files.c

Quake 2 Source code for students by Theerthan You can also download from idsoftwares.com

Takes an explicit (not game tree related) path to a pak file.

Loads the header and directory, adding the files at the beginning
of the list so they override previous pack files.
=================
*/
pack_t *FS_LoadPackFile (char *packfile)
{
	dpackheader_t	header;
	int				i;
	packfile_t		*newfiles;
	int				numpackfiles;
	pack_t			*pack;
	FILE			*packhandle;
	dpackfile_t		info[MAX_FILES_IN_PACK];
	unsigned		checksum;

	packhandle = fopen(packfile, "rb");
	if (!packhandle)
		return NULL;

	fread (&header, 1, sizeof(header), packhandle);
	if (LittleLong(header.ident) != IDPAKHEADER)
		Com_Error (ERR_FATAL, "%s is not a packfile", packfile);
	header.dirofs = LittleLong (header.dirofs);
	header.dirlen = LittleLong (header.dirlen);

	numpackfiles = header.dirlen / sizeof(dpackfile_t);

	if (numpackfiles > MAX_FILES_IN_PACK)
		Com_Error (ERR_FATAL, "%s has %i files", packfile, numpackfiles);

	newfiles = Z_Malloc (numpackfiles * sizeof(packfile_t));

	fseek (packhandle, header.dirofs, SEEK_SET);
	fread (info, 1, header.dirlen, packhandle);

// crc the directory to check for modifications
	checksum = Com_BlockChecksum ((void *)info, header.dirlen);

#ifdef NO_ADDONS
	if (checksum != PAK0_CHECKSUM)
		return NULL;
#endif
// parse the directory
	for (i=0 ; i<numpackfiles ; i++)
	{
		strcpy (newfiles[i].name, info[i].name);
		newfiles[i].filepos = LittleLong(info[i].filepos);
		newfiles[i].filelen = LittleLong(info[i].filelen);
	}

	pack = Z_Malloc (sizeof (pack_t));
	strcpy (pack->filename, packfile);
	pack->handle = packhandle;
	pack->numfiles = numpackfiles;
	pack->files = newfiles;
	
	Com_Printf ("Added packfile %s (%i files)\n", packfile, numpackfiles);
	return pack;
}


/*
================
FS_AddGameDirectory

Sets fs_gamedir, adds the directory to the head of the path,
then loads and adds pak1.pak pak2.pak ... 
================
*/
void FS_AddGameDirectory (char *dir)
{
	int				i;
	searchpath_t	*search;
	pack_t			*pak;
	char			pakfile[MAX_OSPATH];

	strcpy (fs_gamedir, dir);

	//
	// add the directory to the search path
	//
	search = Z_Malloc (sizeof(searchpath_t));
	strcpy (search->filename, dir);
	search->next = fs_searchpaths;
	fs_searchpaths = search;

	//
	// add any pak files in the format pak0.pak pak1.pak, ...
	//
	for (i=0; i<10; i++)
	{
		Com_sprintf (pakfile, sizeof(pakfile), "%s/pak%i.pak", dir, i);
		pak = FS_LoadPackFile (pakfile);
		if (!pak)
			continue;
		search = Z_Malloc (sizeof(searchpath_t));
		search->pack = pak;
		search->next = fs_searchpaths;
		fs_searchpaths = search;		
	}


}

/*
============
FS_Gamedir

Called to find where to write a file (demos, savegames, etc)
============
*/
char *FS_Gamedir (void)
{
	if (*fs_gamedir)
		return fs_gamedir;
	else
		return BASEDIRNAME;
}

/*
=============
FS_ExecAutoexec
=============
*/
void FS_ExecAutoexec (void)
{
	char *dir;
	char name [MAX_QPATH];

	dir = Cvar_VariableString("gamedir");
	if (*dir)
		Com_sprintf(name, sizeof(name), "%s/%s/autoexec.cfg", fs_basedir->string, dir); 
	else
		Com_sprintf(name, sizeof(name), "%s/%s/autoexec.cfg", fs_basedir->string, BASEDIRNAME); 
	if (Sys_FindFirst(name, 0, SFF_SUBDIR | SFF_HIDDEN | SFF_SYSTEM))
		Cbuf_AddText ("exec autoexec.cfg\n");
	Sys_FindClose();
}


