command.c

// SONIC ROBO BLAST 2
//-----------------------------------------------------------------------------
// Copyright (C) 1998-2000 by DooM Legacy Team.
// Copyright (C) 1999-2018 by Sonic Team Junior.
//
// This program is free software distributed under the
// terms of the GNU General Public License, version 2.
// See the 'LICENSE' file for more details.
//-----------------------------------------------------------------------------
/// \file  command.c
/// \brief Parse and execute commands from console input/scripts and remote server
///
///        Handles console variables, which is a simplified version
///        of commands, each consvar can have a function called when
///        it is modified.. thus it acts nearly as commands.
///
///        code shamelessly inspired by the QuakeC sources, thanks Id :)

#include "doomdef.h"
#include "doomstat.h"
#include "command.h"
#include "console.h"
#include "z_zone.h"
#include "m_menu.h"
#include "m_misc.h"
#include "m_fixed.h"
#include "m_argv.h"
#include "byteptr.h"
#include "p_saveg.h"
#include "g_game.h" // for player_names
#include "m_cond.h" // for encore mode
#include "d_netcmd.h"
#include "hu_stuff.h"
#include "p_setup.h"
#include "lua_script.h"
#include "d_netfil.h" // findfile

//========
// protos.
//========
static boolean COM_Exists(const char *com_name);
static void COM_ExecuteString(char *com_text);

static void COM_Alias_f(void);
static void COM_Echo_f(void);
static void COM_CEcho_f(void);
static void COM_CEchoFlags_f(void);
static void COM_CEchoDuration_f(void);
static void COM_Exec_f(void);
static void COM_Wait_f(void);
static void COM_Help_f(void);
static void COM_Toggle_f(void);
static void COM_Add_f(void);

static void CV_EnforceExecVersion(void);
static boolean CV_FilterVarByVersion(consvar_t *v, const char *valstr);

static boolean CV_Command(void);
consvar_t *CV_FindVar(const char *name);
static const char *CV_StringValue(const char *var_name);
static consvar_t *consvar_vars; // list of registered console variables

static char com_token[1024];
static char *COM_Parse(char *data);

CV_PossibleValue_t CV_OnOff[] = {{0, "Off"}, {1, "On"}, {0, NULL}};
CV_PossibleValue_t CV_YesNo[] = {{0, "No"}, {1, "Yes"}, {0, NULL}};
CV_PossibleValue_t CV_Unsigned[] = {{0, "MIN"}, {999999999, "MAX"}, {0, NULL}};
CV_PossibleValue_t CV_Natural[] = {{1, "MIN"}, {999999999, "MAX"}, {0, NULL}};

//SRB2kart
CV_PossibleValue_t kartspeed_cons_t[] = {
	{0, "Easy"}, {1, "Normal"}, {2, "Hard"},
	{0, NULL}};

// Filter consvars by EXECVERSION
// First implementation is 2 (1.0.2), so earlier configs default at 1 (1.0.0)
// Also set CV_HIDEN during runtime, after config is loaded

static boolean execversion_enabled = false;
consvar_t cv_execversion = {"execversion","1",CV_CALL,CV_Unsigned, CV_EnforceExecVersion, 0, NULL, NULL, 0, 0, NULL};

// for default joyaxis detection
#if 0
static boolean joyaxis_default[4] = {false,false,false,false};
static INT32 joyaxis_count[4] = {0,0,0,0};
#endif

#define COM_BUF_SIZE 0x4000 // command buffer size, 0x4000 = 16384
#define MAX_ALIAS_RECURSION 100 // max recursion allowed for aliases

static INT32 com_wait; // one command per frame (for cmd sequences)

// command aliases
//
typedef struct cmdalias_s
{
	struct cmdalias_s *next;
	char *name;
	char *value; // the command string to replace the alias
} cmdalias_t;

static cmdalias_t *com_alias; // aliases list

// =========================================================================
//                            COMMAND BUFFER
// =========================================================================

static vsbuf_t com_text; // variable sized buffer

/** Adds text into the command buffer for later execution.
  *
  * \param ptext The text to add.
  * \sa COM_BufInsertText
  */
void COM_BufAddText(const char *ptext)
{
	size_t l;

	l = strlen(ptext);

	if (com_text.cursize + l >= com_text.maxsize)
	{
		CONS_Alert(CONS_WARNING, M_GetText("Command buffer full!\n"));
		return;
	}
	VS_Write(&com_text, ptext, l);
}

