limits.h

limits.h is the header of the general purpose standard library of C programming language which includes definitions of the characteristics of variable types. The values are implementation specific, but may not be of lower magnitude than certain specified values in a conforming C implementation.

Member constants

Name	Description	Minimum value*
CHAR_BIT	Number of bits in a byte	+8
SCHAR_MIN	Minimum value for a signed char	-128
SCHAR_MAX	Maximum value for a signed char	+127
UCHAR_MAX	Maximum value for an unsigned char	+255
CHAR_MIN	Minimum value for a char	-128 (if char is represented as a signed char; otherwise 0)
CHAR_MAX	Maximum value for a char	+127 (if char is represented as a signed char; otherwise +255)
MB_LEN_MAX	Maximum multi byte length of a character across all locales	+127
SHRT_MIN	Minimum value for a short int	-32,768
SHRT_MAX	Maximum value for a short int	+32,767
USHRT_MAX	Maximum value for an unsigned short int	+65,535
INT_MIN	Minimum value for an int	-2,147,483,648
INT_MAX	Maximum value for an int	+2,147,483,647
UINT_MAX	Maximum value for an unsigned int	+4,294,967,295
LONG_MIN	Minimum value for a long int	-2,147,483,647
LONG_MAX	Maximum value for a long int	+2,147,483,647
ULONG_MAX	Maximum value for an unsigned long int	+4,294,967,295
LLONG_MIN	Minimum value for a long long int	-9,223,372,036,854,775,807
LLONG_MAX	Maximum value for a long long int	+9,223,372,036,854,775,807
ULLONG_MAX	Maximum value for an unsigned long long int	+18,446,744,073,709,551,615

• *Notes on minimum value: The magnitude of this column is the minimum magnitude for this constant. Negative values represent the minimum value representable in one's complement and sign-magnitude forms. Most implementations will have larger magnitudes for at least some of these numbers. For example, many implementations have both INT_MAX and LONG_MAX equal to +2,147,483,647; and INT_MIN and LONG_MIN equal to -2,147,483,648. Many DSPs have CHAR_BIT equal to 16 or more[1][2].

See also

C standard library

Float.h - Limits on floating-point numbers

External links

• Enquire: A program for automatically generating limits.h, and for checking that the values in an existing limits.h are correct

References

• C Guide--2.5 limits.h, accessed in September 2006.