Created
May 17, 2014 00:28
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Print various values from <limits.h> and <float.h>
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#include <stdio.h> | |
#include <stdint.h> | |
#include <limits.h> | |
#include <float.h> | |
void showInt(const char* name, size_t bytes, intmax_t max, intmax_t min, | |
uintmax_t umax); | |
/* Converting between floating-point types undoubtedly won't preserve things | |
* appropriately, so showFloat is implemented as a macro: */ | |
#define showFloat(name, form, bytes, sig, dig, epsilon, min, max, minExp, \ | |
maxExp, min10exp, max10exp) \ | |
printf(name ":\n Bytes: %zu\t\t\t\t Significand length: %d\n", bytes, sig); \ | |
printf(" Decimal precision: %-16d\t Epsilon: %.*" form "\n", dig, dig, \ | |
epsilon); \ | |
printf(" Minimum: %-30.*" form " Min radix exponent: %d\n", dig, min, \ | |
minExp); \ | |
printf(" Maximum: %-30.*" form " Max radix exponent: %d\n", dig, max, \ | |
maxExp); \ | |
printf(" Min base 10 exponent: %-16d\t Max base 10 exponent: %d\n\n", \ | |
min10exp, max10exp); | |
int main(void) { | |
#ifdef __STDC_VERSION__ | |
printf("__STDC_VERSION__ = %ld\n", __STDC_VERSION__); | |
#else | |
puts("!defined(__STDC_VERSION__)"); | |
#endif | |
printf("sizeof(void*): %zu\n", sizeof(void*)); | |
printf("Floating-point radix: %d\n", FLT_RADIX); | |
#ifdef MB_LEN_MAX | |
printf("Max bytes in a multibyte char: %d\n", MB_LEN_MAX); | |
#else | |
puts("!defined(MB_LEN_MAX)"); | |
#endif | |
putchar('\n'); | |
printf("char:\n Bits: %-16d\t\t\t Bytes: %zu\n", CHAR_BIT, sizeof(char)); | |
printf(" Minimum: %-16d\t\t Signed min: %d\n", CHAR_MIN, SCHAR_MIN); | |
printf(" Maximum: %-16d\t\t Signed max: %d\n", CHAR_MAX, SCHAR_MAX); | |
printf(" Unsigned max: %d\n\n", UCHAR_MAX); | |
showInt("short int", sizeof(short int), SHRT_MAX, SHRT_MIN, USHRT_MAX); | |
showInt("int", sizeof(int), INT_MAX, INT_MIN, UINT_MAX); | |
showInt("long int", sizeof(long int), LONG_MAX, LONG_MIN, ULONG_MAX); | |
#if __STDC_VERSION__ >= 199901L | |
showInt("long long int", sizeof(long long int), LLONG_MAX, LLONG_MIN, | |
ULLONG_MAX); | |
#endif | |
/* | |
#include <stddef.h> // ptrdiff_t, size_t, wchar_t | |
#include <signal.h> // sig_atomic_t | |
#include <wchar.h> // wchar_t, wint_t | |
showInt("[u]intptr_t", sizeof(intptr_t), INTPTR_MAX, INTPTR_MIN, UINTPTR_MAX); | |
showInt("[u]intmax_t", sizeof(intmax_t), INTMAX_MAX, INTMAX_MIN, UINTMAX_MAX); | |
showInt("ptrdiff_t", sizeof(ptrdiff_t), PTRDIFF_MAX, PTRDIFF_MIN, 0); | |
showInt("sig_atomic_t", sizeof(sig_atomic_t), SIG_ATOMIC_MAX, SIG_ATOMIC_MIN, | |
0); | |
printf("size_t:\n Bytes: %zu\t\t\t\t Maximum: %zu\n\n", sizeof(size_t), | |
SIZE_MAX); | |
showInt("wchar_t", sizeof(wchar_t), WCHAR_MAX, WCHAR_MIN, 0); | |
showInt("wint_t", sizeof(wint_t), WINT_MAX, WINT_MIN, 0); | |
*/ | |
showFloat("float", "g", sizeof(float), FLT_MANT_DIG, FLT_DIG, FLT_EPSILON, | |
FLT_MIN, FLT_MAX, FLT_MIN_EXP, FLT_MAX_EXP, FLT_MIN_10_EXP, FLT_MAX_10_EXP); | |
showFloat("double", "g", sizeof(double), DBL_MANT_DIG, DBL_DIG, DBL_EPSILON, | |
DBL_MIN, DBL_MAX, DBL_MIN_EXP, DBL_MAX_EXP, DBL_MIN_10_EXP, DBL_MAX_10_EXP); | |
showFloat("long double", "Lg", sizeof(long double), LDBL_MANT_DIG, LDBL_DIG, | |
LDBL_EPSILON, LDBL_MIN, LDBL_MAX, LDBL_MIN_EXP, LDBL_MAX_EXP, | |
LDBL_MIN_10_EXP, LDBL_MAX_10_EXP); | |
return 0; | |
} | |
void showInt(const char* name, size_t bytes, intmax_t max, intmax_t min, | |
uintmax_t umax) { | |
printf("%s:\n", name); | |
printf(" Bytes: %zu", bytes); | |
if (umax != 0) printf("\t\t\t\t Unsigned max: %ju", umax); | |
printf("\n Minimum: %-30jd Maximum: %jd\n\n", min, max); | |
} |
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