/** Adds command text and executes it immediately.
  *
  * \param ptext The text to execute. A newline is automatically added.
  * \sa COM_BufAddText
  */
void COM_BufInsertText(const char *ptext)
{
	char *temp = NULL;
	size_t templen;

	// copy off any commands still remaining in the exec buffer
	templen = com_text.cursize;
	if (templen)
	{
		temp = M_Memcpy(ZZ_Alloc(templen), com_text.data, templen);
		VS_Clear(&com_text);
	}

	// add the entire text of the file (or alias)
	COM_BufAddText(ptext);
	COM_BufExecute(); // do it right away

	// add the copied off data
	if (templen)
	{
		VS_Write(&com_text, temp, templen);
		Z_Free(temp);
	}
}

/** Progress the wait timer and flush waiting console commands when ready.
  */
void
COM_BufTicker(void)
{
	if (com_wait)
	{
		com_wait--;
		return;
	}

	COM_BufExecute();
}

/** Flushes (executes) console commands in the buffer.
  */
void COM_BufExecute(void)
{
	size_t i;
	char *ptext;
	char line[1024] = "";
	INT32 quotes;

	while (com_text.cursize)
	{
		// find a '\n' or; line break
		ptext = (char *)com_text.data;

		quotes = 0;
		for (i = 0; i < com_text.cursize; i++)
		{
			if (ptext[i] == '\"' && !quotes && i > 0 && ptext[i-1] != ' ') // Malformed command
				break;
			if (ptext[i] == '\"')
				quotes++;
			if (!(quotes & 1) && ptext[i] == ';')
				break; // don't break if inside a quoted string
			if (ptext[i] == '\n' || ptext[i] == '\r')
				break;
		}

		M_Memcpy(line, ptext, i);
		line[i] = 0;

		// flush the command text from the command buffer, _BEFORE_
		// executing, to avoid that 'recursive' aliases overflow the
		// command text buffer, in that case, new commands are inserted
		// at the beginning, in place of the actual, so it doesn't
		// overflow
		if (i == com_text.cursize)
			// the last command was just flushed
			com_text.cursize = 0;
		else
		{
			i++;
			com_text.cursize -= i;
			//memcpy(ptext, ptext+i, com_text.cursize); // Use memmove if the memory areas do overlap.
			memmove(ptext, ptext+i, com_text.cursize);
		}

		// execute the command line
		COM_ExecuteString(line);

		// delay following commands if a wait was encountered
		if (com_wait)
		{
			com_wait--;
			break;
		}
	}
}

/** Executes a string immediately.  Used for skirting around WAIT commands.
  */
void COM_ImmedExecute(const char *ptext)
{
	size_t i = 0, j = 0;
	char line[1024] = "";
	INT32 quotes;

	while (i < strlen(ptext))
	{

		quotes = 0;
		for (j = 0; i < strlen(ptext); i++,j++)
		{
			if (ptext[i] == '\"' && !quotes && i > 0 && ptext[i-1] != ' ') // Malformed command
				return;
			if (ptext[i] == '\"')
				quotes++;
			// don't break if inside a quoted string
			if ((!(quotes & 1) && ptext[i] == ';') || ptext[i] == '\n' || ptext[i] == '\r')
				break;
		}

		memcpy(line, ptext+(i-j), j);
		line[j] = 0;

		// execute the command line
		COM_ExecuteString(line);

		i++; // move to next character
	}
}

// =========================================================================
//                            COMMAND EXECUTION
// =========================================================================

typedef struct xcommand_s
{
	const char *name;
	struct xcommand_s *next;
	com_func_t function;
} xcommand_t;

static xcommand_t *com_commands = NULL; // current commands

#define MAX_ARGS 80
static size_t com_argc;
static char *com_argv[MAX_ARGS];
static const char *com_null_string = "";
static char *com_args = NULL; // current command args or NULL

static void Got_NetVar(UINT8 **p, INT32 playernum);

