summaryrefslogtreecommitdiff
path: root/src/shuf.c
blob: bb4736ca5707294affe485a1bc1f84d9ce2bd007 (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
/* Shuffle lines of text.

   Copyright (C) 2006-2012 Free Software Foundation, Inc.

   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation, either version 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 Paul Eggert.  */

#include <config.h>

#include <sys/types.h>
#include "system.h"

#include "error.h"
#include "fadvise.h"
#include "getopt.h"
#include "quote.h"
#include "quotearg.h"
#include "randint.h"
#include "randperm.h"
#include "read-file.h"
#include "stdio--.h"
#include "xstrtol.h"

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

#define AUTHORS proper_name ("Paul Eggert")

void
usage (int status)
{
  if (status != EXIT_SUCCESS)
    emit_try_help ();
  else
    {
      printf (_("\
Usage: %s [OPTION]... [FILE]\n\
  or:  %s -e [OPTION]... [ARG]...\n\
  or:  %s -i LO-HI [OPTION]...\n\
"),
              program_name, program_name, program_name);
      fputs (_("\
Write a random permutation of the input lines to standard output.\n\
\n\
"), stdout);
      fputs (_("\
Mandatory arguments to long options are mandatory for short options too.\n\
"), stdout);
      fputs (_("\
  -e, --echo                treat each ARG as an input line\n\
  -i, --input-range=LO-HI   treat each number LO through HI as an input line\n\
  -n, --head-count=COUNT    output at most COUNT lines\n\
  -o, --output=FILE         write result to FILE instead of standard output\n\
      --random-source=FILE  get random bytes from FILE\n\
  -z, --zero-terminated     end lines with 0 byte, not newline\n\
"), stdout);
      fputs (HELP_OPTION_DESCRIPTION, stdout);
      fputs (VERSION_OPTION_DESCRIPTION, stdout);
      fputs (_("\
\n\
With no FILE, or when FILE is -, read standard input.\n\
"), stdout);
      emit_ancillary_info ();
    }

  exit (status);
}

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

static struct option const long_opts[] =
{
  {"echo", no_argument, NULL, 'e'},
  {"input-range", required_argument, NULL, 'i'},
  {"head-count", required_argument, NULL, 'n'},
  {"output", required_argument, NULL, 'o'},
  {"random-source", required_argument, NULL, RANDOM_SOURCE_OPTION},
  {"zero-terminated", no_argument, NULL, 'z'},
  {GETOPT_HELP_OPTION_DECL},
  {GETOPT_VERSION_OPTION_DECL},
  {0, 0, 0, 0},
};

static bool
input_numbers_option_used (size_t lo_input, size_t hi_input)
{
  return ! (lo_input == SIZE_MAX && hi_input == 0);
}

static void
input_from_argv (char **operand, int n_operands, char eolbyte)
{
  char *p;
  size_t size = n_operands;
  int i;

  for (i = 0; i < n_operands; i++)
    size += strlen (operand[i]);
  p = xmalloc (size);

  for (i = 0; i < n_operands; i++)
    {
      char *p1 = stpcpy (p, operand[i]);
      operand[i] = p;
      p = p1;
      *p++ = eolbyte;
    }

  operand[n_operands] = p;
}

/* Return the start of the next line after LINE.  The current line
   ends in EOLBYTE, and is guaranteed to end before LINE + N.  */

static char *
next_line (char *line, char eolbyte, size_t n)
{
  char *p = memchr (line, eolbyte, n);
  return p + 1;
}

/* Read data from file IN.  Input lines are delimited by EOLBYTE;
   silently append a trailing EOLBYTE if the file ends in some other
   byte.  Store a pointer to the resulting array of lines into *PLINE.
   Return the number of lines read.  Report an error and exit on
   failure.  */

static size_t
read_input (FILE *in, char eolbyte, char ***pline)
{
  char *p;
  char *buf = NULL;
  size_t used;
  char *lim;
  char **line;
  size_t i;
  size_t n_lines;

  if (!(buf = fread_file (in, &used)))
    error (EXIT_FAILURE, errno, _("read error"));

  if (used && buf[used - 1] != eolbyte)
    buf[used++] = eolbyte;

  lim = buf + used;

  n_lines = 0;
  for (p = buf; p < lim; p = next_line (p, eolbyte, lim - p))
    n_lines++;

  *pline = line = xnmalloc (n_lines + 1, sizeof *line);

  line[0] = p = buf;
  for (i = 1; i <= n_lines; i++)
    line[i] = p = next_line (p, eolbyte, lim - p);

  return n_lines;
}

static int
write_permuted_output (size_t n_lines, char * const *line, size_t lo_input,
                       size_t const *permutation, char eolbyte)
{
  size_t i;

  if (line)
    for (i = 0; i < n_lines; i++)
      {
        char * const *p = line + permutation[i];
        size_t len = p[1] - p[0];
        if (fwrite (p[0], sizeof *p[0], len, stdout) != len)
          return -1;
      }
  else
    for (i = 0; i < n_lines; i++)
      {
        unsigned long int n = lo_input + permutation[i];
        if (printf ("%lu%c", n, eolbyte) < 0)
          return -1;
      }

  return 0;
}

int
main (int argc, char **argv)
{
  bool echo = false;
  size_t lo_input = SIZE_MAX;
  size_t hi_input = 0;
  size_t head_lines = SIZE_MAX;
  char const *outfile = NULL;
  char *random_source = NULL;
  char eolbyte = '\n';
  char **input_lines = NULL;

  int optc;
  int n_operands;
  char **operand;
  size_t n_lines;
  char **line;
  struct randint_source *randint_source;
  size_t *permutation;

