#ifndef UNISTD_H
#define UNISTD_H

#include <sys/types.h>
#include <stdint.h>
#include <stddef.h>

#define STDIN_FILENO    0
#define STDOUT_FILENO   1
#define STDERR_FILENO   2

#define SEEK_SET        0
#define SEEK_CUR        1
#define SEEK_END        2
#define SEEK_DATA       3
#define SEEK_HOLE       4

#define NULL            ((void*)0)

#define F_OK            0
#define R_OK            4
#define W_OK            2
#define X_OK            1

int pipe();
int pipe2();
int close(int fildes);
int dup(int fildes);
int dup2();
int dup3();
off_t lseek();
int fsync();
int fdatasync();

ssize_t read(int fildes, void *buf, size_t nbyte);
ssize_t write(int fildes, const void *buf, size_t nbyte);
ssize_t pread(int fildes, void *buf, size_t nbyte, off_t offset);
ssize_t pwrite(int fildes, const void *buf, size_t nbyte, off_t offset);

int chown(const char *path, uid_t owner, gid_t group);
int fchown(int fildes, uid_t owner, gid_t group);
int lchown(const char *path, uid_t owner, gid_t group);
int fchownat(int fildes, const char *path, uid_t owner, gid_t group);

int link(const char *target, const char *lpath);
int linkat(int target_fd, const char *tpath, int link_fd, const char *lpath);
int symlink(const char *target, const char *lpath);
int symlinkat(const char *target, int fildes, const char *lpath);
ssize_t readlink(const char* __restrict path, char* __restrict buf, size_t bufsz);
ssize_t readlinkat(int fildes, const char* __restrict path, char* __restrict buf, size_t bufsz);
int unlink(const char *lpath);
int unlinkat(int fildes, const char *lpath, int flag);
int rmdir(const char *path);
int truncate(const char *path, off_t length);
int ftruncate(int fildes, off_t length);

int access(const char *path, int amode);
int faccessat(int fildes, const char *path, int amode, int flag);

int chdir(const char *path);
int fchdir(int fildes);
char* getcwd(char *buf, size_t bufsz);

unsigned int alarm(unsigned int seconds);
unsigned int sleep(unsigned int seconds);
unsigned int ualarm(useconds_t usec);
unsigned int usleep(useconds_t usec);
int pause(void);

pid_t fork(void);
pid_t vfork(void);
void _exit(int status);
int execve(const char *pathname, char* const argv[], char* const envp[]);
int execv(const char *pathname, char* const argv[]);
int execle(const char *pathname, const char *argv, ...);
int execl(const char *pathname, const char *argv, ...);
int execvp(const char *pathname, char* const argv[]);
int execvpe(const char *pathname, char* const argv[], char* const envp[]);
int execlp(const char *pathname, char* const argv[], ...);
int fexecve(int fildes, char* const argv[], char* const envp[]);

pid_t getpid(void);
pid_t getppid(void);
pid_t getpgrp(void);
pid_t getpgid(pid_t);
int setpgid(pid_t pid, pid_t pgid);
pid_t setsid(void);
pid_t getsid(pid_t pid);
char* ttyname(int fildes);
int ttyname_r(int fildes, char *buf, size_t bufsz);
int isatty(int fildes);
pid_t tcgetpgrp(int fildes);

uid_t getuid(void);
uid_t geteuid(void);
gid_t getgid(void);
gid_t getegid(void);
int getgroups(int gidsetsize, gid_t grouplist[]);
int setuid(uid_t uid);
int seteuid(uid_t euid);
int setgid(gid_t gid);
int setegid(gid_t egid);

char* getlogin(void);
int getlogin_r(char *buf, size_t bufsz);
char* ctermid(char *buf);

long int pathconf(const char *path, int name);
long int fpathconf(int fildes, int name);
long int sysconf(int name);
size_t confstr(int name, char *buf, size_t bufsz);

int setreuid(uid_t ruid, uid_t euid);
int setregid(gid_t rgid, gid_t egid);
int lockf(int fildes, int op, off_t length);

int nice(int incr);
void sync(void);
pid_t setpgrp(void);
void swab(const void* __restrict from, void* __restrict to, ssize_t n);

int brk(void *addr);
void* sbrk(intptr_t incr);

int vhangup(void);
int chroot(const char *path);
int getpagesize(void);
int getdtablesize(void);

int gethostname(char *buf, size_t bufsz);
int sethostname(const char *name, size_t len);
int getdomainname(char *buf, size_t bufsz);
int setdomainname(const char *name, size_t len);
int daemon(int nochdir, int noclose);

char* getusershell(void);
void setusershell(void);
void endusershell(void);

int acct(const char *path);
int getentropy(void *buffer, size_t bufsz);

#endif