// $Header$#ifndef executable_h#define executable_h// Searches PATH for the given executable; returns a malloc()'d copy// of the path to the executable, which the caller should delete when// done with.char* which_executable( const char* exec_name );class Executable {    public:	Executable( const char* arg_executable );	virtual ~Executable();	int ExecError()	{ return exec_error; }	// true if the executable is still "out there"	virtual int Active() = 0;	virtual void Ping() = 0;    protected:	char* executable;	int exec_error;	int has_exited;	};#endif	/* executable_h */