mirror of
https://git.savannah.gnu.org/git/emacs.git
synced 2024-12-30 11:09:23 +00:00
Initial version.
This commit is contained in:
Colin Walters
parent
5162c705f8
commit
2f1de3dd26
373
lib-src/update-game-score.c
Normal file
373
lib-src/update-game-score.c
Normal file
@ -0,0 +1,373 @@
|
||||
/* update-game-score.c --- Update a score file
|
||||
Copyright (C) 2002 Free Software Foundation, Inc.
|
||||
|
||||
This file is part of GNU Emacs.
|
||||
|
||||
GNU Emacs is free software; you can redistribute it and/or modify
|
||||
it under the terms of the GNU General Public License as published by
|
||||
the Free Software Foundation; either version 2, or (at your option)
|
||||
any later version.
|
||||
|
||||
GNU Emacs is distributed in the hope that it will be useful,
|
||||
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||||
GNU General Public License for more details.
|
||||
|
||||
You should have received a copy of the GNU General Public License
|
||||
along with GNU Emacs; see the file COPYING. If not, write to
|
||||
the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
|
||||
Boston, MA 02111-1307, USA. */
|
||||
|
||||
/* This program is allows a game to securely and atomically update a
|
||||
score file. It should be installed setgid, owned by an appropriate
|
||||
group like `games'.
|
||||
|
||||
Created 2002/03/22, by Colin Walters <walters@debian.org>
|
||||
*/
|
||||
|
||||
#define _GNU_SOURCE
|
||||
|
||||
#include <unistd.h>
|
||||
#include <errno.h>
|
||||
#include <string.h>
|
||||
#include <stdlib.h>
|
||||
#include <stdio.h>
|
||||
#include <time.h>
|
||||
#include <ctype.h>
|
||||
#include <fcntl.h>
|
||||
#include <sys/stat.h>
|
||||
// #include "config.h"
|
||||
|
||||
#define MAX_ATTEMPTS 5
|
||||
#define SCORE_FILE_PREFIX "/var/games/emacs/"
|
||||
|
||||
int
|
||||
usage(int err)
|
||||
{
|
||||
fprintf(stdout, "Usage: update-game-score [-m MAX ] [ -r ] game/scorefile SCORE DATA\n");
|
||||
fprintf(stdout, " update-game-score -h\n");
|
||||
fprintf(stdout, " -h\t\tDisplay this help.\n");
|
||||
fprintf(stdout, " -m MAX\t\tLimit the maximum number of scores to MAX.\n");
|
||||
fprintf(stdout, " -r\t\tSort the scores in increasing order.\n");
|
||||
exit(err);
|
||||
}
|
||||
|
||||
int
|
||||
lock_file(const char *filename, void **state);
|
||||
int
|
||||
unlock_file(const char *filename, void *state);
|
||||
|
||||
struct score_entry
|
||||
{
|
||||
long score;
|
||||
char *data;
|
||||
};
|
||||
|
||||
int
|
||||
read_scores(const char *filename, struct score_entry **scores,
|
||||
int *count);
|
||||
int
|
||||
push_score(struct score_entry **scores, int *count,
|
||||
int newscore, char *newdata);
|
||||
void
|
||||
sort_scores(struct score_entry *scores, int count, int reverse);
|
||||
int
|
||||
write_scores(const char *filename, const struct score_entry *scores,
|
||||
int count);
|
||||
|
||||
int
|
||||
main(int argc, char **argv)
|
||||
{
|
||||
int c;
|
||||
void *lockstate;
|
||||
char *scorefile;
|
||||
struct stat buf;
|
||||
struct score_entry *scores;
|
||||
int newscore, scorecount, reverse = 0, max = -1;
|
||||
char *newdata;
|
||||
|
||||
srand(time(0));
|
||||
|
||||
while ((c = getopt(argc, argv, "hrm:")) != -1)
|
||||
switch (c)
|
||||
{
|
||||
case 'h':
|
||||
usage(0);
|
||||
break;
|
||||
case 'r':
|
||||
reverse = 1;
|
||||
break;
|
||||
case 'm':
|
||||
max = atoi(optarg);
|
||||
break;
|
||||
default:
|
||||
usage(1);
|
||||
}
|
||||
|
||||
if (optind+3 != argc)
|
||||
usage(1);
|
||||
scorefile = malloc(strlen(SCORE_FILE_PREFIX) + strlen(argv[optind]) + 20);
