CentOS7中的系统类型对应的真实类型

总结了CentOs7中，系统类型的真是类型及对应的头文件，列于下表。此表中 int为32位，long 为 32位，long int 为32位， short int为16位。

 

Type	Real Type	header file	Description
clock_t	long int	time.h	counter of clock ticks (process time) (Section 1.10)
comp_t			compressed clock ticks (not defined by POSIX.1; see Section 8.14)
dev_t	unsigned long int	types.h	device numbers (major and minor) (Section 4.24)
fd_set	struct{ #ifdef __USE_XOPEN 　　long int fds_bits[__FD_SETSIZE / __NFDBITS]; # define __FDS_BITS(set) ((set)->fds_bits) #else 　　long int __fds_bits[__FD_SETSIZE / __NFDBITS]; # define __FDS_BITS(set) ((set)->__fds_bits) #endif }	sys/select.h	file descriptor sets (Section 14.4.1)
fpos_t	struct{long int __pos; 　　　　struct{ 　　　　　　　　int __count; 　　　　　　　　union{ 　　　　　　　　　　　　unsigned int __wch; 　　　　　　　　　　　　 char __wchb[4]; 　　　　　　　　} 　　　　} __state; }	stdio.h	file position (Section 5.10)
gid_t	unsigned int	types.h	numeric group IDs
ino_t	unsigned long int	types.h	i-node numbers
mode_t	unsigned int	types.h	file type, file creation mode (Section 4.5)
nlink_t	unsigned long int	types.h	link counts for directory entries
off_t	long int	types.h	file sizes and offsets (signed) (lseek, Section 3.6)
pid_t	int	types.h	process IDs and process group IDs (signed) (Sections 8.2 and 9.4)
pthread_t	unsigned long int	pthreadtypes.h	thread IDs (Section 11.3)
ptrdiff_t	long int	stddef.h	result of subtracting two pointers (signed)
rlim_t	unsigned long int	sys/resource.h	resource limits (Section 7.11)
sig_atomic_t	int	signal.h	data type that can be accessed atomically (Section 10.15)
sigset_t	struct{ 　　unsigned long int __val[SIGSET_NWORDS]; }	signal.h	signal set (Section 10.11)
size_t	unsigned long int	stddef.h	sizes of objects (such as strings) (unsigned) (Section 3.7)
ssize_t	long int	types.h	functions that return a count of bytes (signed) (read, write, Section 3.7)
time_t	long int	time.h	counter of seconds of calendar time (Section 1.10)
uid_t	unsigned int	types.h	numeric user IDs
wchar_t	int		can represent all distinct character codes