summaryrefslogtreecommitdiff
path: root/src/cut.c
blob: 2a571483ad4eef0083c2472c0275061cd0c6fc62 (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
/* cut - remove parts of lines of files
   Copyright (C) 1997-2012 Free Software Foundation, Inc.
   Copyright (C) 1984 David M. Ihnat

   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 3 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, see <http://www.gnu.org/licenses/>.  */

/* Written by David Ihnat.  */

/* POSIX changes, bug fixes, long-named options, and cleanup
   by David MacKenzie <djm@gnu.ai.mit.edu>.

   Rewrite cut_fields and cut_bytes -- Jim Meyering.  */

#include <config.h>

#include <stdio.h>
#include <assert.h>
#include <getopt.h>
#include <sys/types.h>
#include "system.h"

#include "error.h"
#include "fadvise.h"
#include "getndelim2.h"
#include "hash.h"
#include "quote.h"
#include "xstrndup.h"

/* The official name of this program (e.g., no 'g' prefix).  */
#define PROGRAM_NAME "cut"

#define AUTHORS \
  proper_name ("David M. Ihnat"), \
  proper_name ("David MacKenzie"), \
  proper_name ("Jim Meyering")

#define FATAL_ERROR(Message)						\
  do									\
    {									\
      error (0, 0, (Message));						\
      usage (EXIT_FAILURE);						\
    }									\
  while (0)

/* Append LOW, HIGH to the list RP of range pairs, allocating additional
   space if necessary.  Update local variable N_RP.  When allocating,
   update global variable N_RP_ALLOCATED.  */

#define ADD_RANGE_PAIR(rp, low, high)			\
  do							\
    {							\
      if (low == 0 || high == 0)			\
        FATAL_ERROR (_("fields and positions are numbered from 1")); \
      if (n_rp >= n_rp_allocated)			\
        {						\
          (rp) = X2NREALLOC (rp, &n_rp_allocated);	\
        }						\
      rp[n_rp].lo = (low);				\
      rp[n_rp].hi = (high);				\
      ++n_rp;						\
    }							\
  while (0)

struct range_pair
  {
    size_t lo;
    size_t hi;
  };

/* This buffer is used to support the semantics of the -s option
   (or lack of same) when the specified field list includes (does
   not include) the first field.  In both of those cases, the entire
   first field must be read into this buffer to determine whether it
   is followed by a delimiter or a newline before any of it may be
   output.  Otherwise, cut_fields can do the job without using this
   buffer.  */
static char *field_1_buffer;

/* The number of bytes allocated for FIELD_1_BUFFER.  */
static size_t field_1_bufsize;

/* The largest field or byte index used as an endpoint of a closed
   or degenerate range specification;  this doesn't include the starting
   index of right-open-ended ranges.  For example, with either range spec
   '2-5,9-', '2-3,5,9-' this variable would be set to 5.  */
static size_t max_range_endpoint;

/* If nonzero, this is the index of the first field in a range that goes
   to end of line. */
static size_t eol_range_start;

/* This is a bit vector.
   In byte mode, which bytes to output.
   In field mode, which DELIM-separated fields to output.
   Both bytes and fields are numbered starting with 1,
   so the zeroth bit of this array is unused.
   A field or byte K has been selected if
   (K <= MAX_RANGE_ENDPOINT and is_printable_field(K))
    || (EOL_RANGE_START > 0 && K >= EOL_RANGE_START).  */
static unsigned char *printable_field;

enum operating_mode
  {
    undefined_mode,

    /* Output characters that are in the given bytes. */
    byte_mode,

    /* Output the given delimeter-separated fields. */
    field_mode
  };

static enum operating_mode operating_mode;

/* If true do not output lines containing no delimeter characters.
   Otherwise, all such lines are printed.  This option is valid only
   with field mode.  */
static bool suppress_non_delimited;

/* If nonzero, print all bytes, characters, or fields _except_
   those that were specified.  */
static bool complement;

/* The delimeter character for field mode. */
static unsigned char delim;

/* True if the --output-delimiter=STRING option was specified.  */
static bool output_delimiter_specified;

/* The length of output_delimiter_string.  */
static size_t output_delimiter_length;

/* The output field separator string.  Defaults to the 1-character
   string consisting of the input delimiter.  */
static char *output_delimiter_string;

