NetBSD-5.0.2/games/rogue/machdep.c
/* $NetBSD: machdep.c,v 1.17 2008/01/14 03:50:01 dholland Exp $ */
/*
* Copyright (c) 1988, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Timothy C. Stoehr.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
#ifndef lint
#if 0
static char sccsid[] = "@(#)machdep.c 8.1 (Berkeley) 5/31/93";
#else
__RCSID("$NetBSD: machdep.c,v 1.17 2008/01/14 03:50:01 dholland Exp $");
#endif
#endif /* not lint */
/*
* machdep.c
*
* This source herein may be modified and/or distributed by anybody who
* so desires, with the following restrictions:
* 1.) No portion of this notice shall be removed.
* 2.) Credit shall not be taken for the creation of this source.
* 3.) This code is not to be traded, sold, or used for personal
* gain or profit.
*
*/
/* Included in this file are all system dependent routines. Extensive use
* of #ifdef's will be used to compile the appropriate code on each system:
*
* UNIX: all UNIX systems.
* UNIX_BSD4_2: UNIX BSD 4.2 and later, UTEK, (4.1 BSD too?)
* UNIX_SYSV: UNIX system V
* UNIX_V7: UNIX version 7
*
* All UNIX code should be included between the single "#ifdef UNIX" at the
* top of this file, and the "#endif" at the bottom.
*
* To change a routine to include a new UNIX system, simply #ifdef the
* existing routine, as in the following example:
*
* To make a routine compatible with UNIX system 5, change the first
* function to the second:
*
* md_function()
* {
* code;
* }
*
* md_function()
* {
* #ifdef UNIX_SYSV
* sys5code;
* #else
* code;
* #endif
* }
*
* Appropriate variations of this are of course acceptible.
* The use of "#elseif" is discouraged because of non-portability.
* If the correct #define doesn't exist, "UNIX_SYSV" in this case, make it up
* and insert it in the list at the top of the file. Alter the CFLAGS
* in you Makefile appropriately.
*
*/
#ifdef UNIX
#include <sys/types.h>
#include <sys/wait.h>
#include <sys/file.h>
#include <sys/stat.h>
#include <pwd.h>
#ifdef UNIX_BSD4_2
#include <sys/time.h>
#endif
#ifdef UNIX_SYSV
#include <time.h>
#endif
#include <signal.h>
#include <stdlib.h>
#include <termios.h>
#include <unistd.h>
#include "rogue.h"
#include "pathnames.h"
/* md_slurp:
*
* This routine throws away all keyboard input that has not
* yet been read. It is used to get rid of input that the user may have
* typed-ahead.
*
* This function is not necessary, so it may be stubbed. The might cause
* message-line output to flash by because the game has continued to read
* input without waiting for the user to read the message. Not such a
* big deal.
*/
void
md_slurp(void)
{
(void)fpurge(stdin);
}
/* md_heed_signals():
*
* This routine tells the program to call particular routines when
* certain interrupts/events occur:
*
* SIGINT: call onintr() to interrupt fight with monster or long rest.
* SIGQUIT: call byebye() to check for game termination.
* SIGHUP: call error_save() to save game when terminal hangs up.
*
* On VMS, SIGINT and SIGQUIT correspond to ^C and ^Y.
*
* This routine is not strictly necessary and can be stubbed. This will
* mean that the game cannot be interrupted properly with keyboard
* input, this is not usually critical.
*/
void
md_heed_signals(void)
{
signal(SIGINT, onintr);
signal(SIGQUIT, byebye);
signal(SIGHUP, error_save);
}
/* md_ignore_signals():
*
* This routine tells the program to completely ignore the events mentioned
* in md_heed_signals() above. The event handlers will later be turned on
* by a future call to md_heed_signals(), so md_heed_signals() and
* md_ignore_signals() need to work together.
*
* This function should be implemented or the user risks interrupting
* critical sections of code, which could cause score file, or saved-game
* file, corruption.
*/
void
md_ignore_signals(void)
{
signal(SIGQUIT, SIG_IGN);
signal(SIGINT, SIG_IGN);
signal(SIGHUP, SIG_IGN);
}
/* md_get_file_id():
*
* This function returns an integer that uniquely identifies the specified
* file. It need not check for the file's existence. In UNIX, the inode
* number is used.
*
* This function is used to identify saved-game files.
*/
int
md_get_file_id(const char *fname)
{
struct stat sbuf;
if (stat(fname, &sbuf)) {
return(-1);
}
return((int)sbuf.st_ino);
}
/* md_link_count():
*
* This routine returns the number of hard links to the specified file.
*
* This function is not strictly necessary. On systems without hard links
* this routine can be stubbed by just returning 1.
*/
int
md_link_count(const char *fname)
{
struct stat sbuf;
stat(fname, &sbuf);
return((int)sbuf.st_nlink);
}
/* md_gct(): (Get Current Time)
*
* This function returns the current year, month(1-12), day(1-31), hour(0-23),
* minute(0-59), and second(0-59). This is used for identifying the time
* at which a game is saved.
*
* This function is not strictly necessary. It can be stubbed by returning
* zeros instead of the correct year, month, etc. If your operating
* system doesn't provide all of the time units requested here, then you
* can provide only those that it does, and return zeros for the others.
* If you cannot provide good time values, then users may be able to copy
* saved-game files and play them.
*/
void
md_gct(struct rogue_time *rt_buf)
{
struct tm *t;
time_t seconds;
time(&seconds);
t = localtime(&seconds);
rt_buf->year = t->tm_year;
rt_buf->month = t->tm_mon + 1;
rt_buf->day = t->tm_mday;
rt_buf->hour = t->tm_hour;
rt_buf->minute = t->tm_min;
rt_buf->second = t->tm_sec;
}
/* md_gfmt: (Get File Modification Time)
*
* This routine returns a file's date of last modification in the same format
* as md_gct() above.
