gistfile1.js

function degrees2dezimal(a) {
 
    var a, h=0, m=0, s=0;
    
    a = a.split("°");

    h = parseInt(a[0].replace(/N|S|O|W/, ""), 10);
    h = isNaN(h) ? 0 : h;

    if (a.length > 1) {
        a = a[1].split("'");
        m = parseInt(a[0], 10);
        m = isNaN(m) ? 0 : m / 60;

        if (a.length > 1) {
            a = a[1].split('"');
            s = parseInt(a[0], 10);
            s = isNaN(s) ? 0 : s / 3600;
        }
    }
    
    return h + m + s;
}

if (typeof process != "undefined" && typeof process.argv[2] == "undefined") {

    console.log("usage: node " + process.argv[1] + " \"102°03'W\"")

} else if(typeof process != "undefined" && typeof process.argv[2] == "string") {

    console.log(degrees2dezimal(process.argv[2]));
}