sortcmp(struct dnode *d1, struct dnode *d2)
{
	unsigned int sort_opts = all_fmt & SORT_MASK;
	int dif;

	dif = 0;			/* assume SORT_NAME */
	if (sort_opts == SORT_SIZE) {
		dif = (int) (d2->dstat.st_size - d1->dstat.st_size);
	} else if (sort_opts == SORT_ATIME) {
		dif = (int) (d2->dstat.st_atime - d1->dstat.st_atime);
	} else if (sort_opts == SORT_CTIME) {
		dif = (int) (d2->dstat.st_ctime - d1->dstat.st_ctime);
	} else if (sort_opts == SORT_MTIME) {
		dif = (int) (d2->dstat.st_mtime - d1->dstat.st_mtime);
	} else if (sort_opts == SORT_DIR) {
		dif = S_ISDIR(d2->dstat.st_mode) - S_ISDIR(d1->dstat.st_mode);
		/* } else if (sort_opts == SORT_VERSION) { */
		/* } else if (sort_opts == SORT_EXT) { */
	}

	if (dif == 0) {
		/* sort by name- may be a tie_breaker for time or size cmp */
#ifdef CONFIG_LOCALE_SUPPORT
		dif = strcoll(d1->name, d2->name);
#else
		dif = strcmp(d1->name, d2->name);
#endif
	}

	if (all_fmt & SORT_ORDER_REVERSE) {
		dif = -dif;
	}
	return (dif);
}

/*----------------------------------------------------------------------*/
static void shellsort(struct dnode **dn, int size)
{
	struct dnode *temp;
	int gap, i, j;

	/* shell short the array */
	if (dn == NULL || size < 2)
		return;

	for (gap = size / 2; gap > 0; gap /= 2) {
		for (i = gap; i < size; i++) {
			for (j = i - gap; j >= 0; j -= gap) {
				if (sortcmp(dn[j], dn[j + gap]) <= 0)
					break;
				/* they are out of order, swap them */
				temp = dn[j];
				dn[j] = dn[j + gap];
				dn[j + gap] = temp;
			}
		}
	}
}
#endif

/*----------------------------------------------------------------------*/
static void showfiles(struct dnode **dn, int nfiles)
{
	int i, ncols, nrows, row, nc;
	int column = 0;
	int nexttab = 0;
	int column_width = 0; /* for STYLE_LONG and STYLE_SINGLE not used */

	if (dn == NULL || nfiles < 1)
		return;

	if (all_fmt & STYLE_ONE_RECORD_FLAG) {
		ncols = 1;
	} else {
		/* find the longest file name-  use that as the column width */
		for (i = 0; i < nfiles; i++) {
			int len = strlen(dn[i]->name) +
#ifdef CONFIG_SELINUX
			((all_fmt & LIST_CONTEXT) ? 33 : 0) +
#endif
			((all_fmt & LIST_INO) ? 8 : 0) +
			((all_fmt & LIST_BLOCKS) ? 5 : 0);
			if (column_width < len)
				column_width = len;
		}
		column_width += tabstops;
		ncols = (int) (terminal_width / column_width);
	}

	if (ncols > 1) {
		nrows = nfiles / ncols;
		if ((nrows * ncols) < nfiles)
			nrows++;                /* round up fractionals */
	} else {
		nrows = nfiles;
		ncols = 1;
	}

	for (row = 0; row < nrows; row++) {
		for (nc = 0; nc < ncols; nc++) {
			/* reach into the array based on the column and row */
			i = (nc * nrows) + row;	/* assume display by column */
			if (all_fmt & DISP_ROWS)
				i = (row * ncols) + nc;	/* display across row */
			if (i < nfiles) {
				if (column > 0) {
					nexttab -= column;
					while (nexttab--) {
						putchar(' ');
						column++;
					}
			}
				nexttab = column + column_width;
				column += list_single(dn[i]);
		}
		}
		putchar('\n');
		column = 0;
	}
}

/*----------------------------------------------------------------------*/
static void showdirs(struct dnode **dn, int ndirs)
{
	int i, nfiles;
	struct dnode **subdnp;