/*
================
FS_SetGamedir

Sets the gamedir and path to a different directory.
================
*/
void FS_SetGamedir (char *dir)
{
	searchpath_t	*next;

	if (strstr(dir, "..") || strstr(dir, "/")
		|| strstr(dir, "\\") || strstr(dir, ":") )
	{
		Com_Printf ("Gamedir should be a single filename, not a path\n");
		return;
	}

	//
	// free up any current game dir info
	//
	while (fs_searchpaths != fs_base_searchpaths)
	{
		if (fs_searchpaths->pack)
		{
			fclose (fs_searchpaths->pack->handle);
			Z_Free (fs_searchpaths->pack->files);
			Z_Free (fs_searchpaths->pack);
		}
		next = fs_searchpaths->next;
		Z_Free (fs_searchpaths);
		fs_searchpaths = next;
	}

	//
	// flush all data, so it will be forced to reload
	//
	if (dedicated && !dedicated->value)
		Cbuf_AddText ("vid_restart\nsnd_restart\n");

	Com_sprintf (fs_gamedir, sizeof(fs_gamedir), "%s/%s", fs_basedir->string, dir);

	if (!strcmp(dir,BASEDIRNAME) || (*dir == 0))
	{
		Cvar_FullSet ("gamedir", "", CVAR_SERVERINFO|CVAR_NOSET);
		Cvar_FullSet ("game", "", CVAR_LATCH|CVAR_SERVERINFO);
	}
	else
	{
		Cvar_FullSet ("gamedir", dir, CVAR_SERVERINFO|CVAR_NOSET);
		if (fs_cddir->string[0])
			FS_AddGameDirectory (va("%s/%s", fs_cddir->string, dir) );
		FS_AddGameDirectory (va("%s/%s", fs_basedir->string, dir) );
	}
}


/*
================
FS_Link_f

Creates a filelink_t
================
*/
void FS_Link_f (void)
{
	filelink_t	*l, **prev;

	if (Cmd_Argc() != 3)
	{
		Com_Printf ("USAGE: link <from> <to>\n");
		return;
	}

	// see if the link already exists
	prev = &fs_links;
	for (l=fs_links ; l ; l=l->next)
	{
		if (!strcmp (l->from, Cmd_Argv(1)))
		{
			Z_Free (l->to);
			if (!strlen(Cmd_Argv(2)))
			{	// delete it
				*prev = l->next;
				Z_Free (l->from);
				Z_Free (l);
				return;
			}
			l->to = CopyString (Cmd_Argv(2));
			return;
		}
		prev = &l->next;
	}

	// create a new link
	l = Z_Malloc(sizeof(*l));
	l->next = fs_links;
	fs_links = l;
	l->from = CopyString(Cmd_Argv(1));
	l->fromlength = strlen(l->from);
	l->to = CopyString(Cmd_Argv(2));
}

/*
** FS_ListFiles
*/
char **FS_ListFiles( char *findname, int *numfiles, unsigned musthave, unsigned canthave )
{
	char *s;
	int nfiles = 0;
	char **list = 0;

	s = Sys_FindFirst( findname, musthave, canthave );
	while ( s )
	{
		if ( s[strlen(s)-1] != '.' )
			nfiles++;
		s = Sys_FindNext( musthave, canthave );
	}
	Sys_FindClose ();

	if ( !nfiles )
		return NULL;

	nfiles++; // add space for a guard
	*numfiles = nfiles;

	list = malloc( sizeof( char * ) * nfiles );
	memset( list, 0, sizeof( char * ) * nfiles );