/* True if we have ever read standard input. */
static bool have_read_stdin;

#define HT_RANGE_START_INDEX_INITIAL_CAPACITY 31

/* The set of range-start indices.  For example, given a range-spec list like
   '-b1,3-5,4-9,15-', the following indices will be recorded here: 1, 3, 15.
   Note that although '4' looks like a range-start index, it is in the middle
   of the '3-5' range, so it doesn't count.
   This table is created/used IFF output_delimiter_specified is set.  */
static Hash_table *range_start_ht;

/* For long options that have no equivalent short option, use a
   non-character as a pseudo short option, starting with CHAR_MAX + 1.  */
enum
{
  OUTPUT_DELIMITER_OPTION = CHAR_MAX + 1,
  COMPLEMENT_OPTION
};

static struct option const longopts[] =
{
  {"bytes", required_argument, NULL, 'b'},
  {"characters", required_argument, NULL, 'c'},
  {"fields", required_argument, NULL, 'f'},
  {"delimiter", required_argument, NULL, 'd'},
  {"only-delimited", no_argument, NULL, 's'},
  {"output-delimiter", required_argument, NULL, OUTPUT_DELIMITER_OPTION},
  {"complement", no_argument, NULL, COMPLEMENT_OPTION},
  {GETOPT_HELP_OPTION_DECL},
  {GETOPT_VERSION_OPTION_DECL},
  {NULL, 0, NULL, 0}
};

void
usage (int status)
{
  if (status != EXIT_SUCCESS)
    emit_try_help ();
  else
    {
      printf (_("\
Usage: %s OPTION... [FILE]...\n\
"),
              program_name);
      fputs (_("\
Print selected parts of lines from each FILE to standard output.\n\
\n\
"), stdout);
      fputs (_("\
Mandatory arguments to long options are mandatory for short options too.\n\
"), stdout);
      fputs (_("\
  -b, --bytes=LIST        select only these bytes\n\
  -c, --characters=LIST   select only these characters\n\
  -d, --delimiter=DELIM   use DELIM instead of TAB for field delimiter\n\
"), stdout);
      fputs (_("\
  -f, --fields=LIST       select only these fields;  also print any line\n\
                            that contains no delimiter character, unless\n\
                            the -s option is specified\n\
  -n                      (ignored)\n\
"), stdout);
      fputs (_("\
      --complement        complement the set of selected bytes, characters\n\
                            or fields\n\
"), stdout);
      fputs (_("\
  -s, --only-delimited    do not print lines not containing delimiters\n\
      --output-delimiter=STRING  use STRING as the output delimiter\n\
                            the default is to use the input delimiter\n\
"), stdout);
      fputs (HELP_OPTION_DESCRIPTION, stdout);
      fputs (VERSION_OPTION_DESCRIPTION, stdout);
      fputs (_("\
\n\
Use one, and only one of -b, -c or -f.  Each LIST is made up of one\n\
range, or many ranges separated by commas.  Selected input is written\n\
in the same order that it is read, and is written exactly once.\n\
"), stdout);
      fputs (_("\
Each range is one of:\n\
\n\
  N     N'th byte, character or field, counted from 1\n\
  N-    from N'th byte, character or field, to end of line\n\
  N-M   from N'th to M'th (included) byte, character or field\n\
  -M    from first to M'th (included) byte, character or field\n\
\n\
With no FILE, or when FILE is -, read standard input.\n\
"), stdout);
      emit_ancillary_info ();
    }
  exit (status);
}

static inline void
mark_range_start (size_t i)
{
  /* Record the fact that 'i' is a range-start index.  */
  void *ent_from_table = hash_insert (range_start_ht, (void*) i);
  if (ent_from_table == NULL)
    {
      /* Insertion failed due to lack of memory.  */
      xalloc_die ();
    }
  assert ((size_t) ent_from_table == i);
}

static inline void
mark_printable_field (size_t i)
{
  size_t n = i / CHAR_BIT;
  printable_field[n] |= (1 << (i % CHAR_BIT));
}

static inline bool
is_printable_field (size_t i)
{
  size_t n = i / CHAR_BIT;
  return (printable_field[n] >> (i % CHAR_BIT)) & 1;
}

static size_t
hash_int (const void *x, size_t tablesize)
{
#ifdef UINTPTR_MAX
  uintptr_t y = (uintptr_t) x;
#else
  size_t y = (size_t) x;
#endif
  return y % tablesize;
}

static bool
hash_compare_ints (void const *x, void const *y)
{
  return (x == y) ? true : false;
}

static bool
is_range_start_index (size_t i)
{
  return hash_lookup (range_start_ht, (void *) i) ? true : false;
}