/** Initializes command buffer and adds basic commands.
  */
void COM_Init(void)
{
	// allocate command buffer
	VS_Alloc(&com_text, COM_BUF_SIZE);

	// add standard commands
	COM_AddCommand("alias", COM_Alias_f);
	COM_AddCommand("echo", COM_Echo_f);
	COM_AddCommand("cecho", COM_CEcho_f);
	COM_AddCommand("cechoflags", COM_CEchoFlags_f);
	COM_AddCommand("cechoduration", COM_CEchoDuration_f);
	COM_AddCommand("exec", COM_Exec_f);
	COM_AddCommand("wait", COM_Wait_f);
	COM_AddCommand("help", COM_Help_f);
	COM_AddCommand("toggle", COM_Toggle_f);
	COM_AddCommand("add", COM_Add_f);
	RegisterNetXCmd(XD_NETVAR, Got_NetVar);
}

/** Gets a console command argument count.
  *
  * \return Number of arguments for the last command.
  * \sa COM_Argv
  */
size_t COM_Argc(void)
{
	return com_argc;
}

/** Gets a console command argument.
  *
  * \param arg Index of the argument (0 to COM_Argc() - 1).
  * \return String pointer to the indicated argument.
  * \sa COM_Argc, COM_Args
  */
const char *COM_Argv(size_t arg)
{
	if (arg >= com_argc || (signed)arg < 0)
		return com_null_string;
	return com_argv[arg];
}

/** Gets all console command arguments.
  *
  * \return String pointer to all arguments for the last command.
  * \sa COM_Argv
  */
char *COM_Args(void)
{
	return com_args;
}

/** Checks if a parameter was passed to a console command.
  *
  * \param check The parameter to look for, e.g. "-noerror".
  * \return The index of the argument containing the parameter,
  *         or 0 if the parameter was not found.
  */
size_t COM_CheckParm(const char *check)
{
	size_t i;

	for (i = 1; i < com_argc; i++)
		if (!strcasecmp(check, com_argv[i]))
			return i;
	return 0;
}

/** \brief COM_CheckParm, but checks only the start of each argument.
  *        E.g. checking for "-no" would match "-noerror" too.
  */
size_t COM_CheckPartialParm(const char *check)
{
	int  len;
	size_t i;

	len = strlen(check);

	for (i = 1; i < com_argc; i++)
	{
		if (strncasecmp(check, com_argv[i], len) == 0)
			return i;
	}
	return 0;
}

/** Find the first argument that starts with a hyphen (-).
  * \return The index of the argument, or 0
  *         if there are no such arguments.
  */
size_t COM_FirstOption(void)
{
	size_t i;

	for (i = 1; i < com_argc; i++)
	{
		if (com_argv[i][0] == '-')/* options start with a hyphen */
			return i;
	}
	return 0;
}

/** Parses a string into command-line tokens.
  *
  * \param ptext A null-terminated string. Does not need to be
  *             newline-terminated.
  */
static void COM_TokenizeString(char *ptext)
{
	size_t i;

	// Clear the args from the last string.
	for (i = 0; i < com_argc; i++)
		Z_Free(com_argv[i]);

	com_argc = 0;
	com_args = NULL;

	while (com_argc < MAX_ARGS)
	{
		// Skip whitespace up to a newline.
		while (*ptext != '\0' && *ptext <= ' ' && *ptext != '\n')
			ptext++;

		// A newline means end of command in buffer,
		// thus end of this command's args too.
		if (*ptext == '\n' || *ptext == '\0')
			break;

		if (com_argc == 1)
			com_args = ptext;

		ptext = COM_Parse(ptext);
		if (ptext == NULL)
			break;

		com_argv[com_argc] = Z_StrDup(com_token);
		com_argc++;
	}
}

/** Adds a console command.
  *
  * \param name Name of the command.
  * \param func Function called when the command is run.
  */
void COM_AddCommand(const char *name, com_func_t func)
{
	xcommand_t *cmd;

