#ifndef _UNISTD_H
#define _UNISTD_H
//指出符合IEEE标志1003.1实现的版本
#define _POSIX_VERSION 19808L
//chown和fchown的使用受限于进程的权限
#define _POSIX_CHOWN_RESTRICTRD
//长于(name max)的路径名将产生错误，不会自动截断
#define _POSIX_NO_TRUNC
//这个符号定义成字符值，该值将禁止终端对其的处理
#define _POSIX_VDISABLE '\0'
#define STDIN_FILEN0 0 //标准输入文件句柄
#define STDOUT_DILENO 1 // 标准输出文件句柄
#define STDERR_FILENO 2 // 标准出错文件句柄
#ifndef NULL
#define NULL ((void*)0) //空指针
#endif
//access()
#define F_OK 0 //检测文件是否存在
#define X_OK 1 //检测是否可执行
#define W_OK 2 // 检测是否可写
#define R_OK 4 //检测是否可读
//lseek()
#define SEEK_SET 0 //将文件读写指针设置位偏移值
#define SEEK_CUR 1 //将文件读写指针设置位当前值加上偏移值
#define SEEK_END 2 //将文件读写指针设置位文件长度加上偏移值
#define _SC_ARG_MAX 1 //最大变量数
#define _SC_CHILD_MAX 2 //子进程最大数
#define _SC_CLOCKS_PER_SEC 3 //每秒滴答数
#define _SC_NGROUPS_MAX 4 //最大组数
#define _SC_OPEN_MAX 5 //最大打开文件数
#define _SC_JOB_CONTROL 6 //作业控制
#define _SC_SAVED_IDS 7 //保存的标识符
#define _SC_VERSION 8 // 版本
//
#define _PC_LINK_MAX 1 // 连接最大数
#define _PC_MAX_CANON 2 //最大常规文件数
#define _PC_MAX_INPUT 3 //最大输入长度
#define _PC_NAME_MAX 4 //名称最大长度
#define _PC_PATH_MAX 5 //路径最大长度
#define _PC_PIPE_BUF 6 //管道缓冲大小
#define _PC_NO_TRUNC 7 //文件名不截断
#define _PC_VDISABLE 8 //
#define _PC_CHOWN_RESTRICTED 9 //改变宿主受限
#include<sys/stat.h>
#include<sys/times.h>
#include<sys/utsname.h>
#include<utime.h>
#ifdef _LIBRARY_
#define _NR_setup 0
#define _NR_fork 1
#define _NR_exit 2
#define _NR_read 3
#define _NR_write 4
#define _NR_open 5
#define _NR_close 6
#define _NR_waitpid 7
#define _NR_creat 8
#define _NR_link 9
#define _NR_unlink 10
#define _NR_execve 11
#define _NR_chdir 12
#define _NR_time 13
#define _NR_mknod 14
#define _NR_chmod 15
#define _NR_chwon 16
#define _NR_break 17
#define _NR_stat 18
#define _NR_lseek 19
#define _NR_getpid 20
#define _NR_mount 21
#define _NR_umount 22
#define _NR_setuid 23
#define _NR_getuid 24
#define _NR_stime 25
#define _NR_ptrace 26
#define _NR_alarm 27
#define _NR_fstat 28
#define _NR_pause 29
#define _NR_utime 30
#define _NR_stty 31
#define _NR_gtty 32
#define _NR_access 33
#define _NR_nice 34
#define _NR_ftime 35
#define _NR_sync 36
#define _NR_kill 37
#define _NR_rename 38
#define _NR_mkdir 39
#define _NR_rmdir 40
#define _NR_dup 41
#define _NR_pipe 42
#define _NR_times 43
#define _NR_prof 44
#define _NR_brk 45
#define _NR_setgid 46
#define _NR_getgid 47
#define _NR_signal 48
#define _NR_geteuid 49
#define _NR_getegid 50
#define _NR_acct 51
#define _NR_phys 52
#define _NR_lock 53
#define _NR_ioctl 54
#define _NR_fcntl 55
#define _NR_mpx 56
#define _NR_setpgid 57
#define _NR_ulimit 58
#define _NR_uname 59
#define _NR_umask 60
#define _NR_chroot 61
#define _NR_ustat 62
#define _NR_dup2 63
#define _NR_getppid 64
#define _NR_getpgrp 65
#define _NR_setsid 66
#define _NR_sigaction 67
#define _NR_sgetmask 68
#define _NR_ssetmask 69
#define _NR_setreuid 70
#define _NR_setregid 71
/*定义系统调用嵌入式汇编宏函数
*不带参数的系统调用宏函数 type name(void)
*%0-eax(res),%1-eax(_NR_##name).其中name是系统调用的名称，与上面_NR_组合形成上面的
*系统调用符号常数，从而用来对系统调用表中函数指针寻址
*返回:如果返回值大于等于0，则返回该值，否则置出错号errno，并返回-1
*/
#define _syscall0(type,name) \
type name(void) \
{ \
long _res; \
__asm__ volatile("int 0x80" \
:"=a(_res)" \
:""(_NR_##name);\ //输入系统中断调用号_NR_name
); \
if(_res>=0) \
return (type) _res; \
errno=-_res; \
return -1; \
}