|
||||
if (!scorefile)
|
||||
{
|
||||
fprintf(stderr, "Couldn't create score file name: %s\n",
|
||||
strerror(errno));
|
||||
goto fail;
|
||||
}
|
||||
strcpy(scorefile, SCORE_FILE_PREFIX);
|
||||
strcat(scorefile, argv[optind]);
|
||||
newscore = atoi(argv[optind+1]);
|
||||
newdata = argv[optind+2];
|
||||
|
||||
if (stat(scorefile, &buf) < 0)
|
||||
{
|
||||
fprintf(stderr, "Failed to access scores file \"%s\": %s\n",
|
||||
scorefile, strerror(errno));
|
||||
goto fail;
|
||||
}
|
||||
if (lock_file(scorefile, &lockstate) < 0)
|
||||
{
|
||||
fprintf(stderr, "Failed to lock scores file \"%s\": %s\n",
|
||||
scorefile, strerror(errno));
|
||||
goto fail;
|
||||
}
|
||||
if (read_scores(scorefile, &scores, &scorecount) < 0)
|
||||
{
|
||||
fprintf(stderr, "Failed to read scores file \"%s\": %s\n",
|
||||
scorefile, strerror(errno));
|
||||
goto fail_unlock;
|
||||
}
|
||||
push_score(&scores, &scorecount, newscore, newdata);
|
||||
sort_scores(scores, scorecount, reverse);
|
||||
if (write_scores(scorefile, scores, scorecount) < 0)
|
||||
{
|
||||
fprintf(stderr, "Failed to write scores file \"%s\": %s\n",
|
||||
scorefile, strerror(errno));
|
||||
goto fail_unlock;
|
||||
}
|
||||
unlock_file(scorefile, lockstate);
|
||||
exit(0);
|
||||
fail_unlock:
|
||||
unlock_file(scorefile, lockstate);
|
||||
fail:
|
||||
exit(1);
|
||||
}
|
||||
|
||||
int
|
||||
read_score(FILE *f, struct score_entry *score)
|
||||
{
|
||||
int c;
|
||||
if (feof(f))
|
||||
return 1;
|
||||
while ((c = getc(f)) != EOF
|
||||
&& isdigit(c)) {
|
||||
score->score *= 10;
|
||||
score->score += (c-48);
|
||||
}
|
||||
#ifdef HAVE_GETLINE
|
||||
score->data = NULL;
|
||||
errno = ESUCCES;
|
||||
{
|
||||
int len;
|
||||
if (getline(&score->data, &len, f) < 0)
|
||||
return -1;
|
||||
}
|
||||
#else
|
||||
/* We should probably just copy the getline code into here from
|
||||
glibc, instead of this halfassed solution. */
|
||||
score->data = malloc(122);
|
||||
score->data[0] = '\0';
|
||||
if (!fgets(score->data, 120, f))
|
||||
return -1;
|
||||
#endif
|
||||
/* Trim the newline */
|
||||
score->data[strlen(score->data)-1] = '\0';
|
||||
return 0;
|
||||
}
|
||||
|
||||
int
|
||||
read_scores(const char *filename, struct score_entry **scores,
|
||||
int *count)
|
||||
{
|
||||
int readval, scorecount, cursize;
|
||||
struct score_entry *ret;
|
||||
FILE *f = fopen(filename, "r");
|
||||
if (!f)
|
||||
return -1;
|
||||
scorecount = 0;
|
||||
cursize = 16;
|
||||
ret = malloc(sizeof(struct score_entry) * cursize);
|
||||
if (!ret)
|
||||
return -1;
|
||||
while ((readval = read_score(f, &ret[scorecount])) == 0)
|
||||
{
|
||||
/* We encoutered an error */
|
||||
if (readval < 0)
|
||||
return -1;
|
||||
scorecount++;
|
||||
if (scorecount >= cursize)
|
||||
{
|
||||
ret = realloc(ret, cursize *= 2);
|
||||
if (!ret)
|
||||
return -1;
|
||||
}
|
||||
}
|
||||
*count = scorecount;
|
||||
*scores = ret;
|
||||
return 0;
|
||||
}
|
||||
|
||||
int
|
||||
score_compare(const void *a, const void *b)
|
||||
{
|
||||
const struct score_entry *sa = (const struct score_entry *) a;
|
||||
const struct score_entry *sb = (const struct score_entry *) b;
|
||||
return (sb->score > sa->score) - (sb->score < sa->score);
|
||||
}
|
||||
|
||||
int
|
||||
score_compare_reverse(const void *a, const void *b)
|
||||
{
|
||||
const struct score_entry *sa = (const struct score_entry *) a;
|
||||
const struct score_entry *sb = (const struct score_entry *) b;
|
||||
return (sa->score > sb->score) - (sa->score < sb->score);