	// fail if the command is a variable name
	if (CV_StringValue(name)[0] != '\0')
	{
		I_Error("%s is a variable name\n", name);
		return;
	}

	// fail if the command already exists
	for (cmd = com_commands; cmd; cmd = cmd->next)
	{
		if (!stricmp(name, cmd->name)) //case insensitive now that we have lower and uppercase!
		{
#ifdef HAVE_BLUA
			// don't I_Error for Lua commands
			// Lua commands can replace game commands, and they have priority.
			// BUT, if for some reason we screwed up and made two console commands with the same name,
			// it's good to have this here so we find out.
			if (cmd->function != COM_Lua_f)
#endif
				I_Error("Command %s already exists\n", name);

			return;
		}
	}

	cmd = ZZ_Alloc(sizeof *cmd);
	cmd->name = name;
	cmd->function = func;
	cmd->next = com_commands;
	com_commands = cmd;
}

#ifdef HAVE_BLUA
/** Adds a console command for Lua.
  * No I_Errors allowed; return a negative code instead.
  *
  * \param name Name of the command.
  */
int COM_AddLuaCommand(const char *name)
{
	xcommand_t *cmd;

	// fail if the command is a variable name
	if (CV_StringValue(name)[0] != '\0')
		return -1;

	// command already exists
	for (cmd = com_commands; cmd; cmd = cmd->next)
	{
		if (!stricmp(name, cmd->name)) //case insensitive now that we have lower and uppercase!
		{
			// replace the built in command.
			cmd->function = COM_Lua_f;
			return 1;
		}
	}

	// Add a new command.
	cmd = ZZ_Alloc(sizeof *cmd);
	cmd->name = name;
	cmd->function = COM_Lua_f;
	cmd->next = com_commands;
	com_commands = cmd;
	return 0;
}
#endif

/** Tests if a command exists.
  *
  * \param com_name Name to test for.
  * \return True if a command by the given name exists.
  */
static boolean COM_Exists(const char *com_name)
{
	xcommand_t *cmd;

	for (cmd = com_commands; cmd; cmd = cmd->next)
		if (!stricmp(com_name, cmd->name))
			return true;

	return false;
}

/** Does command completion for the console.
  *
  * \param partial The partial name of the command (potentially).
  * \param skips   Number of commands to skip.
  * \return The complete command name, or NULL.
  * \sa CV_CompleteVar
  */
const char *COM_CompleteCommand(const char *partial, INT32 skips)
{
	xcommand_t *cmd;
	size_t len;

	len = strlen(partial);

	if (!len)
		return NULL;

	// check functions
	for (cmd = com_commands; cmd; cmd = cmd->next)
		if (!strncmp(partial, cmd->name, len))
			if (!skips--)
				return cmd->name;

	return NULL;
}

/** Parses a single line of text into arguments and tries to execute it.
  * The text can come from the command buffer, a remote client, or stdin.
  *
  * \param ptext A single line of text.
  */
static void COM_ExecuteString(char *ptext)
{
	xcommand_t *cmd;
	cmdalias_t *a;
	static INT32 recursion = 0; // detects recursion and stops it if it goes too far

	COM_TokenizeString(ptext);

	// execute the command line
	if (COM_Argc() == 0)
		return; // no tokens

	// check functions
	for (cmd = com_commands; cmd; cmd = cmd->next)
	{
		if (!stricmp(com_argv[0], cmd->name)) //case insensitive now that we have lower and uppercase!
		{
			cmd->function();
			return;
		}
	}

	// check aliases
	for (a = com_alias; a; a = a->next)
	{
		if (!stricmp(com_argv[0], a->name))
		{
			if (recursion > MAX_ALIAS_RECURSION)
				CONS_Alert(CONS_WARNING, M_GetText("Alias recursion cycle detected!\n"));
			else
			{
				char buf[1024];
				char *write = buf, *read = a->value, *seek = read;

				while ((seek = strchr(seek, '$')) != NULL)
				{
					memcpy(write, read, seek-read);
					write += seek-read;

					seek++;

					if (*seek >= '1' && *seek <= '9')
					{
						if (com_argc > (size_t)(*seek - '0'))
						{
							memcpy(write, com_argv[*seek - '0'], strlen(com_argv[*seek - '0']));
							write += strlen(com_argv[*seek - '0']);
						}
						seek++;
					}
					else
					{
						*write = '$';
						write++;
					}

					read = seek;
				}
				WRITESTRING(write, read);

