summaryrefslogtreecommitdiff
path: root/src/getlimits.c
blob: 1403ee58f506a662c7577f31cf44f90c5e166903 (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
/* getlimits - print various platform dependent limits.
   Copyright (C) 2008-2012 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 Pádraig Brady  */

#include <config.h>             /* sets _FILE_OFFSET_BITS=64 etc. */
#include <stdio.h>
#include <sys/types.h>
#include <float.h>

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

#define PROGRAM_NAME "getlimits"

#define AUTHORS proper_name_utf8 ("Padraig Brady", "P\303\241draig Brady")

#ifndef TIME_T_MAX
# define TIME_T_MAX TYPE_MAXIMUM (time_t)
#endif

#ifndef TIME_T_MIN
# define TIME_T_MIN TYPE_MINIMUM (time_t)
#endif

#ifndef SSIZE_MIN
# define SSIZE_MIN TYPE_MINIMUM (ssize_t)
#endif

#ifndef PID_T_MIN
# define PID_T_MIN TYPE_MINIMUM (pid_t)
#endif

/* These are not interesting to print.
 * Instead of these defines it would be nice to be able to do
 * #ifdef (TYPE##_MIN) in function macro below.  */
#define SIZE_MIN 0
#define UCHAR_MIN 0
#define UINT_MIN 0
#define ULONG_MIN 0
#define UINTMAX_MIN 0
#define UID_T_MIN 0
#define GID_T_MIN 0

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

      fputs (_("\
Output platform dependent limits in a format useful for shell scripts.\n\
\n\
"), stdout);
      fputs (HELP_OPTION_DESCRIPTION, stdout);
      fputs (VERSION_OPTION_DESCRIPTION, stdout);
      emit_ancillary_info ();
    }
  exit (status);
}

/* Add one to the absolute value of the number whose textual
   representation is BUF + 1.  Do this in-place, in the buffer.
   Return a pointer to the result, which is normally BUF + 1, but is
   BUF if the representation grew in size.  */
static char const *
decimal_absval_add_one (char *buf)
{
  bool negative = (buf[1] == '-');
  char *absnum = buf + 1 + negative;
  char *p = absnum + strlen (absnum);
  absnum[-1] = '0';
  while (*--p == '9')
    *p = '0';
  ++*p;
  char *result = MIN (absnum, p);
  if (negative)
    *--result = '-';
  return result;
}

int
main (int argc, char **argv)
{
  char limit[1 + MAX (INT_BUFSIZE_BOUND (intmax_t),
                      INT_BUFSIZE_BOUND (uintmax_t))];

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

  initialize_exit_failure (EXIT_FAILURE);
  atexit (close_stdout);

  parse_long_options (argc, argv, PROGRAM_NAME, PACKAGE_NAME, VERSION,
                      usage, AUTHORS, (char const *) NULL);

#define print_int(TYPE)                                                  \
  sprintf (limit + 1, "%"PRIuMAX, (uintmax_t) TYPE##_MAX);               \
  printf (#TYPE"_MAX=%s\n", limit + 1);                                  \
  printf (#TYPE"_OFLOW=%s\n", decimal_absval_add_one (limit));           \
  if (TYPE##_MIN)                                                        \
    {                                                                    \
      sprintf (limit + 1, "%"PRIdMAX, (intmax_t) TYPE##_MIN);            \
      printf (#TYPE"_MIN=%s\n", limit + 1);                              \
      printf (#TYPE"_UFLOW=%s\n", decimal_absval_add_one (limit));       \
    }

#define print_float(TYPE)                                                \
  printf (#TYPE"_MIN=%Le\n", (long double)TYPE##_MIN);                   \
  printf (#TYPE"_MAX=%Le\n", (long double)TYPE##_MAX);

  /* Variable sized ints */
  print_int (CHAR);
  print_int (SCHAR);
  print_int (UCHAR);
  print_int (SHRT);
  print_int (INT);
  print_int (UINT);
  print_int (LONG);
  print_int (ULONG);
  print_int (SIZE);
  print_int (SSIZE);
  print_int (TIME_T);
  print_int (UID_T);
  print_int (GID_T);
  print_int (PID_T);
  print_int (OFF_T);
  print_int (INTMAX);
  print_int (UINTMAX);

  /* Variable sized floats */
  print_float (FLT);
  print_float (DBL);
  print_float (LDBL);
}