REBOL 3 Concepts: Tour: Scripts

Pending Revision

This document was written for R2 and has yet to be revised for R3.

OLD DOCS

This section is obsolete and being replaced. It is kept only as a source for new content.

A script is a file that holds a block that can be loaded and evaluated. The block can contain code or data, and typically contains a number of sub-blocks.

Scripts require a header to identify the presence of code. The header can include the script title, date, and other information. In the following example of a script, the first block contains the header information:

REBOL [
    Title: "Web Page Change Detector"
    File:  %webcheck.r
    Author: "Reburu"
    Date:  20-May-1999
    Purpose: {
        Determine if a web page has changed since it was
        last checked, and if it has, send the new page
        via email.
    }
    Category: [web email file net 2]
]

page: read http://www.rebol.com

page-sum: checksum page

if any [
    not exists? %page-sum.r
    page-sum <> (load %page-sum.r)
][
    print ["Page Changed" now]
    save %page-sum.r page-sum
    send luke@rebol.com page
]