				// Monster Iestyn: keep track of how many levels of recursion we're in
				recursion++;
				COM_BufInsertText(buf);
				recursion--;
			}
			return;
		}
	}

	// check cvars
	// Hurdler: added at Ebola's request ;)
	// (don't flood the console in software mode with bad gr_xxx command)
	if (!CV_Command() && con_destlines)
		CONS_Printf(M_GetText("Unknown command '%s'\n"), COM_Argv(0));
}

// =========================================================================
//                            SCRIPT COMMANDS
// =========================================================================

/** Creates a command name that replaces another command.
  */
static void COM_Alias_f(void)
{
	cmdalias_t *a;

	if (COM_Argc() < 3)
	{
		CONS_Printf(M_GetText("alias <name> <command>: create a shortcut command that executes other command(s)\n"));
		return;
	}

	a = ZZ_Alloc(sizeof *a);
	a->next = com_alias;
	com_alias = a;

	a->name = Z_StrDup(COM_Argv(1));
	// Just use arg 2 if it's the only other argument, in case the alias is wrapped in quotes (backward compat, or multiple commands in one string).
	// Otherwise pull the whole string and seek to the end of the alias name. The strctr is in case the alias is quoted.
	a->value = Z_StrDup(COM_Argc() == 3 ? COM_Argv(2) : (strchr(COM_Args() + strlen(a->name), ' ') + 1));
}

/** Prints a line of text to the console.
  */
static void COM_Echo_f(void)
{
	size_t i;

	for (i = 1; i < COM_Argc(); i++)
		CONS_Printf("%s ", COM_Argv(i));
	CONS_Printf("\n");
}

/** Displays text on the center of the screen for a short time.
  */
static void COM_CEcho_f(void)
{
	size_t i;
	char cechotext[1024] = "";

	for (i = 1; i < COM_Argc(); i++)
	{
		strncat(cechotext, COM_Argv(i), sizeof(cechotext)-1);
		strncat(cechotext, " ", sizeof(cechotext)-1);
	}

	cechotext[sizeof(cechotext) - 1] = '\0';

	HU_DoCEcho(cechotext);
}

/** Sets drawing flags for the CECHO command.
  */
static void COM_CEchoFlags_f(void)
{
	if (COM_Argc() > 1)
	{
		const char *arg = COM_Argv(1);

		if (arg[0] && arg[0] == '0' &&
			arg[1] && arg[1] == 'x') // Use hexadecimal!
			HU_SetCEchoFlags(axtoi(arg+2));
		else
			HU_SetCEchoFlags(atoi(arg));
	}
	else
		CONS_Printf(M_GetText("cechoflags <flags>: set CEcho flags, prepend with 0x to use hexadecimal\n"));
}

/** Sets the duration for CECHO commands to stay on the screen
  */
static void COM_CEchoDuration_f(void)
{
	if (COM_Argc() > 1)
		HU_SetCEchoDuration(atoi(COM_Argv(1)));
}

/** Executes a script file.
  */
static void COM_Exec_f(void)
{
	UINT8 *buf = NULL;
	char filename[256];

	if (COM_Argc() < 2 || COM_Argc() > 3)
	{
		CONS_Printf(M_GetText("exec <filename>: run a script file\n"));
		return;
	}

	// load file
	// Try with Argv passed verbatim first, for back compat
	FIL_ReadFile(COM_Argv(1), &buf);

	if (!buf)
	{
		// Now try by searching the file path
		// filename is modified with the full found path
		strcpy(filename, COM_Argv(1));
		if (findfile(filename, NULL, true) != FS_NOTFOUND)
			FIL_ReadFile(filename, &buf);

		if (!buf)
		{
			if (!COM_CheckParm("-noerror"))
				CONS_Printf(M_GetText("couldn't execute file %s\n"), COM_Argv(1));
			return;
		}
	}

	if (!COM_CheckParm("-silent"))
		CONS_Printf(M_GetText("executing %s\n"), COM_Argv(1));

