summaryrefslogtreecommitdiff
path: root/src/yes.c
blob: 3b7b4c62198671cc9321bb9c4cf1a2f57d7c23ee (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
/* yes - output a string repeatedly until killed
   Copyright (C) 1991-2015 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/>.  */

/* David MacKenzie <djm@gnu.ai.mit.edu> */

#include <config.h>
#include <stdio.h>
#include <sys/types.h>
#include <getopt.h>

#include "system.h"

#include "error.h"
#include "long-options.h"

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

#define AUTHORS proper_name ("David MacKenzie")

void
usage (int status)
{
  if (status != EXIT_SUCCESS)
    emit_try_help ();
  else
    {
      printf (_("\
Usage: %s [STRING]...\n\
  or:  %s OPTION\n\
"),
              program_name, program_name);

      fputs (_("\
Repeatedly output a line with all specified STRING(s), or 'y'.\n\
\n\
"), stdout);
      fputs (HELP_OPTION_DESCRIPTION, stdout);
      fputs (VERSION_OPTION_DESCRIPTION, stdout);
      emit_ancillary_info (PROGRAM_NAME);
    }
  exit (status);
}

int
main (int argc, char **argv)
{
  char buf[BUFSIZ];
  char *pbuf = buf;
  int i;

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

  atexit (close_stdout);

  parse_long_options (argc, argv, PROGRAM_NAME, PACKAGE_NAME, Version,
                      usage, AUTHORS, (char const *) NULL);
  if (getopt_long (argc, argv, "+", NULL, NULL) != -1)
    usage (EXIT_FAILURE);

  if (argc <= optind)
    {
      optind = argc;
      argv[argc++] = bad_cast ("y");
    }

  /* Buffer data locally once, rather than having the
     large overhead of stdio buffering each item.  */
  for (i = optind; i < argc; i++)
    {
      size_t len = strlen (argv[i]);
      if (BUFSIZ < len || BUFSIZ - len <= pbuf - buf)
        break;
      memcpy (pbuf, argv[i], len);
      pbuf += len;
      *pbuf++ = i == argc - 1 ? '\n' : ' ';
    }
  if (i == argc)
    {
      size_t line_len = pbuf - buf;
      size_t lines = BUFSIZ / line_len;
      while (--lines)
        {
          memcpy (pbuf, pbuf - line_len, line_len);
          pbuf += line_len;
        }
    }

  /* The normal case is to continuously output the local buffer.  */
  while (i == argc)
    {
      if (write (STDOUT_FILENO, buf, pbuf - buf) == -1)
        {
          error (0, errno, _("standard output"));
          return EXIT_FAILURE;
        }
    }

  /* If the data doesn't fit in BUFSIZ then output
     what we've buffered, and iterate over the remaining items.  */
  while (i != argc)
    {
      int j;
      if ((pbuf - buf) && fwrite (buf, pbuf - buf, 1, stdout) != 1)
        {
          error (0, errno, _("standard output"));
          return EXIT_FAILURE;
        }
      for (j = i; j < argc; j++)
        if (fputs (argv[j], stdout) == EOF
            || putchar (j == argc - 1 ? '\n' : ' ') == EOF)
          {
            error (0, errno, _("standard output"));
            return EXIT_FAILURE;
          }
    }
}