#ifdef CONFIG_FEATURE_LS_RECURSIVE
	int dndirs;
	struct dnode **dnd;
#endif

	if (dn == NULL || ndirs < 1)
		return;

	for (i = 0; i < ndirs; i++) {
		if (all_fmt & (DISP_DIRNAME | DISP_RECURSIVE)) {
			printf("\n%s:\n", dn[i]->fullname);
		}
		subdnp = list_dir(dn[i]->fullname);
		nfiles = countfiles(subdnp);
		if (nfiles > 0) {
			/* list all files at this level */
#ifdef CONFIG_FEATURE_LS_SORTFILES
			shellsort(subdnp, nfiles);
#endif
			showfiles(subdnp, nfiles);
#ifdef CONFIG_FEATURE_LS_RECURSIVE
			if (all_fmt & DISP_RECURSIVE) {
				/* recursive- list the sub-dirs */
				dnd = splitdnarray(subdnp, nfiles, SPLIT_SUBDIR);
				dndirs = countsubdirs(subdnp, nfiles);
				if (dndirs > 0) {
#ifdef CONFIG_FEATURE_LS_SORTFILES
					shellsort(dnd, dndirs);
#endif
					showdirs(dnd, dndirs);
					free(dnd);	/* free the array of dnode pointers to the dirs */
				}
			}
			dfree(subdnp);	/* free the dnodes and the fullname mem */
#endif
		}
	}
}

/*----------------------------------------------------------------------*/
static struct dnode **list_dir(const char *path)
{
	struct dnode *dn, *cur, **dnp;
	struct dirent *entry;
	DIR *dir;
	int i, nfiles;

	if (path == NULL)
		return (NULL);

	dn = NULL;
	nfiles = 0;
	dir = opendir(path);
	if (dir == NULL) {
		bb_perror_msg("%s", path);
		status = EXIT_FAILURE;
		return (NULL);	/* could not open the dir */
	}
	while ((entry = readdir(dir)) != NULL) {
		char *fullname;

		/* are we going to list the file- it may be . or .. or a hidden file */
		if (entry->d_name[0] == '.') {
			if ((entry->d_name[1] == 0 || (
				entry->d_name[1] == '.'
				&& entry->d_name[2] == 0))
					&& !(all_fmt & DISP_DOT))
			continue;
			if (!(all_fmt & DISP_HIDDEN))
			continue;
		}
		fullname = concat_path_file(path, entry->d_name);
		cur = my_stat(fullname, strrchr(fullname, '/') + 1);
		if (!cur)
			continue;
		cur->next = dn;
		dn = cur;
		nfiles++;
	}
	closedir(dir);

	/* now that we know how many files there are
	   ** allocate memory for an array to hold dnode pointers
	 */
	if (dn == NULL)
		return (NULL);
	dnp = dnalloc(nfiles);
	for (i = 0, cur = dn; i < nfiles; i++) {
		dnp[i] = cur;	/* save pointer to node in array */
		cur = cur->next;
	}

	return (dnp);
}

/*----------------------------------------------------------------------*/
static int list_single(struct dnode *dn)
{
	int i, column = 0;

#ifdef CONFIG_FEATURE_LS_USERNAME
	char scratch[16];
#endif
#ifdef CONFIG_FEATURE_LS_TIMESTAMPS
	char *filetime;
	time_t ttime, age;
#endif
#if defined(CONFIG_FEATURE_LS_FILETYPES) || defined (CONFIG_FEATURE_LS_COLOR)
	struct stat info;
	char append;
#endif

	if (dn->fullname == NULL)
		return (0);

#ifdef CONFIG_FEATURE_LS_TIMESTAMPS
	ttime = dn->dstat.st_mtime;	/* the default time */
	if (all_fmt & TIME_ACCESS)
		ttime = dn->dstat.st_atime;
	if (all_fmt & TIME_CHANGE)
		ttime = dn->dstat.st_ctime;
	filetime = ctime(&ttime);
#endif
#ifdef CONFIG_FEATURE_LS_FILETYPES
	append = append_char(dn->dstat.st_mode);
#endif

