var exec_perl = require( "exec_perl").exec_perl ;
$abc = "yes";

exec_perl( '$abc', ` $abc =~ s/yes/YES/g; (($abc)); ` );
console.log ( $abc );  
// =>  YES

var exec_perl = require('exec_perl').exec_perl;  
 // if not use global: 
 // var app_e_p = require('exec_perl') ; 
 // app_e_p.exec( a,b );

/* important */
/* important */
/* important */
// variable in exel_perl must be a global var
$abc = 'text of $abc var.';	
var perl_stm = 	`
	 $abc= $abc x 2;
	 $abc =~ s/text/TEXT/g; // use your comment
	 (($abc));  # another comment style,define return var
`;

// var ret_obj = app.e_pl ()... // also works 
var ret_obj = exec_perl ( 
	'$abc', 	// caution! it's name of var, not value
	perl_stm
);
console.log( $abc ) ; 
// =>  TEXT of $abc var.TEXT of $abc var.
// console.log ( ret_obj.ans );
// console.log ( ret_obj.perl_stm ); // show the run statement,for debugging