UNIX编程(2)-UNIX标准化
1.ISO c
2.IEEE POSIX
3.Single UNIX Specification (XSI)
4.查看系统限制的函数
#include <unistd.h>
long sysconf(int name);
long pathconf(const char *pathname, int name);
long fpathconf(int filedes, int name);
例：打印所有可能的sysconf和pathconf的值
5.基本系统数据类型
caddr_t
core address
clock_t
counter of clock ticks (process time)
comp_t
compressed clock ticks
dev_t
device numbers (major and minor)
fd_set
file descriptor sets
fpos_t
file position
gid_t
numeric group IDs
ino_t
i-node numbers
mode_t
file type, file creation mode
nlink_t
link counts for directory entries
off_t
file sizes and offsets (signed)
pid_t
process IDs and process group IDs (signed)
ptrdiff_t
result of subtracting two pointers (signed)
rlim_t
resource limits
sig_atomic_t
data type that can be accessed atomically
sigset_t
signal set
size_t
sizes of objects (such as strings) (unsigned)
ssize_t
functions that return a count of bytes (signed) (read, write)
time_t
counter of seconds of calendar time
uid_t
numeric user IDs
wchar_t
can represent all distinct character codes