	for (i = 0; i <= 31; i++) {
		switch (all_fmt & (1 << i)) {
		case LIST_INO:
			column += printf("%7ld ", (long int) dn->dstat.st_ino);
			break;
		case LIST_BLOCKS:
#if _FILE_OFFSET_BITS == 64
			column += printf("%4lld ", dn->dstat.st_blocks >> 1);
#else
			column += printf("%4ld ", dn->dstat.st_blocks >> 1);
#endif
			break;
		case LIST_MODEBITS:
			column += printf("%-10s ", (char *) bb_mode_string(dn->dstat.st_mode));
			break;
		case LIST_NLINKS:
			column += printf("%4ld ", (long) dn->dstat.st_nlink);
			break;
		case LIST_ID_NAME:
#ifdef CONFIG_FEATURE_LS_USERNAME
			my_getpwuid(scratch, dn->dstat.st_uid);
			printf("%-8.8s ", scratch);
			my_getgrgid(scratch, dn->dstat.st_gid);
			printf("%-8.8s", scratch);
			column += 17;
			break;
#endif
		case LIST_ID_NUMERIC:
			column += printf("%-8d %-8d", dn->dstat.st_uid, dn->dstat.st_gid);
			break;
		case LIST_SIZE:
		case LIST_DEV:
			if (S_ISBLK(dn->dstat.st_mode) || S_ISCHR(dn->dstat.st_mode)) {
				column += printf("%4d, %3d ", (int) MAJOR(dn->dstat.st_rdev),
					   (int) MINOR(dn->dstat.st_rdev));
			} else {
#ifdef CONFIG_FEATURE_HUMAN_READABLE
				if (all_fmt & LS_DISP_HR) {
					column += printf("%9s ",
							make_human_readable_str(dn->dstat.st_size, 1, 0));
				} else
#endif
				{
#if _FILE_OFFSET_BITS == 64
					column += printf("%9lld ", (long long) dn->dstat.st_size);
#else
					column += printf("%9ld ", dn->dstat.st_size);
#endif
				}
			}
			break;
#ifdef CONFIG_FEATURE_LS_TIMESTAMPS
		case LIST_FULLTIME:
			printf("%24.24s ", filetime);
			column += 25;
			break;
		case LIST_DATE_TIME:
			if ((all_fmt & LIST_FULLTIME) == 0) {
				age = time(NULL) - ttime;
				printf("%6.6s ", filetime + 4);
				if (age < 3600L * 24 * 365 / 2 && age > -15 * 60) {
					/* hh:mm if less than 6 months old */
					printf("%5.5s ", filetime + 11);
				} else {
					printf(" %4.4s ", filetime + 20);
				}
				column += 13;
			}
			break;
#endif
#ifdef CONFIG_SELINUX
		case LIST_CONTEXT:
			{
				char context[64];
				int len = sizeof(context);
				if(security_sid_to_context(dn->sid, context, &len))
				{
					strcpy(context, "unknown");
					len = 7;
				}
				printf("%-32s ", context);
				column += MAX(33, len);
			}
			break;
#endif
		case LIST_FILENAME:
#ifdef CONFIG_FEATURE_LS_COLOR
			errno = 0;
			if (show_color && !lstat(dn->fullname, &info)) {
				printf("\033[%d;%dm", bgcolor(info.st_mode),
					   fgcolor(info.st_mode));
			}
#endif
			column += printf("%s", dn->name);
#ifdef CONFIG_FEATURE_LS_COLOR
			if (show_color) {
				printf("\033[0m");
			}
#endif
			break;
		case LIST_SYMLINK:
			if (S_ISLNK(dn->dstat.st_mode)) {
				char *lpath = xreadlink(dn->fullname);

				if (lpath) {
					printf(" -> ");
#if defined(CONFIG_FEATURE_LS_FILETYPES) || defined (CONFIG_FEATURE_LS_COLOR)
					if (!stat(dn->fullname, &info)) {
						append = append_char(info.st_mode);
					}
#endif
#ifdef CONFIG_FEATURE_LS_COLOR
					if (show_color) {
						errno = 0;
						printf("\033[%d;%dm", bgcolor(info.st_mode),
							   fgcolor(info.st_mode));
					}
#endif
					column += printf("%s", lpath) + 4;
#ifdef CONFIG_FEATURE_LS_COLOR
					if (show_color) {
						printf("\033[0m");
					}
#endif
					free(lpath);
				}
			}
			break;
#ifdef CONFIG_FEATURE_LS_FILETYPES
		case LIST_FILETYPE:
			if (append != '\0') {
				printf("%1c", append);
				column++;
			}
			break;
#endif
		}
	}