/* Return nonzero if the K'th field or byte is printable.
   When returning nonzero, if RANGE_START is non-NULL,
   set *RANGE_START to true if K is the beginning of a range, and to
   false otherwise.  */

static bool
print_kth (size_t k, bool *range_start)
{
  bool k_selected
    = ((0 < eol_range_start && eol_range_start <= k)
       || (k <= max_range_endpoint && is_printable_field (k)));

  bool is_selected = k_selected ^ complement;
  if (range_start && is_selected)
    *range_start = is_range_start_index (k);

  return is_selected;
}

/* Comparison function for qsort to order the list of
   struct range_pairs.  */
static int
compare_ranges (const void *a, const void *b)
{
  int a_start = ((const struct range_pair *) a)->lo;
  int b_start = ((const struct range_pair *) b)->lo;
  return a_start < b_start ? -1 : a_start > b_start;
}

/* Given the list of field or byte range specifications FIELDSTR, set
   MAX_RANGE_ENDPOINT and allocate and initialize the PRINTABLE_FIELD
   array.  If there is a right-open-ended range, set EOL_RANGE_START
   to its starting index.  FIELDSTR should be composed of one or more
   numbers or ranges of numbers, separated by blanks or commas.
   Incomplete ranges may be given: '-m' means '1-m'; 'n-' means 'n'
   through end of line.  Return true if FIELDSTR contains at least
   one field specification, false otherwise.  */

/* FIXME-someday:  What if the user wants to cut out the 1,000,000-th
   field of some huge input file?  This function shouldn't have to
   allocate a table of a million bits just so we can test every
   field < 10^6 with an array dereference.  Instead, consider using
   an adaptive approach: if the range of selected fields is too large,
   but only a few fields/byte-offsets are actually selected, use a
   hash table.  If the range of selected fields is too large, and
   too many are selected, then resort to using the range-pairs (the
   'rp' array) directly.  */

static bool
set_fields (const char *fieldstr)
{
  size_t initial = 1;		/* Value of first number in a range.  */
  size_t value = 0;		/* If nonzero, a number being accumulated.  */
  bool lhs_specified = false;
  bool rhs_specified = false;
  bool dash_found = false;	/* True if a '-' is found in this field.  */
  bool field_found = false;	/* True if at least one field spec
                                   has been processed.  */

  struct range_pair *rp = NULL;
  size_t n_rp = 0;
  size_t n_rp_allocated = 0;
  size_t i;
  bool in_digits = false;

  /* Collect and store in RP the range end points.
     It also sets EOL_RANGE_START if appropriate.  */

  while (true)
    {
      if (*fieldstr == '-')
        {
          in_digits = false;
          /* Starting a range. */
          if (dash_found)
            FATAL_ERROR (_("invalid byte or field list"));
          dash_found = true;
          fieldstr++;

          if (lhs_specified && !value)
            FATAL_ERROR (_("fields and positions are numbered from 1"));

          initial = (lhs_specified ? value : 1);
          value = 0;
        }
      else if (*fieldstr == ','
               || isblank (to_uchar (*fieldstr)) || *fieldstr == '\0')
        {
          in_digits = false;
          /* Ending the string, or this field/byte sublist. */
          if (dash_found)
            {
              dash_found = false;

              if (!lhs_specified && !rhs_specified)
                FATAL_ERROR (_("invalid range with no endpoint: -"));

              /* A range.  Possibilities: -n, m-n, n-.
                 In any case, 'initial' contains the start of the range. */
              if (!rhs_specified)
                {
                  /* 'n-'.  From 'initial' to end of line. */
                  eol_range_start = initial;
                  field_found = true;
                }
              else
                {
                  /* 'm-n' or '-n' (1-n). */
                  if (value < initial)
                    FATAL_ERROR (_("invalid decreasing range"));