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

  atexit (close_stdout);

  while ((optc = getopt_long (argc, argv, "ei:n:o:z", long_opts, NULL)) != -1)
    switch (optc)
      {
      case 'e':
        echo = true;
        break;

      case 'i':
        {
          unsigned long int argval = 0;
          char *p = strchr (optarg, '-');
          char const *hi_optarg = optarg;
          bool invalid = !p;

          if (input_numbers_option_used (lo_input, hi_input))
            error (EXIT_FAILURE, 0, _("multiple -i options specified"));

          if (p)
            {
              *p = '\0';
              invalid = ((xstrtoul (optarg, NULL, 10, &argval, NULL)
                          != LONGINT_OK)
                         || SIZE_MAX < argval);
              *p = '-';
              lo_input = argval;
              hi_optarg = p + 1;
            }

          invalid |= ((xstrtoul (hi_optarg, NULL, 10, &argval, NULL)
                       != LONGINT_OK)
                      || SIZE_MAX < argval);
          hi_input = argval;
          n_lines = hi_input - lo_input + 1;
          invalid |= ((lo_input <= hi_input) == (n_lines == 0));
          if (invalid)
            error (EXIT_FAILURE, 0, _("invalid input range %s"),
                   quote (optarg));
        }
        break;

      case 'n':
        {
          unsigned long int argval;
          strtol_error e = xstrtoul (optarg, NULL, 10, &argval, NULL);

          if (e == LONGINT_OK)
            head_lines = MIN (head_lines, argval);
          else if (e != LONGINT_OVERFLOW)
            error (EXIT_FAILURE, 0, _("invalid line count %s"),
                   quote (optarg));
        }
        break;

      case 'o':
        if (outfile && !STREQ (outfile, optarg))
          error (EXIT_FAILURE, 0, _("multiple output files specified"));
        outfile = optarg;
        break;

      case RANDOM_SOURCE_OPTION:
        if (random_source && !STREQ (random_source, optarg))
          error (EXIT_FAILURE, 0, _("multiple random sources specified"));
        random_source = optarg;
        break;

      case 'z':
        eolbyte = '\0';
        break;

      case_GETOPT_HELP_CHAR;
      case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
      default:
        usage (EXIT_FAILURE);
      }

  n_operands = argc - optind;
  operand = argv + optind;

  if (echo)
    {
      if (input_numbers_option_used (lo_input, hi_input))
        error (EXIT_FAILURE, 0, _("cannot combine -e and -i options"));
      input_from_argv (operand, n_operands, eolbyte);
      n_lines = n_operands;
      line = operand;
    }
  else if (input_numbers_option_used (lo_input, hi_input))
    {
      if (n_operands)
        {
          error (0, 0, _("extra operand %s"), quote (operand[0]));
          usage (EXIT_FAILURE);
        }
      n_lines = hi_input - lo_input + 1;
      line = NULL;
    }
  else
    {
      switch (n_operands)
        {
        case 0:
          break;

        case 1:
          if (! (STREQ (operand[0], "-") || freopen (operand[0], "r", stdin)))
            error (EXIT_FAILURE, errno, "%s", operand[0]);
          break;

        default:
          error (0, 0, _("extra operand %s"), quote (operand[1]));
          usage (EXIT_FAILURE);
        }

      fadvise (stdin, FADVISE_SEQUENTIAL);

      n_lines = read_input (stdin, eolbyte, &input_lines);
      line = input_lines;
    }

  head_lines = MIN (head_lines, n_lines);

  randint_source = randint_all_new (random_source,
                                    randperm_bound (head_lines, n_lines));
  if (! randint_source)
    error (EXIT_FAILURE, errno, "%s", quotearg_colon (random_source));

  /* Close stdin now, rather than earlier, so that randint_all_new
     doesn't have to worry about opening something other than
     stdin.  */
  if (! (echo || input_numbers_option_used (lo_input, hi_input))
      && (fclose (stdin) != 0))
    error (EXIT_FAILURE, errno, _("read error"));

  permutation = randperm_new (randint_source, head_lines, n_lines);

  if (outfile && ! freopen (outfile, "w", stdout))
    error (EXIT_FAILURE, errno, "%s", quotearg_colon (outfile));
  if (write_permuted_output (head_lines, line, lo_input, permutation, eolbyte)
      != 0)
    error (EXIT_FAILURE, errno, _("write error"));

#ifdef lint
  free (permutation);
  randint_all_free (randint_source);
  if (input_lines)
    {
      free (input_lines[0]);
      free (input_lines);
    }
#endif

  return EXIT_SUCCESS;
}