Everything cool has already been done

I guess I shouldn't be surprised by anything that turns up within a million-line codebase, but I was. I had been looking around for a way to keep contacts, you know, collections of vital stats: name, e-mail address and if I have it postal address. I've had such a file hanging around for years now my nickname for it is snailmail. I know that the term has traditionally meant more or less: "things one can send through the postal service." But seeing as how e-mail is dead (TIC), it grows increasingly apropos. But anyway, I digress. I have this file of info and I wanted to keep it up to date, generate lists of names, generate those mailto: links and etc. In keeping with what I feel is the the *NIX way, I thought I should create a bunch of shell scripts that operate on my flat file in various ways. So I wrote a few scripts that would dig through the file and spit out whatever it was that I wanted. Okay, I can't resist, I wanted to include one of the ones that I wrote in scheme (guile):

snails.scm

#!/usr/bin/guile -s
!#
(use-modules (ice-9 rdelim))

(define (unpack-snailmail line)
"Currently, this is just ::e-mail"
(let ((line-elts (string-split line #\:)))
(format #t "\"~a ~a\" <~a>~%" (cadr line-elts) (car line-elts)
   (caddr line-elts))))

(define (read-lines port f)
"Read all the lines of a file found at port , applying f"
(let ((current-line (read-line port)))
(if (not (eof-object? current-line))
(begin
 (f current-line)
 (read-lines port f)))))

; rudimentary error-checking on the command line
(if (< (length (command-line)) 2)
    (display "Usage: snail snailmail.db\n")
    (read-lines (open-file (cadr (command-line)) "r") 
                unpack-snailmail))

So it is cake to read out the lines of this file. What I wondered more about was how to update and tend this file? Emacs to the rescue! I found out about forms-mode this does what you would expect, that is to create and fill out forms. There are two components to the form, the first is your data file. In my case it looks like this

.snails

Lastname0:Firstname0:E-mail_address0
Lastname1:Firstname1:E-mail_address1

And so on. Next we need an emacs lisp file to tell Emacs how to parse that file and what the form should look like:

sform.el

;; -*- mode: forms -*-
;; This is the 'Control file' (see 'info forms') for .snails
(setq forms-file "~/.snails")
(setq forms-format-list
 (list
  ",------------------,\n"
  "| Snail Mail Ver 1 |\n"
  "'------------------'\n\n"
  "First:   " 2 "\n"
  "Last:    " 1 "\n"
  "E-mail:  " 3 "\n"))
(setq forms-number-of-fields 3)
(setq forms-field-sep ":")

When you launch emacs and point it at that file emacs -nw sform.el, emacs will ask if you want parse it (answer 'yes') And then there are helpful commands at the bottom of the screen. The only basic one omitted is the one to create new entries, C-c C-o does the trick.