                  /* Is there already a range going to end of line? */
                  if (eol_range_start != 0)
                    {
                      /* Yes.  Is the new sequence already contained
                         in the old one?  If so, no processing is
                         necessary. */
                      if (initial < eol_range_start)
                        {
                          /* No, the new sequence starts before the
                             old.  Does the old range going to end of line
                             extend into the new range?  */
                          if (eol_range_start <= value)
                            {
                              /* Yes.  Simply move the end of line marker. */
                              eol_range_start = initial;
                            }
                          else
                            {
                              /* No.  A simple range, before and disjoint from
                                 the range going to end of line.  Fill it. */
                              ADD_RANGE_PAIR (rp, initial, value);
                            }

                          /* In any case, some fields were selected. */
                          field_found = true;
                        }
                    }
                  else
                    {
                      /* There is no range going to end of line. */
                      ADD_RANGE_PAIR (rp, initial, value);
                      field_found = true;
                    }
                  value = 0;
                }
            }
          else
            {
              /* A simple field number, not a range. */
              ADD_RANGE_PAIR (rp, value, value);
              value = 0;
              field_found = true;
            }

          if (*fieldstr == '\0')
            {
              break;
            }

          fieldstr++;
          lhs_specified = false;
          rhs_specified = false;
        }
      else if (ISDIGIT (*fieldstr))
        {
          /* Record beginning of digit string, in case we have to
             complain about it.  */
          static char const *num_start;
          if (!in_digits || !num_start)
            num_start = fieldstr;
          in_digits = true;

          if (dash_found)
            rhs_specified = 1;
          else
            lhs_specified = 1;

          /* Detect overflow.  */
          if (!DECIMAL_DIGIT_ACCUMULATE (value, *fieldstr - '0', size_t))
            {
              /* In case the user specified -c$(echo 2^64|bc),22,
                 complain only about the first number.  */
              /* Determine the length of the offending number.  */
              size_t len = strspn (num_start, "0123456789");
              char *bad_num = xstrndup (num_start, len);
              if (operating_mode == byte_mode)
                error (0, 0,
                       _("byte offset %s is too large"), quote (bad_num));
              else
                error (0, 0,
                       _("field number %s is too large"), quote (bad_num));
              free (bad_num);
              exit (EXIT_FAILURE);
            }

          fieldstr++;
        }
      else
        FATAL_ERROR (_("invalid byte or field list"));
    }

  max_range_endpoint = 0;
  for (i = 0; i < n_rp; i++)
    {
      if (rp[i].hi > max_range_endpoint)
        max_range_endpoint = rp[i].hi;
    }
  if (max_range_endpoint < eol_range_start)
    max_range_endpoint = eol_range_start;

  /* Allocate an array large enough so that it may be indexed by
     the field numbers corresponding to all finite ranges
     (i.e. '2-6' or '-4', but not '5-') in FIELDSTR.  */

  printable_field = xzalloc (max_range_endpoint / CHAR_BIT + 1);

  qsort (rp, n_rp, sizeof (rp[0]), compare_ranges);

  /* Set the array entries corresponding to integers in the ranges of RP.  */
  for (i = 0; i < n_rp; i++)
    {
      size_t j;
      size_t rsi_candidate;

      /* Record the range-start indices, i.e., record each start
         index that is not part of any other (lo..hi] range.  */
      rsi_candidate = complement ? rp[i].hi + 1 : rp[i].lo;
      if (output_delimiter_specified
          && !is_printable_field (rsi_candidate))
        mark_range_start (rsi_candidate);

      for (j = rp[i].lo; j <= rp[i].hi; j++)
        mark_printable_field (j);
    }

  if (output_delimiter_specified
      && !complement
      && eol_range_start && !is_printable_field (eol_range_start))
    mark_range_start (eol_range_start);

  free (rp);

  return field_found;
}

/* Read from stream STREAM, printing to standard output any selected bytes.  */

static void
cut_bytes (FILE *stream)
{
  size_t byte_idx;	/* Number of bytes in the line so far. */
  /* Whether to begin printing delimiters between ranges for the current line.
     Set after we've begun printing data corresponding to the first range.  */
  bool print_delimiter;

  byte_idx = 0;
  print_delimiter = false;
  while (1)
    {
      int c;		/* Each character from the file. */

      c = getc (stream);

      if (c == '\n')
        {
          putchar ('\n');
          byte_idx = 0;
          print_delimiter = false;
        }
      else if (c == EOF)
        {
          if (byte_idx > 0)
            putchar ('\n');
          break;
        }
      else
        {
          bool range_start;
          bool *rs = output_delimiter_specified ? &range_start : NULL;
          if (print_kth (++byte_idx, rs))
            {
              if (rs && *rs && print_delimiter)
                {
                  fwrite (output_delimiter_string, sizeof (char),
                          output_delimiter_length, stdout);
                }
              print_delimiter = true;
              putchar (c);
            }
        }
    }
}

