UTIL VarArgs: Difference between revisions

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This function will build a C-String similar to printf. It is server-side only!
{{wrongtitle|UTIL_VarArgs}}
'''UTIL_VarArgs''' is a [[UTIL]] provided to build a C-String similar to printf. This is only available on the '''server'''. It is useful for quickly building a composite string.


Example:
== Usage ==
<code>
<source lang=cpp>
//-----------------------------------------------------------------------------
// Purpose: Prints a message to console
// Input  : format - See examples
// Output : a char-array that is easily used in Msg, etc.
//-----------------------------------------------------------------------------
char *UTIL_VarArgs( char *format, ... )
{
va_list argptr;
static char string[1024];
va_start (argptr, format);
Q_vsnprintf(string, sizeof(string), format,argptr);
va_end (argptr);


return string;
}
</source>
== Examples ==
<source lang=cpp>
int iCreepers = 3;
int iCreepers = 3;


char * pFortress = "My Awesome Fort.";
char * pFortress = "My Awesome Fort.";
char * pOutput = UTIL_VarArgs( "There are %i creepers outside of your %s.", iCreepers, pFortress );


char * pOutput = UTIL_VarArgs( "There are %i creepers outside of your %s.", iCreepers, pFortress );
Msg("%s", pOutput );


Msg("%s", output);
//Prints: There are 3 creepers outside of your My Awesome Fortress.
</source>


<source lang=cpp>
//This example uses a UTIL_VarArgs to prefix a string, and then execute a console command.
void CPointDevShotCamera::DevShotThink_TakeShot( void )
{
// Take the screenshot
CBasePlayer *pPlayer = UTIL_GetLocalPlayerOrListenServerHost();
if ( !pPlayer )
return;


//  prints: There are 3 creepers outside of your My Awesome Fortress.
engine->ClientCommand( pPlayer->edict(), UTIL_VarArgs( "devshots_screenshot \"%s\"", STRING(m_iszCameraName) ) );
</code>


This is useful for quickly building a composite string.
// Now take the shot next frame
SetThink( &CPointDevShotCamera::DevShotThink_PostShot );
SetNextThink( gpGlobals->curtime + (DEVSHOT_INTERVAL - 1) );
}
</source>


<code>
<source lang=cpp>
char * pOutput = UTIL_VarArgs( "X:%f Y:%f Z:%f\n", vec.x, vec.y, vec.z );
//This example gets the current map name, and appends it onto the end of a prefix string
</code>
//It's used to find per-map files, such as custom soundscapes.
const char *mapname = STRING( gpGlobals->mapname );
const char *mapSoundscapeFilename = NULL;
if ( mapname && *mapname )
{
mapSoundscapeFilename = UTIL_VarArgs( "scripts/soundscapes_%s.txt", mapname );
}
</source>
[[Category:Programming]]
[[Category:UTIL]]

Revision as of 19:43, 11 April 2011

Template:Wrongtitle UTIL_VarArgs is a UTIL provided to build a C-String similar to printf. This is only available on the server. It is useful for quickly building a composite string.

Usage

//-----------------------------------------------------------------------------
// Purpose: Prints a message to console
// Input  : format - See examples
// Output : a char-array that is easily used in Msg, etc.
//-----------------------------------------------------------------------------
char *UTIL_VarArgs( char *format, ... )
{
	va_list		argptr;
	static char		string[1024];
	
	va_start (argptr, format);
	Q_vsnprintf(string, sizeof(string), format,argptr);
	va_end (argptr);

	return string;	
}

Examples

int iCreepers = 3;

char * pFortress = "My Awesome Fort.";
char * pOutput = UTIL_VarArgs( "There are %i creepers outside of your %s.", iCreepers, pFortress );

Msg("%s", pOutput );

//Prints: There are 3 creepers outside of your My Awesome Fortress.
//This example uses a UTIL_VarArgs to prefix a string, and then execute a console command.
void CPointDevShotCamera::DevShotThink_TakeShot( void )
{
	// Take the screenshot
	CBasePlayer *pPlayer = UTIL_GetLocalPlayerOrListenServerHost();
	if ( !pPlayer )
		return;

	engine->ClientCommand( pPlayer->edict(), UTIL_VarArgs( "devshots_screenshot \"%s\"", STRING(m_iszCameraName) ) );

	// Now take the shot next frame
	SetThink( &CPointDevShotCamera::DevShotThink_PostShot );
	SetNextThink( gpGlobals->curtime + (DEVSHOT_INTERVAL - 1) );
}
//This example gets the current map name, and appends it onto the end of a prefix string
//It's used to find per-map files, such as custom soundscapes.
const char *mapname = STRING( gpGlobals->mapname );
const char *mapSoundscapeFilename = NULL;
if ( mapname && *mapname )
{
	mapSoundscapeFilename = UTIL_VarArgs( "scripts/soundscapes_%s.txt", mapname );
}