Add possibility to backup the savefile before starting nethack.

git-svn-id: svn://katsu.triplehelix.org/dgamelaunch/trunk@282 db0b04b0-f4d1-0310-9a6d-de3e77497b0e

Changelog

@@ -1,6 +1,9 @@
 1.4.5 (????/??/??)
 	* Reset offset if necessary to show at least one game  to avoid things
 	  like "(15-14 of 14)".
+	* Backup the savefile before starting nethack to help prevent more
+	  lost games. Note this must be explicitly configured in the
+	  configuration file.
 
 1.4.4 (2004/03/07)
 	* Show total number of games in progress below the list, useful if

config.l

@@ -65,6 +65,7 @@ COMMENT		^#.*
 "rc_template"	{ return TYPE_PATH_CANNED; }
 "passwd"	{ return TYPE_PATH_PASSWD; }
 "lockfile"	{ return TYPE_PATH_LOCKFILE; }
+"savefilefmt"	{ return TYPE_PATH_SAVEFILEFMT; }
 
 \n		{ line++; col = 0; }
 

config.y

@@ -28,7 +28,8 @@ static const char* lookup_token (int t);
 %token TYPE_SUSER TYPE_SGROUP TYPE_SGID TYPE_SUID TYPE_MAX
 %token TYPE_PATH_NETHACK TYPE_PATH_DGLDIR TYPE_PATH_SPOOL
 %token TYPE_PATH_BANNER TYPE_PATH_CANNED TYPE_PATH_CHROOT
-%token TYPE_PATH_PASSWD TYPE_PATH_LOCKFILE TYPE_MALSTRING
+%token TYPE_PATH_PASSWD TYPE_PATH_LOCKFILE TYPE_PATH_SAVEFILEFMT
+%token TYPE_MALSTRING
 %token <s> TYPE_VALUE
 %token <i> TYPE_NUMBER
 %type  <kt> KeyType
@@ -147,6 +148,11 @@ KeyPair: KeyType '=' TYPE_VALUE {
       myconfig->passwd = strdup($3);
       break;
 
+    case TYPE_PATH_SAVEFILEFMT:
+      if (myconfig->savefilefmt) free(myconfig->savefilefmt);
+      myconfig->savefilefmt = strdup($3);
+      break;
+
     default:
       fprintf(stderr, "%s:%d: token %s does not take a string, bailing out\n",
         config, line, lookup_token($1));
@@ -215,6 +221,7 @@ KeyType : TYPE_SUSER	{ $$ = TYPE_SUSER; }
 	| TYPE_PATH_CANNED	{ $$ = TYPE_PATH_CANNED; }
 	| TYPE_PATH_PASSWD	{ $$ = TYPE_PATH_PASSWD; }
 	| TYPE_PATH_LOCKFILE	{ $$ = TYPE_PATH_LOCKFILE; }
+	| TYPE_PATH_SAVEFILEFMT	{ $$ = TYPE_PATH_SAVEFILEFMT; }
 	;
 
 %%

dgamelaunch.8

@@ -52,7 +52,7 @@ login(1)
 Ignored; solely for compatibility with
 .B
 login(1)
-.SH CRASH RECOVERY
+.SH "CRASH RECOVERY"
 .PP
 If a user somehow disconnects in an unclean way,
 .I
@@ -69,7 +69,17 @@ nethack does not shut down within 10 seconds,
 .I
 dgamelaunch
 will ask the user for permission to send it the SIGTERM signal, which causes
-nethack to terminate quickly.
+nethack to terminate quickly (without leaving a savefile usually).
+.PP
+In some cases (e.g. at "Restoring save file...--More--") nethack doesn't leave
+a savefile if sent SIGHUP. To avoid loss of games,
+.I
+dgamelaunch
+can backup the savefile. A human must then restore the backup if necessary.
+This must be configured with the
+.B
+savefilefmt
+option in the configuration file.
 .SH AUTHORS
 .PP
 M. Drew Streib wrote the original version.

dgamelaunch.c

@@ -1294,6 +1294,103 @@ writefile (int requirenew)
 /* ************************************************************* */
 /* ************************************************************* */
 