/* Read from stream STREAM, printing to standard output any selected fields.  */

static void
cut_fields (FILE *stream)
{
  int c;
  size_t field_idx = 1;
  bool found_any_selected_field = false;
  bool buffer_first_field;

  c = getc (stream);
  if (c == EOF)
    return;

  ungetc (c, stream);

  /* To support the semantics of the -s flag, we may have to buffer
     all of the first field to determine whether it is 'delimited.'
     But that is unnecessary if all non-delimited lines must be printed
     and the first field has been selected, or if non-delimited lines
     must be suppressed and the first field has *not* been selected.
     That is because a non-delimited line has exactly one field.  */
  buffer_first_field = (suppress_non_delimited ^ !print_kth (1, NULL));

  while (1)
    {
      if (field_idx == 1 && buffer_first_field)
        {
          ssize_t len;
          size_t n_bytes;

          len = getndelim2 (&field_1_buffer, &field_1_bufsize, 0,
                            GETNLINE_NO_LIMIT, delim, '\n', stream);
          if (len < 0)
            {
              free (field_1_buffer);
              field_1_buffer = NULL;
              if (ferror (stream) || feof (stream))
                break;
              xalloc_die ();
            }

          n_bytes = len;
          assert (n_bytes != 0);

          /* If the first field extends to the end of line (it is not
             delimited) and we are printing all non-delimited lines,
             print this one.  */
          if (to_uchar (field_1_buffer[n_bytes - 1]) != delim)
            {
              if (suppress_non_delimited)
                {
                  /* Empty.  */
                }
              else
                {
                  fwrite (field_1_buffer, sizeof (char), n_bytes, stdout);
                  /* Make sure the output line is newline terminated.  */
                  if (field_1_buffer[n_bytes - 1] != '\n')
                    putchar ('\n');
                }
              continue;
            }
          if (print_kth (1, NULL))
            {
              /* Print the field, but not the trailing delimiter.  */
              fwrite (field_1_buffer, sizeof (char), n_bytes - 1, stdout);
              found_any_selected_field = true;
            }
          ++field_idx;
        }

      if (c != EOF)
        {
          if (print_kth (field_idx, NULL))
            {
              if (found_any_selected_field)
                {
                  fwrite (output_delimiter_string, sizeof (char),
                          output_delimiter_length, stdout);
                }
              found_any_selected_field = true;

              while ((c = getc (stream)) != delim && c != '\n' && c != EOF)
                {
                  putchar (c);
                }
            }
          else
            {
              while ((c = getc (stream)) != delim && c != '\n' && c != EOF)
                {
                  /* Empty.  */
                }
            }
        }

      if (c == '\n')
        {
          c = getc (stream);
          if (c != EOF)
            {
              ungetc (c, stream);
              c = '\n';
            }
        }

      if (c == delim)
        ++field_idx;
      else if (c == '\n' || c == EOF)
        {
          if (found_any_selected_field
              || !(suppress_non_delimited && field_idx == 1))
            putchar ('\n');
          if (c == EOF)
            break;
          field_idx = 1;
          found_any_selected_field = false;
        }
    }
}

static void
cut_stream (FILE *stream)
{
  if (operating_mode == byte_mode)
    cut_bytes (stream);
  else
    cut_fields (stream);
}