|
||||
}
|
||||
|
||||
int
|
||||
push_score(struct score_entry **scores, int *count,
|
||||
int newscore, char *newdata)
|
||||
{
|
||||
struct score_entry *newscores = realloc(*scores,
|
||||
sizeof(struct score_entry) * ((*count) + 1));
|
||||
if (!newscores)
|
||||
return -1;
|
||||
newscores[*count].score = newscore;
|
||||
newscores[*count].data = newdata;
|
||||
(*count) += 1;
|
||||
*scores = newscores;
|
||||
return 0;
|
||||
}
|
||||
|
||||
void
|
||||
sort_scores(struct score_entry *scores, int count, int reverse)
|
||||
{
|
||||
qsort(scores, count, sizeof(struct score_entry),
|
||||
reverse ? score_compare_reverse : score_compare);
|
||||
}
|
||||
|
||||
int
|
||||
write_scores(const char *filename, const struct score_entry *scores,
|
||||
int count)
|
||||
{
|
||||
FILE *f;
|
||||
int i;
|
||||
char *tempfile = malloc(strlen(filename) + strlen(".tempXXXXXX") + 1);
|
||||
if (!tempfile)
|
||||
return -1;
|
||||
strcpy(tempfile, filename);
|
||||
strcat(tempfile, ".tempXXXXXX");
|
||||
if (mkstemp(tempfile) < 0
|
||||
|| !(f = fopen(tempfile, "w")))
|
||||
return -1;
|
||||
for (i = 0; i < count; i++)
|
||||
if (fprintf(f, "%ld %s\n", scores[i].score, scores[i].data) < 0)
|
||||
return -1;
|
||||
fclose(f);
|
||||
rename(tempfile, filename);
|
||||
return 0;
|
||||
}
|
||||
|
||||
#if 0
|
||||
int
|
||||
lock_file(const char *filename, void **state)
|
||||
{
|
||||
struct flock lock;
|
||||
int *istate;
|
||||
int fd, attempts = 0, ret = 0;
|
||||
lock.l_type = F_WRLCK;
|
||||
lock.l_whence = SEEK_SET;
|
||||
lock.l_start = 0;
|
||||
lock.l_len = 0;
|
||||
istate = malloc(sizeof(int));
|
||||
if (!istate)
|
||||
return -1;
|
||||
if ((fd = open(filename, O_RDWR, 0600)) < 0)
|
||||
return -1;
|
||||
*istate = fd;
|
||||
trylock:
|
||||
attempts++;
|
||||
if ((ret = fcntl(fd, F_GETLK, &lock)) == -1)
|
||||
{
|
||||
if (ret == EACCES || ret == EAGAIN)
|
||||
if (attempts > MAX_ATTEMPTS)
|
||||
exit(1);
|
||||
else
|
||||
{
|
||||
sleep((rand() % 3)+1);
|
||||
goto trylock;
|
||||
}
|
||||
else
|
||||
ret = 0 ;
|
||||
}
|
||||
else
|
||||
ret = 0;
|
||||
*state = istate;
|
||||
return ret;
|
||||
}
|
||||
|
||||
int
|
||||
unlock_file(const char *filename, void *state)
|
||||
{
|
||||
int fd, ret;
|
||||
fd = *((int *) state);
|
||||
free(state);
|
||||
ret = close(fd);
|
||||
return ret;
|
||||
}
|
||||
|
||||
#else
|
||||
|
||||
int
|
||||
lock_file(const char *filename, void **state)
|
||||
{
|
||||
int fd;
|
||||
int attempts = 0;
|
||||
char *lockext = ".lockfile";
|
||||
char *lockpath = malloc(strlen(filename) + strlen(lockext) + 60);
|
||||
if (!lockpath)
|
||||
return -1;
|
||||
strcpy(lockpath, filename);
|
||||
strcat(lockpath, lockext);
|
||||
*state = lockpath;
|
||||
trylock:
|
||||
attempts++;
|
||||
if ((fd = open(lockpath, O_CREAT | O_EXCL, 0600)) < 0)
|
||||
{
|
||||
if (errno == EEXIST)
|
||||
{
|
||||
/* Break the lock; we won't corrupt the file, but we might
|
||||
lose some scores. */
|
||||
if (attempts > MAX_ATTEMPTS)
|
||||
unlink(lockpath);
|
||||
else
|
||||
sleep((rand() % 2)+1);
|
||||
goto trylock;
|
||||
}
|
||||
else
|
||||
return -1;
|
||||
}
|
||||
close(fd);
|
||||
return 0;
|
||||
}
|
||||
|
||||
int
|
||||
unlock_file(const char *filename, void *state)
|
||||
{
|
||||
char *lockpath = (char *) state;
|
||||
int ret = unlink(lockpath);
|
||||
int saved_errno = errno;
|
||||
free(lockpath);
|
||||
errno = saved_errno;
|
||||
return ret;
|
||||
}
|
||||
|
||||
#endif
|
||||
Loading…
Reference in New Issue
Block a user