*
* This function is not strictly necessary. It is used to see if saved-game
* files have been modified since they were saved. If you have stubbed the
* routine md_gct() above by returning constant values, then you may do
* exactly the same here.
* Or if md_gct() is implemented correctly, but your system does not provide
* file modification dates, you may return some date far in the past so
* that the program will never know that a saved-game file being modified.
* You may also do this if you wish to be able to restore games from
* saved-games that have been modified.
*/
void
md_gfmt(const char *fname, struct rogue_time *rt_buf)
{
struct stat sbuf;
time_t seconds;
struct tm *t;
stat(fname, &sbuf);
seconds = sbuf.st_mtime;
t = localtime(&seconds);
rt_buf->year = t->tm_year;
rt_buf->month = t->tm_mon + 1;
rt_buf->day = t->tm_mday;
rt_buf->hour = t->tm_hour;
rt_buf->minute = t->tm_min;
rt_buf->second = t->tm_sec;
}
/* md_df: (Delete File)
*
* This function deletes the specified file, and returns true (1) if the
* operation was successful. This is used to delete saved-game files
* after restoring games from them.
*
* Again, this function is not strictly necessary, and can be stubbed
* by simply returning 1. In this case, saved-game files will not be
* deleted and can be replayed.
*/
boolean
md_df(const char *fname)
{
if (unlink(fname)) {
return(0);
}
return(1);
}
/* md_gln: (Get login name)
*
* This routine returns the login name of the user. This string is
* used mainly for identifying users in score files.
*
* A dummy string may be returned if you are unable to implement this
* function, but then the score file would only have one name in it.
*/
const char *
md_gln(void)
{
struct passwd *p;
if (!(p = getpwuid(getuid())))
return NULL;
return p->pw_name;
}
/* md_sleep:
*
* This routine causes the game to pause for the specified number of
* seconds.
*
* This routine is not particularly necessary at all. It is used for
* delaying execution, which is useful to this program at some times.
*/
void
md_sleep(int nsecs)
{
(void)sleep(nsecs);
}
/* md_getenv()
*
* This routine gets certain values from the user's environment. These
* values are strings, and each string is identified by a name. The names
* of the values needed, and their use, is as follows:
*
* ROGUEOPTS
* A string containing the various game options. This need not be
* defined.
* HOME
* The user's home directory. This is only used when the user specifies
* '~' as the first character of a saved-game file. This string need
* not be defined.
* SHELL
* The user's favorite shell. If not found, "/bin/sh" is assumed.
*
* If your system does not provide a means of searching for these values,
* you will have to do it yourself. None of the values above really need
* to be defined; you can get by with simply always returning zero.
* Returning zero indicates that their is no defined value for the
* given string.
*/
char *
md_getenv(const char *name)
{
char *value;
value = getenv(name);
return(value);
}
/* md_malloc()
*
* This routine allocates, and returns a pointer to, the specified number
* of bytes. This routines absolutely MUST be implemented for your
* particular system or the program will not run at all. Return zero
* when no more memory can be allocated.
*/
void *
md_malloc(size_t n)
{
char *t;
t = malloc(n);
return(t);
}
/* md_gseed() (Get Seed)
*
* This function returns a seed for the random number generator (RNG). This
* seed causes the RNG to begin generating numbers at some point in its
* sequence. Without a random seed, the RNG will generate the same set
* of numbers, and every game will start out exactly the same way. A good
* number to use is the process id, given by getpid() on most UNIX systems.
*
* You need to find some single random integer, such as:
* process id.
* current time (minutes + seconds) returned from md_gct(), if implemented.
*
* It will not help to return "get_rand()" or "rand()" or the return value of
* any pseudo-RNG. If you don't have a random number, you can just return 1,
* but this means your games will ALWAYS start the same way, and will play
* exactly the same way given the same input.
*/
int
md_gseed(void)
{
time_t seconds;
time(&seconds);
return((int)seconds);
}
/* md_exit():
*
* This function causes the program to discontinue execution and exit.
* This function must be implemented or the program will continue to
* hang when it should quit.
*/
void
md_exit(int status)
{
exit(status);
}
/* md_lock():
*
* This function is intended to give the user exclusive access to the score
* file. It does so by flock'ing the score file. The full path name of the
* score file should be defined for any particular site in rogue.h. The
* constants _PATH_SCOREFILE defines this file name.
*
* When the parameter 'l' is non-zero (true), a lock is requested. Otherwise
* the lock is released.
*/
void
md_lock(boolean l)
{
static int fd = -1;
short tries;
if (l) {
setegid(egid);
if ((fd = open(_PATH_SCOREFILE, O_RDONLY)) < 1) {
setegid(gid);
messagef(0, "cannot lock score file");
return;
}
setegid(gid);
for (tries = 0; tries < 5; tries++)
if (!flock(fd, LOCK_EX|LOCK_NB))
return;
} else {
(void)flock(fd, LOCK_UN|LOCK_NB);
(void)close(fd);
}
}
/* md_shell():
*
* This function spawns a shell for the user to use. When this shell is
* terminated, the game continues.
*
* It is important that the game not give the shell the privileges the
* game uses to access the scores file. This version of the game runs
* with privileges low by default; only the saved gid (if setgid) or uid
* (if setuid) will be privileged, but that privilege is discarded by
* exec().
*/
void
md_shell(const char *shell)
{
int w;
pid_t pid;
pid = fork();
switch (pid) {
case -1:
break;
case 0:
execl(shell, shell, (char *)NULL);
_exit(255);
default:
waitpid(pid, &w, 0);
break;
}
}
#endif /* UNIX */