root/user/include/unistd.h

INCLUDED FROM

   1 /*
   2  * Copyright (c) 2000, 2001, 2002, 2003, 2004, 2005, 2008, 2009
   3  *      The President and Fellows of Harvard College.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE UNIVERSITY AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE UNIVERSITY OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  */
  30 #ifndef _UNISTD_H_
  31 #define _UNISTD_H_
  33 #include <sys/types.h>
  35 /*
  36  * Get the various constants (flags, codes, etc.) for calls from
  37  * kernel includes. This way user-level code doesn't need to know
  38  * about the kern/ headers.
  39  */
  40 #include <kern/fcntl.h>
  41 #include <kern/ioctl.h>
  42 #include <kern/reboot.h>
  43 #include <kern/seek.h>
  44 #include <kern/time.h>
  45 #include <kern/unistd.h>
  46 #include <kern/wait.h>
  49 /*
  50  * Prototypes for OS/161 system calls.
  51  *
  52  * Note that the following system calls are prototyped in other
  53  * header files, as follows:
  54  *
  55  *     stat:     sys/stat.h
  56  *     fstat:    sys/stat.h
  57  *     lstat:    sys/stat.h
  58  *     mkdir:    sys/stat.h
  59  *
  60  * If this were standard Unix, more prototypes would go in other
  61  * header files as well, as follows:
  62  * 
  63  *     waitpid:  sys/wait.h
  64  *     open:     fcntl.h or sys/fcntl.h
  65  *     reboot:   sys/reboot.h
  66  *     ioctl:    sys/ioctl.h
  67  *     remove:   stdio.h
  68  *     rename:   stdio.h
  69  *     time:     time.h
  70  *
  71  * Also note that the prototypes for open() and mkdir() contain, for
  72  * compatibility with Unix, an extra argument that is not meaningful
  73  * in OS/161. This is the "mode" (file permissions) for a newly created
  74  * object. (With open, if no file is created, this is ignored, and the
  75  * call prototype is gimmicked so it doesn't have to be passed either.)
  76  * 
  77  * You should ignore these arguments in the OS/161 kernel unless you're
  78  * implementing security and file permissions. 
  79  *
  80  * If you are implementing security and file permissions and using a 
  81  * model different from Unix so that you need different arguments to
  82  * these calls, you may make appropriate changes, or define new syscalls
  83  * with different names and take the old ones out, or whatever. 
  84  *
  85  * As a general rule of thumb, however, while you can make as many new
  86  * syscalls of your own as you like, you shouldn't change the
  87  * definitions of the ones that are already here. They've been written
  88  * to be pretty much compatible with Unix, and the teaching staff has
  89  * test code that expects them to behave in particular ways.
  90  *
  91  * Of course, if you want to redesign the user/kernel API and make a
  92  * lot of work for yourself, feel free, just contact the teaching
  93  * staff beforehand. :-)
  94  *
  95  * The categories (required/recommended/optional) are guesses - check
  96  * the text of the various assignments for an authoritative list.
  97  */
 100 /*
 101  * NOTE NOTE NOTE NOTE NOTE
 102  *
 103  * This file is *not* shared with the kernel, even though in a sense
 104  * the kernel needs to know about these prototypes. This is because,
 105  * due to error handling concerns, the in-kernel versions of these
 106  * functions will usually have slightly different signatures.
 107  */
 110 #ifdef __GNUC__
 111 /* GCC gets into a snit if _exit isn't declared to not return */
 112 #define __DEAD __attribute__((__noreturn__))
 113 #else
 114 #define __DEAD
 115 #endif
 117 /* Required. */
__DEAD void _exit(int code);
 119 int execv(const char *prog, char *const *args);
pid_t fork(void);
 121 int waitpid(pid_t pid, int *returncode, int flags);
 122 /* 
 123  * Open actually takes either two or three args: the optional third
 124  * arg is the file mode used for creation. Unless you're implementing
 125  * security and permissions, you can ignore it.
 126  */
 127 int open(const char *filename, int flags, ...);
 128 int read(int filehandle, void *buf, size_t size);
 129 int write(int filehandle, const void *buf, size_t size);
 130 int close(int filehandle);
 131 int reboot(int code);
 132 int sync(void);
 133 /* mkdir - see sys/stat.h */
 134 int rmdir(const char *dirname);
 136 /* Recommended. */
 137 int getpid(void);
 138 int ioctl(int filehandle, int code, void *buf);
off_t lseek(int filehandle, off_t pos, int code);
 140 int fsync(int filehandle);
 141 int ftruncate(int filehandle, off_t size);
 142 int remove(const char *filename);
 143 int rename(const char *oldfile, const char *newfile);
 144 int link(const char *oldfile, const char *newfile);
 145 /* fstat - see sys/stat.h */
 146 int chdir(const char *path);
 148 /* Optional. */
 149 void *sbrk(int change);
 150 int getdirentry(int filehandle, char *buf, size_t buflen);
 151 int symlink(const char *target, const char *linkname);
 152 int readlink(const char *path, char *buf, size_t buflen);
 153 int dup2(int filehandle, int newhandle);
 154 int pipe(int filehandles[2]);
time_t __time(time_t *seconds, unsigned long *nanoseconds);
 156 int __getcwd(char *buf, size_t buflen);
 157 /* stat - see sys/stat.h */
 158 /* lstat - see sys/stat.h */
 160 /*
 161  * These are not themselves system calls, but wrapper routines in libc.
 162  */
 164 char *getcwd(char *buf, size_t buflen);         /* calls __getcwd */
time_t time(time_t *seconds);                   /* calls __time */
 167 #endif /* _UNISTD_H_ */