Network Security Tools

Arrays and Hashes

An array is a collection of numbers or strings that can be indexed using a numeric subscript. Consider the following NASL script:

myarray=make_list(1,"two");
display("The value of the first item is ",myarray[0]," \n");
display("The value of the second item is ",myarray[1]," \n");

The script displays the following when executed:

The value of the first item is 1
The value of the second item is two

Notice that the array subscripts begin at 0, and that is why the first element is obtained using the [0] subscript.

Like arrays, hashes are also collections of numbers or strings. However, elements in hashes have a key value associated with them that can be used to obtain the element. You can use the make_array( ) function call to define a hash. Because every element must have an associated key value, the function call requires an even number of arguments. The following is a definition of a hash that contains port numbers for the Telnet protocol (port 23) and HTTP (port 80):

myports=make_array('telnet',23,'http',80);

Now, myports['telnet'] gives you the value of 23, while myports['http'] evaluates to 80.