	// insert text file into the command buffer
	COM_BufAddText((char *)buf);
	COM_BufAddText("\n");

	// free buffer
	Z_Free(buf);
}

/** Delays execution of the rest of the commands until the next frame.
  * Allows sequences of commands like "jump; fire; backward".
  */
static void COM_Wait_f(void)
{
	if (COM_Argc() > 1)
		com_wait = atoi(COM_Argv(1));
	else
		com_wait = 1; // 1 frame
}

/** Prints help on variables and commands.
  */
static void COM_Help_f(void)
{
	xcommand_t *cmd;
	consvar_t *cvar;
	INT32 i = 0;

	if (COM_Argc() > 1)
	{
		const char *help = COM_Argv(1);
		cvar = CV_FindVar(help);
		if (cvar)
		{
			CONS_Printf("\x82""Variable %s:\n", cvar->name);
			CONS_Printf(M_GetText("  flags :"));
			if (cvar->flags & CV_SAVE)
				CONS_Printf("AUTOSAVE ");
			if (cvar->flags & CV_FLOAT)
				CONS_Printf("FLOAT ");
			if (cvar->flags & CV_NETVAR)
				CONS_Printf("NETVAR ");
			if (cvar->flags & CV_CALL)
				CONS_Printf("ACTION ");
			if (cvar->flags & CV_CHEAT)
				CONS_Printf("CHEAT ");
			CONS_Printf("\n");
			if (cvar->PossibleValue)
			{
				if (!stricmp(cvar->PossibleValue[0].strvalue, "MIN") && !stricmp(cvar->PossibleValue[1].strvalue, "MAX"))
				{
					CONS_Printf("  range from %d to %d\n", cvar->PossibleValue[0].value,
						cvar->PossibleValue[1].value);
					i = 2;
				}

				{
					const char *cvalue = NULL;
					//CONS_Printf(M_GetText("  possible value : %s\n"), cvar->name);
					while (cvar->PossibleValue[i].strvalue)
					{
						CONS_Printf("  %-2d : %s\n", cvar->PossibleValue[i].value,
							cvar->PossibleValue[i].strvalue);
						if (cvar->PossibleValue[i].value == cvar->value)
							cvalue = cvar->PossibleValue[i].strvalue;
						i++;
					}
					if (cvalue)
						CONS_Printf(" Current value: %s\n", cvalue);
					else
						CONS_Printf(" Current value: %d\n", cvar->value);
				}
			}
			else
				CONS_Printf(" Current value: %d\n", cvar->value);
		}
		else
		{
			for (cmd = com_commands; cmd; cmd = cmd->next)
			{
				if (strcmp(cmd->name, help))
					continue;

				CONS_Printf("\x82""Command %s:\n", cmd->name);
				CONS_Printf("  help is not available for commands");
				CONS_Printf("\x82""\nCheck wiki.srb2.org for more or try typing <name> without arguments\n");
				return;
			}

			CONS_Printf("No exact match, searching...\n");
			// commands
			CONS_Printf("\x82""Commands:\n");
			for (cmd = com_commands; cmd; cmd = cmd->next)
			{
				if (!strstr(cmd->name, help))
					continue;
				CONS_Printf("%s ",cmd->name);
				i++;
			}

			// variables
			CONS_Printf("\x82""\nVariables:\n");
			for (cvar = consvar_vars; cvar; cvar = cvar->next)
			{
				if ((cvar->flags & CV_NOSHOWHELP) || (!strstr(cvar->name, help)))
					continue;
				CONS_Printf("%s ", cvar->name);
				i++;
			}

			CONS_Printf("\x82""\nCheck wiki.srb2.org for more or type help <command or variable>\n");

