#define CODE_EXPANDER
#include <back.h>
#include <assert.h>
#include <system.h>

extern int B_busy; 

int C_open( filename)
char *filename;
{
	assert( !B_busy);

	if ( !open_back( filename)) {
		fprint( STDERR, "Couldn't open %s\n", filename);
		return( 0);
	}
	B_busy = 1;
	return( 1);
}