/* Process file FILE to standard output.
   Return true if successful.  */

static bool
cut_file (char const *file)
{
  FILE *stream;

  if (STREQ (file, "-"))
    {
      have_read_stdin = true;
      stream = stdin;
    }
  else
    {
      stream = fopen (file, "r");
      if (stream == NULL)
        {
          error (0, errno, "%s", file);
          return false;
        }
    }

  fadvise (stream, FADVISE_SEQUENTIAL);

  cut_stream (stream);

  if (ferror (stream))
    {
      error (0, errno, "%s", file);
      return false;
    }
  if (STREQ (file, "-"))
    clearerr (stream);		/* Also clear EOF. */
  else if (fclose (stream) == EOF)
    {
      error (0, errno, "%s", file);
      return false;
    }
  return true;
}

int
main (int argc, char **argv)
{
  int optc;
  bool ok;
  bool delim_specified = false;
  char *spec_list_string IF_LINT ( = NULL);

  initialize_main (&argc, &argv);
  set_program_name (argv[0]);
  setlocale (LC_ALL, "");
  bindtextdomain (PACKAGE, LOCALEDIR);
  textdomain (PACKAGE);

  atexit (close_stdout);

  operating_mode = undefined_mode;

  /* By default, all non-delimited lines are printed.  */
  suppress_non_delimited = false;

  delim = '\0';
  have_read_stdin = false;

  while ((optc = getopt_long (argc, argv, "b:c:d:f:ns", longopts, NULL)) != -1)
    {
      switch (optc)
        {
        case 'b':
        case 'c':
          /* Build the byte list. */
          if (operating_mode != undefined_mode)
            FATAL_ERROR (_("only one type of list may be specified"));
          operating_mode = byte_mode;
          spec_list_string = optarg;
          break;

        case 'f':
          /* Build the field list. */
          if (operating_mode != undefined_mode)
            FATAL_ERROR (_("only one type of list may be specified"));
          operating_mode = field_mode;
          spec_list_string = optarg;
          break;

        case 'd':
          /* New delimiter. */
          /* Interpret -d '' to mean 'use the NUL byte as the delimiter.'  */
          if (optarg[0] != '\0' && optarg[1] != '\0')
            FATAL_ERROR (_("the delimiter must be a single character"));
          delim = optarg[0];
          delim_specified = true;
          break;

        case OUTPUT_DELIMITER_OPTION:
          output_delimiter_specified = true;
          /* Interpret --output-delimiter='' to mean
             'use the NUL byte as the delimiter.'  */
          output_delimiter_length = (optarg[0] == '\0'
                                     ? 1 : strlen (optarg));
          output_delimiter_string = xstrdup (optarg);
          break;

        case 'n':
          break;

        case 's':
          suppress_non_delimited = true;
          break;

        case COMPLEMENT_OPTION:
          complement = true;
          break;

        case_GETOPT_HELP_CHAR;

        case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);

        default:
          usage (EXIT_FAILURE);
        }
    }

  if (operating_mode == undefined_mode)
    FATAL_ERROR (_("you must specify a list of bytes, characters, or fields"));

  if (delim != '\0' && operating_mode != field_mode)
    FATAL_ERROR (_("an input delimiter may be specified only\
 when operating on fields"));

  if (suppress_non_delimited && operating_mode != field_mode)
    FATAL_ERROR (_("suppressing non-delimited lines makes sense\n\
\tonly when operating on fields"));

  if (output_delimiter_specified)
    {
      range_start_ht = hash_initialize (HT_RANGE_START_INDEX_INITIAL_CAPACITY,
                                        NULL, hash_int,
                                        hash_compare_ints, NULL);
      if (range_start_ht == NULL)
        xalloc_die ();

    }

  if (! set_fields (spec_list_string))
    {
      if (operating_mode == field_mode)
        FATAL_ERROR (_("missing list of fields"));
      else
        FATAL_ERROR (_("missing list of positions"));
    }

  if (!delim_specified)
    delim = '\t';

  if (output_delimiter_string == NULL)
    {
      static char dummy[2];
      dummy[0] = delim;
      dummy[1] = '\0';
      output_delimiter_string = dummy;
      output_delimiter_length = 1;
    }

  if (optind == argc)
    ok = cut_file ("-");
  else
    for (ok = true; optind < argc; optind++)
      ok &= cut_file (argv[optind]);

  if (range_start_ht)
    hash_free (range_start_ht);

  if (have_read_stdin && fclose (stdin) == EOF)
    {
      error (0, errno, "-");
      ok = false;
    }

  exit (ok ? EXIT_SUCCESS : EXIT_FAILURE);
}