+/*
+ * Backup the savefile, if configured.
+ * Returns non-zero if successful, otherwise an error message has been
+ * given already.
+ */
+int
+backup_savefile (void)
+{
+  char buf[1024];
+  char *f, *p, *end;
+  int ispercent = 0, n;
+  int in, out;
+
+  f = myconfig->savefilefmt;
+
+  if (*f == '\0')
+    return 1;
+  if (me == NULL)
+    graceful_exit (147);
+
+  p = buf;
+  end = buf + sizeof(buf) - 10; /* make sure we can add .bak */
+  while (*f)
+    {
+      if (ispercent)
+        {
+          switch (*f)
+  	  {
+  	    case 'u':
+  	      snprintf (p, end + 1 - p, "%d", myconfig->shed_uid);
+  	      while (*p != '\0')
+  	        p++;
+  	      break;
+  	    case 'n':
+  	      snprintf (p, end + 1 - p, "%s", me->username);
+  	      while (*p != '\0')
+  	        p++;
+  	      break;
+  	    default:
+  	      *p = *f;
+  	      if (p < end)
+  	        p++;
+  	  }
+	  ispercent = 0;
+	}
+      else
+        {
+	  if (*f == '%')
+	    ispercent = 1;
+	  else
+	    {
+	      *p = *f;
+	      if (p < end)
+	        p++;
+	    }
+	}
+      f++;
+    }
+  *p = '\0';
+
+  /*fprintf(stderr, "***\n[SAVEFILE=%s]\n***\n", buf);
+  sleep(3);*/
+  in = open (buf, O_RDONLY);
+  if (in == -1)
+    {
+      if (errno == ENOENT)
+        return 1; /* Nothing to back up */
+      else
+        {
+          fprintf (stderr, "Cannot open savefile '%s'\n", buf);
+	  perror ("for input");
+          return 0;
+        }
+    }
+  strcpy (p, ".bak");
+  out = open (buf, O_WRONLY | O_CREAT | O_TRUNC, 0666);
+  if (out == -1)
+    {
+      close (in);
+      fprintf (stderr, "Cannot open backup savefile '%s'\n", buf);
+      perror ("for output");
+      return 0;
+    }
+
+  while ((n = read (in, buf, sizeof(buf))) > 0)
+    {
+      n = write (out, buf, n);
+      if (n < 0)
+        break;
+    }
+  close (out);
+  close (in);
+  if (n < 0)
+    perror ("I/O error while backing up savefile");
+  return n >= 0;
+}
+
 /* TODO: Some of the messages here (sorry no nethack for you!) are nethack specific
  * as may be some code... don't think so though. Globalize it. */ 
 int
@@ -1561,6 +1658,9 @@ main (int argc, char** argv)
   endwin ();
   signal(SIGWINCH, SIG_DFL);
 
+  if (!backup_savefile ())
+    graceful_exit (5);
+
   /* environment */
   snprintf (atrcfilename, 81, "@%s", rcfilename);
 

dgamelaunch.conf

@@ -49,3 +49,9 @@ rc_template = "/dgl-default-rcfile"
 
 passwd = "/dgl-login"
 lockfile = "/dgl-lock"
+
+# From inside the jail, the path to the savefile. %u is replaced by the
+# decimal representation of shed_uid, %n is replaced by the player's
+# user name. Before starting the game, this file is copied to its name
+# with ".bak" appended. Set to an empty string to disable this copying.
+savefilefmt = "/var/games/nethack/save/%u%n.gz"

dgamelaunch.h

@@ -57,6 +57,7 @@ struct dg_config
   uid_t shed_uid;
   gid_t shed_gid;
   unsigned long max;
+  char* savefilefmt;
 };
 
 /* Global variables */

dgl-common.c

@@ -29,7 +29,8 @@ struct dg_config defconfig = {
   /* shed_group = */ "games",
   /* shed_uid = */ 5,
   /* shed_gid = */ 60, /* games:games in Debian */
-  /* max = */ 64000 
+  /* max = */ 64000,
+  /* savefilefmt = */ "" /* don't do this by default */
 };
 
 char* config = NULL;
@@ -237,4 +238,5 @@ create_config ()
   if (!myconfig->spool) myconfig->spool = defconfig.spool;
   if (!myconfig->passwd) myconfig->passwd = defconfig.passwd;
   if (!myconfig->lockfile) myconfig->lockfile = defconfig.lockfile;
+  if (!myconfig->savefilefmt) myconfig->savefilefmt = defconfig.savefilefmt;
 }