SYNOPSIS
	int trace(int traceflags)

DESCRIPTION
	Sets the trace flags and returns the old trace flags. When
	tracing is on, a lot of information is printed during
	execution and too much output can crash your connection or
	even the whole driver.
	Tracing is done on a per-connection basis: each interactive(!)
	user may specifiy its own tracelevel and -prefix. Each gets the
	traceoutput for just the code executed during the evaluation
	of the commands he entered.
	
	The trace bits are:
	
	1 Trace all function calls to lfuns.
	
	2 Trace all calls to call_other
	
	4 Trace all function returns.
	
	8 Print argunents at function calls and return values.
	
	16 Print all executed stack machine instructions (Avoid this
	flag, it produces massive output!).
	
	32 Enable trace in heart beat functions (Avoid this flag, it
	constantly produces a lot of output!).
	
	64 Trace calls to apply (Applies are driver internal
	call_others).
	
	128 Show object name in tracing (Avoid this flag when you know
	what you are tracing!).


	The master-lfun query_player_level() is called to verify the
	usage of this efun.

EXAMPLE
	object obj;
	string prefix;
	obj=find_player("deepthought");
	prefix=file_name(obj);
	prefix=prefix[1..strlen(prefix)-1]; /* cut off the leading "/" */
	traceprefix(prefix);
	  /* From here on, only code in the object "std/player#69"
	   * will be traced.
           */
	trace(1|2|4|8);
	...
	trace(0);
	
SEE ALSO
	traceprefix(E)