	return column;
}

/*----------------------------------------------------------------------*/

/* "[-]Cadil1", POSIX mandated options, busybox always supports */
/* "[-]gnsx", POSIX non-mandated options, busybox always supports */
/* "[-]Ak" GNU options, busybox always supports */
/* "[-]FLRctur", POSIX mandated options, busybox optionally supports */
/* "[-]p", POSIX non-mandated options, busybox optionally supports */
/* "[-]SXvThw", GNU options, busybox optionally supports */
/* "[-]K", SELinux mandated options, busybox optionally supports */
/* "[-]e", I think we made this one up */

#ifdef CONFIG_FEATURE_LS_TIMESTAMPS
# define LS_STR_TIMESTAMPS	"cetu"
#else
# define LS_STR_TIMESTAMPS	""
#endif

#ifdef CONFIG_FEATURE_LS_SORTFILES
# define LS_STR_SORTFILES	"SXrv"
#else
# define LS_STR_SORTFILES	""
#endif

#ifdef CONFIG_FEATURE_LS_FILETYPES
# define LS_STR_FILETYPES	"Fp"
#else
# define LS_STR_FILETYPES	""
#endif

#ifdef CONFIG_FEATURE_LS_FOLLOWLINKS
# define LS_STR_FOLLOW_LINKS	"L"
#else
# define LS_STR_FOLLOW_LINKS	""
#endif

#ifdef CONFIG_FEATURE_LS_RECURSIVE
# define LS_STR_RECURSIVE	"R"
#else
# define LS_STR_RECURSIVE	""
#endif

#ifdef CONFIG_FEATURE_HUMAN_READABLE
# define LS_STR_HUMAN_READABLE	"h"
#else
# define LS_STR_HUMAN_READABLE	""
#endif

#ifdef CONFIG_SELINUX
# define LS_STR_SELINUX	"K"
#else
# define LS_STR_SELINUX	""
#endif

#ifdef CONFIG_FEATURE_AUTOWIDTH
# define LS_STR_AUTOWIDTH	"T:w:"
#else
# define LS_STR_AUTOWIDTH	""
#endif

static const char ls_options[]="Cadil1gnsxAk" \
	LS_STR_TIMESTAMPS \
	LS_STR_SORTFILES \
	LS_STR_FILETYPES \
	LS_STR_FOLLOW_LINKS \
	LS_STR_RECURSIVE \
	LS_STR_HUMAN_READABLE \
	LS_STR_SELINUX \
	LS_STR_AUTOWIDTH;

#define LIST_MASK_TRIGGER	LIST_SHORT
#define STYLE_MASK_TRIGGER	STYLE_MASK
#define SORT_MASK_TRIGGER	SORT_MASK
#define DISP_MASK_TRIGGER	DISP_ROWS
#define TIME_MASK_TRIGGER	TIME_MASK

static const unsigned opt_flags[] = {
	LIST_SHORT | STYLE_COLUMNS,	/* C */
	DISP_HIDDEN | DISP_DOT,    	/* a */
	DISP_NOLIST,               	/* d */
	LIST_INO,                  	/* i */
	LIST_LONG | STYLE_LONG,    	/* l - remember LS_DISP_HR in mask! */
	LIST_SHORT | STYLE_SINGLE, 	/* 1 */
	0,                         	/* g - ingored */
	LIST_ID_NUMERIC,           	/* n */
	LIST_BLOCKS,              	/* s */
	DISP_ROWS,                	/* x */
	DISP_HIDDEN,              	/* A */
#ifdef CONFIG_SELINUX
	LIST_CONTEXT,             	/* k */
#else
	0,                        	/* k - ingored */
#endif
#ifdef CONFIG_FEATURE_LS_TIMESTAMPS
# ifdef CONFIG_FEATURE_LS_SORTFILES
	TIME_CHANGE | SORT_CTIME,	/* c */
# else
	TIME_CHANGE,             	/* c */
# endif
	LIST_FULLTIME,           	/* e */
# ifdef CONFIG_FEATURE_LS_SORTFILES
	SORT_MTIME,              	/* t */
# else
	0,                      	/* t - ignored -- is this correct? */
# endif
# ifdef CONFIG_FEATURE_LS_SORTFILES
	TIME_ACCESS | SORT_ATIME,	/* u */
# else
	TIME_ACCESS,             	/* u */
# endif
#endif
#ifdef CONFIG_FEATURE_LS_SORTFILES
	SORT_ORDER_REVERSE,       	/* r */
	SORT_SIZE,               	/* S */
	SORT_VERSION,             	/* v */
	SORT_EXT,                	/* v */
#endif
#ifdef CONFIG_FEATURE_LS_FILETYPES
	LIST_FILETYPE | LIST_EXEC,	/* F */
	LIST_FILETYPE,            	/* p */
#endif
#ifdef CONFIG_FEATURE_LS_FOLLOWLINKS
	FOLLOW_LINKS,             	/* L */
#endif
#ifdef CONFIG_FEATURE_LS_RECURSIVE
	DISP_RECURSIVE,           	/* R */
#endif
#ifdef CONFIG_FEATURE_HUMAN_READABLE
	LS_DISP_HR,               	/* h */
#endif
#ifdef CONFIG_SELINUX
	LIST_MODEBITS|LIST_NLINKS|LIST_CONTEXT|LIST_SIZE|LIST_DATE_TIME, /* K */
#endif
	(1U<<31)
};


