Linux basic data type size--int,char,long int,long long int

Transferred from: http://paddy-w.iteye.com/blog/1403217

In the Linux operating system using GCC programming, the current general processor is 32-bit word width, the following is the/usr/include/limit.h file on the Linux data type limitations and storage byte size description.
/* We have #include_next.  Define ANSI <limits.h> for standard 32-bit words. */
/* These assume 8-bit ' char ' s, 16-bit ' short int ' s, and 32-bit ' int ' s and ' long int ' s. */
1.char Data types
The char type data occupies a memory space of 8 bits. Where is the value range of the symbolic character type variable? 128~127, the value range for unsigned character variables is 0~255. The restrictions are as follows:
/* Number of bits in a ' char '. */
# define Char_bit 8//Of bytes occupied
/* Minimum and maximum values a ' signed char ' can hold. *///signed character type range
# define SCHAR_MIN (-128)
# define Schar_max 127
/* Maximum value a ' unsigned char ' can hold. (Minimum is 0.) *//unsigned character range
# define UCHAR_MAX 255
/* Minimum and maximum values a ' char ' can hold. */
# ifdef __CHAR_UNSIGNED__
# define Char_min 0
# define Char_max Uchar_max
# Else
# define Char_min schar_min
# define Char_max Schar_max
# endif
2.short int data type
The short int type data occupies a memory space of 16 bits. Where is the signed short integer variable value range? 32768~32767, unsigned short integer variables have a range of 0~65535. The restrictions are as follows:
/* Minimum and maximum values a ' signed short int ' can hold. *///Signed short-integer range
# define Shrt_min (-32768)
# define Shrt_max 32767
/* Maximum value an ' unsigned short int ' can hold. (Minimum is 0.) */
Unsigned short-integer range
# define Ushrt_max 65535
The 3.int data type int type data occupies a memory space of 32 bits. The value range of the signed integer variable is -2147483648~2147483647, and the value range of the unsigned integer variable is 0~4294967295u. The restrictions are as follows:
/* Minimum and maximum values a ' signed int ' can hold. *//Shaping Range
# define INT_MIN (-int_max-1)
# define Int_max 2147483647
/* Maximum value an ' unsigned int ' can hold. (Minimum is 0.) */
Unsigned shaping range # define Uint_max 4294967295U
4.long int data type
As the macro __wordsize value changes, the size of the long int data type also changes. If the value of __wordsize is 32, a long int is the same as the int type and occupies 32 bits. In the Linux gcc4.0-i386 version, the value of __wordsize is 32 by default. It is defined as follows:
Come from/usr/include/bits/wordsize.h
#define __WORDSIZE 32
On a 64-bit machine, if the value of __wordsize is zero, the long int data occupies a memory space of 64 bits. There is a long integer variable value range of -9223372036854775808l~9223372036854775807l, unsigned long integer variable value range is 0~18446744073709551615ul. The restrictions are as follows:
/* Minimum and maximum values a ' signed long int ' can hold. *///Signed Long shaping range
# if __wordsize = = 64
# define Long_max 9223372036854775807L
# Else
# define Long_max 2147483647L
# endif
# define LONG_MIN (-long_max-1l)

/* Maximum value a ' unsigned long int ' can hold. (Minimum is 0.) *///unsigned long shaping range
# if __wordsize = = 64
# define Ulong_max 18446744073709551615UL
# Else
# define Ulong_max 4294967295UL
# endif
5.long long int data type
In C99, a long long int data type is also defined. Its data types are limited as follows:
# ifdef __USE_ISOC99
/* Minimum and maximum values a ' signed long long int ' can hold. *///unsigned long shaping range
# define Llong_max 9223372036854775807LL
# define LLONG_MIN (-LLONG_MAX-1LL)
/* Maximum value a ' unsigned long long int ' can hold. (Minimum is 0.) *///signed long shaping range
# define Ullong_max 18446744073709551615ULL
# endif/* ISO C99 */

Linux basic data type size--int,char,long int,long long int