Site Specific JS

Description

This patch allows scripts to be injected based on the url matching a regex, allowing scripts to be site-specfic.

It also can serve as a more complex replacement for the multijs patch.

In your config.h:

static char *scriptdir      = "~/.surf/scripts/";
static SiteSpecific scripts[] = {

    /* regexp                script in $scriptdir */
    { "://duckduckgo\\.com", "example.js" },

};