src/getlimits.c

   1 /* getlimits - print various platform dependent limits.
   2    Copyright (C) 2008-2012 Free Software Foundation, Inc.
   3
   4    This program is free software: you can redistribute it and/or modify
   5    it under the terms of the GNU General Public License as published by
   6    the Free Software Foundation, either version 3 of the License, or
   7    (at your option) any later version.
   8
   9    This program is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12    GNU General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  16
  17 /* Written by Pádraig Brady  */
  18
  19 #include <config.h>             /* sets _FILE_OFFSET_BITS=64 etc. */
  20 #include <stdio.h>
  21 #include <sys/types.h>
  22 #include <float.h>
  23
  24 #include "system.h"
  25 #include "long-options.h"
  26
  27 #define PROGRAM_NAME "getlimits"
  28
  29 #define AUTHORS proper_name_utf8 ("Padraig Brady", "P\303\241draig Brady")
  30
  31 #ifndef TIME_T_MAX
  32 # define TIME_T_MAX TYPE_MAXIMUM (time_t)
  33 #endif
  34
  35 #ifndef TIME_T_MIN
  36 # define TIME_T_MIN TYPE_MINIMUM (time_t)
  37 #endif
  38
  39 #ifndef SSIZE_MIN
  40 # define SSIZE_MIN TYPE_MINIMUM (ssize_t)
  41 #endif
  42
  43 #ifndef PID_T_MIN
  44 # define PID_T_MIN TYPE_MINIMUM (pid_t)
  45 #endif
  46
  47 /* These are not interesting to print.
  48  * Instead of these defines it would be nice to be able to do
  49  * #ifdef (TYPE##_MIN) in function macro below.  */
  50 #define SIZE_MIN 0
  51 #define UCHAR_MIN 0
  52 #define UINT_MIN 0
  53 #define ULONG_MIN 0
  54 #define UINTMAX_MIN 0
  55 #define UID_T_MIN 0
  56 #define GID_T_MIN 0
  57
  58 void
  59 usage (int status)
  60 {
  61   if (status != EXIT_SUCCESS)
  62     emit_try_help ();
  63   else
  64     {
  65       printf (_("\
  66 Usage: %s\n\
  67 "), program_name);
  68
  69       fputs (_("\
  70 Output platform dependent limits in a format useful for shell scripts.\n\
  71 \n\
  72 "), stdout);
  73       fputs (HELP_OPTION_DESCRIPTION, stdout);
  74       fputs (VERSION_OPTION_DESCRIPTION, stdout);
  75       emit_ancillary_info ();
  76     }
  77   exit (status);
  78 }
  79
  80 /* Add one to the absolute value of the number whose textual
  81    representation is BUF + 1.  Do this in-place, in the buffer.
  82    Return a pointer to the result, which is normally BUF + 1, but is
  83    BUF if the representation grew in size.  */
  84 static char const *
  85 decimal_absval_add_one (char *buf)
  86 {
  87   bool negative = (buf[1] == '-');
  88   char *absnum = buf + 1 + negative;
  89   char *p = absnum + strlen (absnum);
  90   absnum[-1] = '0';
  91   while (*--p == '9')
  92     *p = '0';
  93   ++*p;
  94   char *result = MIN (absnum, p);
  95   if (negative)
  96     *--result = '-';
  97   return result;
  98 }
  99
 100 int
 101 main (int argc, char **argv)
 102 {
 103   char limit[1 + MAX (INT_BUFSIZE_BOUND (intmax_t),
 104                       INT_BUFSIZE_BOUND (uintmax_t))];
 105
 106   initialize_main (&argc, &argv);
 107   set_program_name (argv[0]);
 108   setlocale (LC_ALL, "");
 109   bindtextdomain (PACKAGE, LOCALEDIR);
 110   textdomain (PACKAGE);
 111
 112   initialize_exit_failure (EXIT_FAILURE);
 113   atexit (close_stdout);
 114
 115   parse_long_options (argc, argv, PROGRAM_NAME, PACKAGE_NAME, VERSION,
 116                       usage, AUTHORS, (char const *) NULL);
 117
 118 #define print_int(TYPE)                                                  \
 119   sprintf (limit + 1, "%"PRIuMAX, (uintmax_t) TYPE##_MAX);               \
 120   printf (#TYPE"_MAX=%s\n", limit + 1);                                  \
 121   printf (#TYPE"_OFLOW=%s\n", decimal_absval_add_one (limit));           \
 122   if (TYPE##_MIN)                                                        \
 123     {                                                                    \
 124       sprintf (limit + 1, "%"PRIdMAX, (intmax_t) TYPE##_MIN);            \
 125       printf (#TYPE"_MIN=%s\n", limit + 1);                              \
 126       printf (#TYPE"_UFLOW=%s\n", decimal_absval_add_one (limit));       \
 127     }
 128
 129 #define print_float(TYPE)                                                \
 130   printf (#TYPE"_MIN=%Le\n", (long double)TYPE##_MIN);                   \
 131   printf (#TYPE"_MAX=%Le\n", (long double)TYPE##_MAX);
 132
 133   /* Variable sized ints */
 134   print_int (CHAR);
 135   print_int (SCHAR);
 136   print_int (UCHAR);
 137   print_int (SHRT);
 138   print_int (INT);
 139   print_int (UINT);
 140   print_int (LONG);
 141   print_int (ULONG);
 142   print_int (SIZE);
 143   print_int (SSIZE);
 144   print_int (TIME_T);
 145   print_int (UID_T);
 146   print_int (GID_T);
 147   print_int (PID_T);
 148   print_int (OFF_T);
 149   print_int (INTMAX);
 150   print_int (UINTMAX);
 151
 152   /* Variable sized floats */
 153   print_float (FLT);
 154   print_float (DBL);
 155   print_float (LDBL);
 156 }