	s = Sys_FindFirst( findname, musthave, canthave );
	nfiles = 0;
	while ( s )
	{
		if ( s[strlen(s)-1] != '.' )
		{
			list[nfiles] = strdup( s );
#ifdef _WIN32
			strlwr( list[nfiles] );
#endif
			nfiles++;
		}
		s = Sys_FindNext( musthave, canthave );
	}
	Sys_FindClose ();

	return list;
}

/*
** FS_Dir_f
*/
void FS_Dir_f( void )
{
	char	*path = NULL;
	char	findname[1024];
	char	wildcard[1024] = "*.*";
	char	**dirnames;
	int		ndirs;

	if ( Cmd_Argc() != 1 )
	{
		strcpy( wildcard, Cmd_Argv( 1 ) );
	}

	while ( ( path = FS_NextPath( path ) ) != NULL )
	{
		char *tmp = findname;

		Com_sprintf( findname, sizeof(findname), "%s/%s", path, wildcard );

		while ( *tmp != 0 )
		{
			if ( *tmp == '\\' ) 
				*tmp = '/';
			tmp++;
		}
		Com_Printf( "Directory of %s\n", findname );
		Com_Printf( "----\n" );

		if ( ( dirnames = FS_ListFiles( findname, &ndirs, 0, 0 ) ) != 0 )
		{
			int i;

			for ( i = 0; i < ndirs-1; i++ )
			{
				if ( strrchr( dirnames[i], '/' ) )
					Com_Printf( "%s\n", strrchr( dirnames[i], '/' ) + 1 );
				else
					Com_Printf( "%s\n", dirnames[i] );

				free( dirnames[i] );
			}
			free( dirnames );
		}
		Com_Printf( "\n" );
	};
}

/*
============
FS_Path_f

============
*/
void FS_Path_f (void)
{
	searchpath_t	*s;
	filelink_t		*l;

	Com_Printf ("Current search path:\n");
	for (s=fs_searchpaths ; s ; s=s->next)
	{
		if (s == fs_base_searchpaths)
			Com_Printf ("----------\n");
		if (s->pack)
			Com_Printf ("%s (%i files)\n", s->pack->filename, s->pack->numfiles);
		else
			Com_Printf ("%s\n", s->filename);
	}

	Com_Printf ("\nLinks:\n");
	for (l=fs_links ; l ; l=l->next)
		Com_Printf ("%s : %s\n", l->from, l->to);
}

/*
================
FS_NextPath

Allows enumerating all of the directories in the search path
================
*/
char *FS_NextPath (char *prevpath)
{
	searchpath_t	*s;
	char			*prev;

	if (!prevpath)
		return fs_gamedir;

	prev = fs_gamedir;
	for (s=fs_searchpaths ; s ; s=s->next)
	{
		if (s->pack)
			continue;
		if (prevpath == prev)
			return s->filename;
		prev = s->filename;
	}

	return NULL;
}


/*
================
FS_InitFilesystem
================
*/
void FS_InitFilesystem (void)
{
	Cmd_AddCommand ("path", FS_Path_f);
	Cmd_AddCommand ("link", FS_Link_f);
	Cmd_AddCommand ("dir", FS_Dir_f );

	//
	// basedir <path>
	// allows the game to run from outside the data tree
	//
	fs_basedir = Cvar_Get ("basedir", ".", CVAR_NOSET);

	//
	// cddir <path>
	// Logically concatenates the cddir after the basedir for 
	// allows the game to run from outside the data tree
	//
	fs_cddir = Cvar_Get ("cddir", "", CVAR_NOSET);
	if (fs_cddir->string[0])
		FS_AddGameDirectory (va("%s/"BASEDIRNAME, fs_cddir->string) );

	//
	// start up with baseq2 by default
	//
	FS_AddGameDirectory (va("%s/"BASEDIRNAME, fs_basedir->string) );

	// any set gamedirs will be freed up to here
	fs_base_searchpaths = fs_searchpaths;

	// check for game override
	fs_gamedirvar = Cvar_Get ("game", "", CVAR_LATCH|CVAR_SERVERINFO);
	if (fs_gamedirvar->string[0])
		FS_SetGamedir (fs_gamedirvar->string);
}