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/*
* Standalone program to nicely display current C data type limits and sizes.
*
* Copyright (C) 2008-2012 George Gesslein II
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
The chief copyright holder can be contacted at gesslein@mathomatic.org, or
George Gesslein II, P.O. Box 224, Lansing, NY 14882-0224 USA.
*/
/*
* Compile with:
*
* cc limits.c -o limits
*
* then type "./limits".
*/
#include <stdio.h>
#include <stdlib.h>
#include <limits.h>
#include <float.h>
int
main(void)
{
float xf = 1.0;
double xd = 1.0;
#ifdef LDBL_EPSILON
long double xl = 1.0;
#endif
#ifdef __VERSION__
#ifdef __GNUC__
printf("GNU ");
#endif
printf("C Compiler version: %s\n\n", __VERSION__);
#endif
printf("C compiler integer limits:\n");
printf("--------------------------\n");
printf("CHAR_BIT: Bits of type char: %d\n", CHAR_BIT);
printf("sizeof(char) = %u bytes.\n", (unsigned) sizeof(char));
printf("sizeof(char *) = %u bytes.\n", (unsigned) sizeof(char *));
if (CHAR_MIN < 0) {
printf("Current type char is signed.\n");
} else {
printf("Current type char is unsigned.\n");
}
printf("CHAR_MAX: Maximum numeric value of type char: %d\n", CHAR_MAX);
printf("CHAR_MIN: Minimum numeric value of type char: %d\n\n", CHAR_MIN);
printf("SCHAR_MAX: Maximum value of type signed char: %d\n", SCHAR_MAX);
printf("SCHAR_MIN: Minimum value of type signed char: %d\n\n", SCHAR_MIN);
printf("UCHAR_MAX: Maximum value of type unsigned char: %u\n\n", (unsigned) UCHAR_MAX);
printf("sizeof(short) = %u bytes.\n", (unsigned) sizeof(short));
printf("SHRT_MAX: Maximum value of type short: %d\n", SHRT_MAX);
printf("SHRT_MIN: Minimum value of type short: %d\n\n", SHRT_MIN);
printf("USHRT_MAX: Maximum value of type unsigned short: %u\n\n", (unsigned) USHRT_MAX);
printf("sizeof(int) = %u bytes.\n", (unsigned) sizeof(int));
printf("INT_MAX: Maximum value of type int: %d\n", INT_MAX);
printf("INT_MIN: Minimum value of type int: %d\n\n", INT_MIN);
printf("UINT_MAX: Maximum value of type unsigned int: %u\n\n", UINT_MAX);
printf("sizeof(long) = %u bytes.\n", (unsigned) sizeof(long));
printf("LONG_MAX: Maximum value of type long: %ld\n", LONG_MAX);
printf("LONG_MIN: Minimum value of type long: %ld\n\n", LONG_MIN);
printf("ULONG_MAX: Maximum value of type unsigned long: %lu\n\n", ULONG_MAX);
#ifdef ULLONG_MAX
printf("sizeof(long long) = %u bytes.\n", (unsigned) sizeof(long long));
printf("LLONG_MAX: Maximum value of type long long: %lld\n", LLONG_MAX);
printf("LLONG_MIN: Minimum value of type long long: %lld\n\n", LLONG_MIN);
printf("ULLONG_MAX: Maximum value of type unsigned long long: %llu\n\n", ULLONG_MAX);
#else
printf("Type \"long long\" not supported by this C compiler.\n\n");
#endif
printf("\nC compiler floating point limits:\n");
printf("---------------------------------\n");
printf("sizeof(float) = %u bytes.\n", (unsigned) sizeof(float));
printf("FLT_DIG: Decimal digits of precision for float: %d\n", FLT_DIG);
printf("sizeof(double) = %u bytes.\n", (unsigned) sizeof(double));
printf("DBL_DIG: Decimal digits of precision for double: %d\n", DBL_DIG);
#ifdef LDBL_DIG
printf("sizeof(long double) = %u bytes.\n", (unsigned) sizeof(long double));
printf("LDBL_DIG: Decimal digits of precision for long double: %d\n", LDBL_DIG);
#endif
printf("\nFLT_MAX: Maximum value of float: %g\n", FLT_MAX);
printf("FLT_MIN: Minimum value of float: %g\n\n", FLT_MIN);
printf("DBL_MAX: Maximum value of double: %g\n", DBL_MAX);
printf("DBL_MIN: Minimum value of double: %g\n\n", DBL_MIN);
#ifdef LDBL_MAX
printf("LDBL_MAX: Maximum value of long double: %Lg\n", LDBL_MAX);
printf("LDBL_MIN: Minimum value of long double: %Lg\n\n", LDBL_MIN);
#else
printf("Type \"long double\" not supported by this C compiler.\n\n");
#endif
printf("Epsilon is the smallest x such that 1.0 + x != 1.0\n");
printf("FLT_EPSILON: Float epsilon: %g", FLT_EPSILON);
xf += (FLT_EPSILON / 2.0);
if (xf == 1.0) {
xf += FLT_EPSILON;
if (xf > 1.0) {
printf(" verified.");
}
}
printf("\n");
printf("DBL_EPSILON: Double epsilon: %g", DBL_EPSILON);
xd += (DBL_EPSILON / 2.0);
if (xd == 1.0) {
xd += DBL_EPSILON;
if (xd > 1.0) {
printf(" verified.");
}
}
printf("\n");
#ifdef LDBL_EPSILON
printf("LDBL_EPSILON: Long double epsilon: %Lg", LDBL_EPSILON);
xl += (LDBL_EPSILON / 2.0);
if (xl == 1.0) {
xl += LDBL_EPSILON;
if (xl > 1.0) {
printf(" verified.");
}
}
printf("\n");
#endif
printf("\nEnd of limits program output.\n");
return 0;
}
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