			CONS_Debug(DBG_GAMELOGIC, "\x87Total : %d\n", i);
		}
		return;
	}

	{
		// commands
		CONS_Printf("\x82""Commands:\n");
		for (cmd = com_commands; cmd; cmd = cmd->next)
		{
			CONS_Printf("%s ",cmd->name);
			i++;
		}

		// variables
		CONS_Printf("\x82""\nVariables:\n");
		for (cvar = consvar_vars; cvar; cvar = cvar->next)
		{
			if (cvar->flags & CV_NOSHOWHELP)
				continue;
			CONS_Printf("%s ", cvar->name);
			i++;
		}

		CONS_Printf("\x82""\nCheck wiki.srb2.org for more or type help <command or variable>\n");

		CONS_Debug(DBG_GAMELOGIC, "\x82Total : %d\n", i);
	}
}

/** Toggles a console variable. Useful for on/off values.
  *
  * This works on on/off, yes/no values only
  */
static void COM_Toggle_f(void)
{
	consvar_t *cvar;

	if (COM_Argc() != 2)
	{
		CONS_Printf(M_GetText("Toggle <cvar_name>: Toggle the value of a cvar\n"));
		return;
	}
	cvar = CV_FindVar(COM_Argv(1));
	if (!cvar)
	{
		CONS_Alert(CONS_NOTICE, M_GetText("%s is not a cvar\n"), COM_Argv(1));
		return;
	}

	if (!(cvar->PossibleValue == CV_YesNo || cvar->PossibleValue == CV_OnOff))
	{
		CONS_Alert(CONS_NOTICE, M_GetText("%s is not a boolean value\n"), COM_Argv(1));
		return;
	}

	// netcvar don't change imediately
	cvar->flags |= CV_SHOWMODIFONETIME;
	CV_AddValue(cvar, +1);
}

/** Command variant of CV_AddValue
  */
static void COM_Add_f(void)
{
	consvar_t *cvar;

	if (COM_Argc() != 3)
	{
		CONS_Printf(M_GetText("Add <cvar_name> <value>: Add to the value of a cvar. Negative values work too!\n"));
		return;
	}
	cvar = CV_FindVar(COM_Argv(1));
	if (!cvar)
	{
		CONS_Alert(CONS_NOTICE, M_GetText("%s is not a cvar\n"), COM_Argv(1));
		return;
	}

	if (( cvar->flags & CV_FLOAT ))
		CV_Set(cvar, va("%f", FIXED_TO_FLOAT (cvar->value) + atof(COM_Argv(2))));
	else
		CV_AddValue(cvar, atoi(COM_Argv(2)));
}

// =========================================================================
//                      VARIABLE SIZE BUFFERS
// =========================================================================

/** Initializes a variable size buffer.
  *
  * \param buf      Buffer to initialize.
  * \param initsize Initial size for the buffer.
  */
void VS_Alloc(vsbuf_t *buf, size_t initsize)
{
#define VSBUFMINSIZE 256
	if (initsize < VSBUFMINSIZE)
		initsize = VSBUFMINSIZE;
	buf->data = Z_Malloc(initsize, PU_STATIC, NULL);
	buf->maxsize = initsize;
	buf->cursize = 0;
#undef VSBUFMINSIZE
}

/** Frees a variable size buffer.
  *
  * \param buf Buffer to free.
  */
void VS_Free(vsbuf_t *buf)
{
	buf->cursize = 0;
}

/** Clears a variable size buffer.
  *
  * \param buf Buffer to clear.
  */
void VS_Clear(vsbuf_t *buf)
{
	buf->cursize = 0;
}

/** Makes sure a variable size buffer has enough space for data of a
  * certain length.
  *
  * \param buf    The buffer. It is enlarged if necessary.
  * \param length The length of data we need to add.
  * \return Pointer to where the new data can go.
  */
void *VS_GetSpace(vsbuf_t *buf, size_t length)
{
	void *data;

	if (buf->cursize + length > buf->maxsize)
	{
		if (!buf->allowoverflow)
			I_Error("overflow 111");

		if (length > buf->maxsize)
			I_Error("overflow l%s 112", sizeu1(length));

		buf->overflowed = true;
		CONS_Printf("VS buffer overflow");
		VS_Clear(buf);