The header file <limits.h> defines macros that expand to various limits and parameters of the standard integer types.

Type sizes
CHAR_BIT | Number of bits in a char
Character minimum and maximum values
CHAR_MIN | Minimum value of a char
CHAR_MAX | Maximum value of a char
SCHAR_MIN | Minimum value of a signed char
SCHAR_MAX | Maximum value of a signed char
UCHAR_MAX | Maximum value of an unsigned char
Short minimum and maximum values
SHRT_MIN | Minimum value of a short
SHRT_MAX | Maximum value of a short
USHRT_MAX | Maximum value of an unsigned short
Integer minimum and maximum values
INT_MIN | Minimum value of an int
INT_MAX | Maximum value of an int
UINT_MAX | Maximum value of an unsigned int
Long integer minimum and maximum values
LONG_MIN | Minimum value of a long
LONG_MAX | Maximum value of a long
ULONG_MAX | Maximum value of an unsigned long
Long long integer minimum and maximum values
LLONG_MIN | Minimum value of a long long
LLONG_MAX | Maximum value of a long long
ULLONG_MAX | Maximum value of an unsigned long long