Command line history for magic

This patch, to the file textio/txInput.c in the magic source tree,
gives the magic use the benefit command-line history on all full-text
lines entered, usually the commands proceeded by ':'.  This is very
helpful for doing repetitive work, for example labeling a lot of
nodes.

The patch has been tested on magic 6.5.1, and magic 6.3, but I think
it should work on most any decendant of magic v6.

In addition to patching txInput.c, you need one of these
command-line-editing libaries:
	- GNU Readline 2.1 or 2.2.1
	- Editline by Rich Salz and Simmule Turner, with a minor patch

Editline is much smaller and simpler than GNU readline, but feels
about the same.  What you give up with editline is the ability to
rebind keys, vi-mode, and the ability to enter lines that are wider
than the terminal.

If using GNU readline 2.1 or later (earlier versions won't work),
 unpack readline in a seperate directory, run configure and then make.  This
builds libreadline.a.  In the magic directory, add "-DUSE_READLINE" to the
file misc/CFLAGS, and add "-lreadline -ltermcap" to the file magic/LIBS, and
rebuild magic.

If using editline version 1.11, patch editline.c with the file
editline.patch.  Editline's interface is similar to GNU readline, but
this tweaks it to add a few Readline-2.1 features that we need.  Edit
editline's makefile, and build libedit.a with "make."  In the magic
directory, add "-DUSE_READLINE" to the file misc/CFLAGS, and add
"-lreadline -ltermcap" to the file magic/LIBS, and rebuild magic.

The following are available from <URL:http://www.cs.unc.edu/~tell/dist>:
magic-readline.README - this file
magic-readline.tar.gz - contains
	README - this file
	txInput.c.patch - patch for magic/textio/txInput.c
	editline.c.patch - patch for editline version 1.11
editline.tar.gz - unmodified editline source
readline-2.2.1.tar.gz - unmodified GNU readline source

Other sources for readline include prep.ai.mit.edu and all of the GNU
mirrors.  Other sources for editline.tar.gz include
ftp://ftp.pipex.net/people/tim/


Steve Tell
tell@cs.unc.edu
September 11, 1997
updated October 21, 1998