According to the POSIX standard, the *_t type corresponding to the general integer type is:
1 byte uint8_t
2 bytes uint16_t
4 bytes uint32_t
8 bytes uint64_t
1 byte uint8_t
2 bytes uint16_t
4 bytes uint32_t
8 bytes uint64_t
/* Copyright (C) 1997, 1998, 1999, 2000, 2001 Free Software Foundation, Inc. This file is part of the GNU C Library. The GNU C 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. The GNU C 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 the GNU C Library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. */ /* * ISO C99: 7.18 Integer types <stdint.h> */ #ifndef _STDINT_H #define _STDINT_H 1 #include <features.h> #include <bits/wchar.h> #include <bits/wordsize.h> /* Exact integral types. */ /* Signed. */ /* There is some amount of overlap with <sys/types.h> as known by inet code */ #ifndef __int8_t_defined # define __int8_t_defined typedef signed char int8_t; typedef short int int16_t; typedef int int32_t; # if __WORDSIZE == 64 typedef long int int64_t; # else __extension__ typedef long long int int64_t; # endif #endif /* Unsigned. */ typedef unsigned char uint8_t; typedef unsigned short int uint16_t; #ifndef __uint32_t_defined typedef unsigned int uint32_t; # define __uint32_t_defined #endif #if __WORDSIZE == 64 typedef unsigned long int uint64_t; #else __extension__ typedef unsigned long long int uint64_t; #endif /* Small types. */ /* Signed. */ typedef signed char int_least8_t; typedef short int int_least16_t; typedef int int_least32_t; #if __WORDSIZE == 64 typedef long int int_least64_t; #else __extension__ typedef long long int int_least64_t; #endif /* Unsigned. */ typedef unsigned char uint_least8_t; typedef unsigned short int uint_least16_t; typedef unsigned int uint_least32_t; #if __WORDSIZE == 64 typedef unsigned long int uint_least64_t; #else __extension__ typedef unsigned long long int uint_least64_t; #endif /* Fast types. */ /* Signed. */ typedef signed char int_fast8_t; #if __WORDSIZE == 64 typedef long int int_fast16_t; typedef long int int_fast32_t; typedef long int int_fast64_t; #else typedef int int_fast16_t; typedef int int_fast32_t; __extension__ typedef long long int int_fast64_t; #endif /* Unsigned. */ typedef unsigned char uint_fast8_t; #if __WORDSIZE == 64 typedef unsigned long int uint_fast16_t; typedef unsigned long int uint_fast32_t; typedef unsigned long int uint_fast64_t; #else typedef unsigned int uint_fast16_t; typedef unsigned int uint_fast32_t; __extension__ typedef unsigned long long int uint_fast64_t; #endif /* Types for `void *' pointers. */ #if __WORDSIZE == 64 # ifndef __intptr_t_defined typedef long int intptr_t; # define __intptr_t_defined # endif typedef unsigned long int uintptr_t; #else # ifndef __intptr_t_defined typedef int intptr_t; # define __intptr_t_defined # endif typedef unsigned int uintptr_t; #endif /* Largest integral types. */ #if __WORDSIZE == 64 typedef long int intmax_t; typedef unsigned long int uintmax_t; #else __extension__ typedef long long int intmax_t; __extension__ typedef unsigned long long int uintmax_t; #endif