/*----------------------------------------------------------------------*/

extern int ls_main(int argc, char **argv)
{
	struct dnode **dnd;
	struct dnode **dnf;
	struct dnode **dnp;
	struct dnode *dn;
	struct dnode *cur;
	long opt;
	int nfiles = 0;
	int dnfiles;
	int dndirs;
	int oi;
	int ac;
	int i;
	char **av;
#ifdef CONFIG_FEATURE_AUTOWIDTH
	char *tabstops_str = NULL;
	char *terminal_width_str = NULL;
#endif

#ifdef CONFIG_SELINUX
	is_flask_enabled_flag = is_flask_enabled();
#endif

	all_fmt = LIST_SHORT | DISP_NORMAL | STYLE_AUTO
#ifdef CONFIG_FEATURE_LS_TIMESTAMPS
		| TIME_MOD
#endif
#ifdef CONFIG_FEATURE_LS_SORTFILES
		| SORT_NAME | SORT_ORDER_FORWARD
#endif
		;

#ifdef CONFIG_FEATURE_AUTOWIDTH
	/* Obtain the terminal width.  */
	get_terminal_width_height(0, &terminal_width, NULL);
	/* Go one less... */
	terminal_width--;
#endif

#ifdef CONFIG_FEATURE_LS_COLOR
	if (isatty(fileno(stdout)))
		show_color = 1;
#endif

	/* process options */
#ifdef CONFIG_FEATURE_AUTOWIDTH
	opt = bb_getopt_ulflags(argc, argv, ls_options, &tabstops_str, &terminal_width_str);
	if (tabstops_str) {
		tabstops = atoi(tabstops_str);
	}
	if (terminal_width_str) {
		terminal_width = atoi(terminal_width_str);
	}
#else
	opt = bb_getopt_ulflags(argc, argv, ls_options);
#endif
	for (i = 0; opt_flags[i] != (1U<<31); i++) {
		if (opt & (1 << i)) {
			unsigned int flags = opt_flags[i];
			if (flags & LIST_MASK_TRIGGER) {
				all_fmt &= ~LIST_MASK;
			}
			if (flags & STYLE_MASK_TRIGGER) {
				all_fmt &= ~STYLE_MASK;
			}
#ifdef CONFIG_FEATURE_LS_SORTFILES
			if (flags & SORT_MASK_TRIGGER) {
				all_fmt &= ~SORT_MASK;
			}
#endif
			if (flags & DISP_MASK_TRIGGER) {
				all_fmt &= ~DISP_MASK;
			}
#ifdef CONFIG_FEATURE_LS_TIMESTAMPS
			if (flags & TIME_MASK_TRIGGER) {
				all_fmt &= ~TIME_MASK;
			}
#endif
			if (flags & LIST_CONTEXT) {
				all_fmt |= STYLE_SINGLE;
			}
#ifdef CONFIG_FEATURE_HUMAN_READABLE
			if (opt == 'l') {
				all_fmt &= ~LS_DISP_HR;
			}
#endif
			all_fmt |= flags;
		}
	}