/*有一个参数的系统调用函数type name(atype a)
*%0-eax(_res),%1-eax(_NR_name),%2-ebx(a)
*
*
*/
#define _syscall1(type,name,atype,a) \
type name(atype a) \
{ \
long _res; \
_asm_ volaile( \
"int 0x80" \
:"=a"(_res) \
:""(_NR_##name),"b"((long)(a)) \
); \
if(_res>0) \
return (type) _res; \
errno = -_res; \
return -1;
}
/*有两个参数的系统调用type name(atype a,btype b)
*%0-eax(res),%1-eax(_NR_name),%2-ebx(a),%3-ecx(b)
*
*/
#define _syscall2(type,name,atype a,btype b) \
type name(atype a,btype b) \
{ \
long _res; \
_asm_ volaile( \
"int 0x80" \
:"=a"(_res) \
:""(_NR_name),"b"((long)(a)),"c"((long)(b))\
); \
if(_res>=0) \
return (type) _res; \
errno =-_res; \
return -1; \
}
/*有2个参数的系统调用宏函数type name(atype a,btype b,ctype c)
*%0-eax(res),%1-eax(_NR_name),%2-ebx(a),%3-ecx(b),%4-edx(c)
*
*/
#define _syscall3(type,name,atype a,btype b,ctypec) \
type name(atype a,btype b,ctype c) \
{ \
long _res; \
_asm_ volaile( \
"int 0x80" \
:"=a"(_res) \
:""(_NR_name),"b"((long)(a)), \
"c"((long)(b)),"d"((long)(c)) \
); \
if(_res>=0) \
return (type)_res; \
errno=-_res; \
return -1; \
}
#endif
extern int errno; //出错号，全局变量
//系统调用的函数原型定义
int access(const char*filename,mode_t mode);
int acct(const char*filename);
int alarm(int sec);
int brk(void *end_data_segment);
void *sbrk(ptrdiff_t increment);
int chdir(const char*filenem);
int chmod(const char*filenem,mode_t mode);
int chown(const char*filenem,uid_t owner,gid_t group);
int chroot(const char*filenem);
int close(int fildes);
int creat(const char*filenem,mode_t mode);
int dup(int fildes);
int execve(const char*filenamem,char**argv,char**envp);
int ececv(const char*filename,char**argv);
int execvp(const char*file,char**arg);
int execl(const char*pathname,char*arg0...);
int execlp(const char*file,char*arg0...);
int execle(const char*pathname,char*arg0...);
volatile void exit(int status);
volatile void _exit(int status);
int fcntl(int fildes,int cmd...);
int fork(void);
int getpid(void);
int getuid(void);
int geteuid(void);
int getgid(void);
int getegid(void);
int ioctl(int fildes,int cmd...);
int kill(pid_t pid,int signal);
int link(const char*filenamel,const char*filename2);
int lseek(int fildes,off_t offsets,int origin);
int mknod(const char*filename,mode_t mode,dev_t dev);
int mount(const char*specialfile,const char*dir,int reflag);
int nice(int val);
int open(const char*filename,int flag...);
int pause(void);
int pipe(int *fildes);
int read(int fildes,char*buf,off_t count);
int setpgrp(void);
int setuid(uid_t uid);
int setpgid(pid_t pid,pid_t pgid);
int setgid(gid_t gid);
void (*signal(int sig,void(*fn)(int)))(int);
int stat(const char*filename,struct stat*stat_buf);
int fstat(int fildes,struct stat* stat_buf);
int stime(time_t *tptr);
int sync(void);
time_t time(time_t *tloc);
time_t times(struct tms*buf);
int ulimit(int cmd,long limit);
mode_t umask(mode_t mask);
int umount(const char*specialfile);
int uname(struct utsname*name);
int unlink(const char*filename);
int ustat(dev_t dev,struct ustat*ubuf);
int utime(const char*filename,struct utimbuf*times);
pid_t waitpid(pid_t pid,int*wait,int options);
pit_t wait(int *wait_stat);
int write(int fildes,const char*buf,off_t count);
int dup2(int oldfd,int newfd);
int getppid(void);
pid_t getpgrp(void);
pid_t setsid(void);
#endif
