Initial version.

diff --git a/lib-src/update-game-score.c b/lib-src/update-game-score.c
new file mode 100644 (file)
index 0000000..9cf4c43
--- /dev/null
+++ b/lib-src/update-game-score.c
@@ -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