	/* sort out which command line options take precedence */
#ifdef CONFIG_FEATURE_LS_RECURSIVE
	if (all_fmt & DISP_NOLIST)
		all_fmt &= ~DISP_RECURSIVE;	/* no recurse if listing only dir */
#endif
#if defined (CONFIG_FEATURE_LS_TIMESTAMPS) && defined (CONFIG_FEATURE_LS_SORTFILES)
	if (all_fmt & TIME_CHANGE)
		all_fmt = (all_fmt & ~SORT_MASK) | SORT_CTIME;
	if (all_fmt & TIME_ACCESS)
		all_fmt = (all_fmt & ~SORT_MASK) | SORT_ATIME;
#endif
	if ((all_fmt & STYLE_MASK) != STYLE_LONG) /* only for long list */
		all_fmt &= ~(LIST_ID_NUMERIC|LIST_FULLTIME|LIST_ID_NAME|LIST_ID_NUMERIC);
#ifdef CONFIG_FEATURE_LS_USERNAME
	if ((all_fmt & STYLE_MASK) == STYLE_LONG && (all_fmt & LIST_ID_NUMERIC))
		all_fmt &= ~LIST_ID_NAME;	/* don't list names if numeric uid */
#endif
			
	/* choose a display format */
	if ((all_fmt & STYLE_MASK) == STYLE_AUTO)
#if STYLE_AUTO != 0
		all_fmt = (all_fmt & ~STYLE_MASK)
				| (isatty(fileno(stdout)) ? STYLE_COLUMNS : STYLE_SINGLE);
#else
		all_fmt |= (isatty(fileno(stdout)) ? STYLE_COLUMNS : STYLE_SINGLE);
#endif

	/*
	 * when there are no cmd line args we have to supply a default "." arg.
	 * we will create a second argv array, "av" that will hold either
	 * our created "." arg, or the real cmd line args.  The av array
	 * just holds the pointers- we don't move the date the pointers
	 * point to.
	 */
	ac = argc - optind;	/* how many cmd line args are left */
	if (ac < 1) {
		av = (char **) xcalloc((size_t) 1, (size_t) (sizeof(char *)));
		av[0] = bb_xstrdup(".");
		ac = 1;
	} else {
		av = (char **) xcalloc((size_t) ac, (size_t) (sizeof(char *)));
		for (oi = 0; oi < ac; oi++) {
			av[oi] = argv[optind++];	/* copy pointer to real cmd line arg */
		}
	}

	/* now, everything is in the av array */
	if (ac > 1)
		all_fmt |= DISP_DIRNAME;	/* 2 or more items? label directories */

	/* stuff the command line file names into an dnode array */
	dn = NULL;
	for (oi = 0; oi < ac; oi++) {
		char *fullname = bb_xstrdup(av[oi]);

		cur = my_stat(fullname, fullname);
		if (!cur)
			continue;
		cur->next = dn;
		dn = cur;
		nfiles++;
	}

	/* now that we know how many files there are
	   ** allocate memory for an array to hold dnode pointers
	 */
	dnp = dnalloc(nfiles);
	for (i = 0, cur = dn; i < nfiles; i++) {
		dnp[i] = cur;	/* save pointer to node in array */
		cur = cur->next;
	}


	if (all_fmt & DISP_NOLIST) {
#ifdef CONFIG_FEATURE_LS_SORTFILES
		shellsort(dnp, nfiles);
#endif
		if (nfiles > 0)
			showfiles(dnp, nfiles);
	} else {
		dnd = splitdnarray(dnp, nfiles, SPLIT_DIR);
		dnf = splitdnarray(dnp, nfiles, SPLIT_FILE);
		dndirs = countdirs(dnp, nfiles);
		dnfiles = nfiles - dndirs;
		if (dnfiles > 0) {
#ifdef CONFIG_FEATURE_LS_SORTFILES
			shellsort(dnf, dnfiles);
#endif
			showfiles(dnf, dnfiles);
		}
		if (dndirs > 0) {
#ifdef CONFIG_FEATURE_LS_SORTFILES
			shellsort(dnd, dndirs);
#endif
			showdirs(dnd, dndirs);
		}
	}
	return (status);
}