A small emacs-lisp package that I wrote (eev.el - URL below) defines
some lisp functions that can be used as hyperlinks and some commands
to execute blocks of text; for example, in the chunk of text below,

  # (find-node "(gawk)Top")
  # (find-node "(gawk)If Statement")
  # (find-node "(gawk)String Functions" "substr(")

  cd $ES/
  for i in *.e; do
    echo -n "$i: "
    awk '{if ($0=="#") {if (n==1) exit; else n+=1}
          else if (n==1) print substr($0, 3)
         }' $i
  done | tee ~/o

if you place the cursor at the end of the last "find-node" line and
type C-x C-e then Emacs evaluates the Lisp expression

  (find-node "(gawk)String Functions" "substr(")

which corresponds to `find the info page named "String Functions" in
the gawk info pages, and place the cursor after the first occurrence
of "substr(". There are variations like

  (find-fline "/usr/include/linux/kd.h" 11)
  (find-k2file "drivers/char/vt.c" "PIO_FONTX")
  (find-k2tag "vt_ioctl")

which mean, respectively, `open the file /usr/include/linux/kd.h and
go to the line 11', `open the file
/usr/src/linux-2.0/drivers/char/vt.c and search for "PIO_FONTX"', and
`find the tag "vt_ioctl" in the kernel 2.0.37 sources, i.e., using the
tags table /usr/src/linux-2.0/TAGS'. As any of these "hyperlinks" can
be written preceded by a "#", we become able to, for example, place
hyperlinks in our shell scripts...

  As for executing blocks of text, if you mark a portion of your text,
say from `# (find-node "(gawk)Top")' to `done | tee ~/o', and then
type M-x eev (the name of this function doesn't make much sense, but I
use it so much that I had to choose something short), then you can go
to another window or virtual console and run `ee', and the shell will
execute the marked block almost as if you were typing it line by line,
i.e, displaying each line (including blanks and comments) before
executing it, and, if needed, accumulating many lines before running
them together, as in the case of the "for" loop. There are some
variations on eev that are meant to execute blocks of text using Tcl,
Forth, gdb or perl and to run a block through LaTeX, putting some
predefined lines before and after it.

  Well, the moral of all this is that one can keep files of notes with
lots of comments and hyperlinks, instead of having to keep hundreds of
possibly incomplete scripts, and the "code" in these notes can be
executed in little pieces; so we can just store the commands that
accomplished something on one day, and as we use them more we can
clean our preferred ones and make them more general... it's more
organic than having to choose between "turn into a named script and
document it", "describe everything in terms of `type this, run that'",
and "Oh, I think I will remember it when I need to".

  I think that people should have better ways to exchange tricks than
only by scripts, source, books and verbal descriptions, and this is my
contribution to it. This way obviously sprang out from my own needs,
my laziness and the necessity to cope with my very weak memory... I've
spent four years thinking that everybody was doing like me, until I
found -- shocked and horrified -- that it was not the case... Well,
too much wistory. Back to the main points:

  I have about 1M just on notes of this kind, which I call
"e-scripts". They're temporarily at angelfire; my page there is

  http://www.angelfire.com/or2/edrx/ .

It is grossly incomplete; the server I used at my university went down
some weeks ago (it was a vulnerable RedHat box) and I was trying to
use angelfire, but at a.f. some filenames, like .emacs, are not
allowed and I can't generate all the stuff from a 300k .tar.gz and a
makefile, not to count that all the htmls get banners...