[E-devel] eesh with libeditline and libedit

[Ralf A. <ral...@gm...>]

Hi,

last month using libeditline or libedit with eesh was briefly
discussed. Since having no history and no decent line editing in eesh
has annoyed me for ages, I gave it a try.

My qualification for this job was (and still is) outstanding: I didn't
know anything about X11 programming till last sunday, I haven't
written a line of C in the last two years (and not really much before
either), and I never used libreadline, libeditline or libedit. So
please have a look at my code if i'm doing something stupid.

Furthermore I don't know anything about autoconf or automake. So I
just hacked the auto-generated "Makefile" to link to libeditline and
libedit (no patch attached).

Because I couldn't connect to the CVS server of sourceforge last
friday, I used enlightenment-0.16.7-0.65.tar.gz as a template. Since
main.c of eesh isn't that large I'll mail the complete file and not a
patch (see attachment). I introduced to #defines, USE_EDITLINE and
USE_EDIT, to control which library is used.

About libedit: you can use $HOME/.editrc to configure it, e.g. "bind
-v" invokes vi keyset, see editrc (5el).

My setup:
    Debian testing/unstable
    official Debian enlightenment 0.16.6-1 (I'm just using eesh from
        0.16.7 to talk to it, maybe I shouldn't this?)
    official Debian libeditline0 1.12-5
    official Debian libedit2 2.6.cvs.200201

Why did I implement it this way:
    1) The prompt: to see if the user can type now. I could get rid of
       it when everything works. IMHO it looks better with a prompt.

    2) I couldn't just replace the lines
          k = 0;
            while ((ret = read(0, &(buf[j]), 1) > 0))
              {
                ...
       with the appropriate code for editline/edit or leaving the
       whole FD_SET-select-stuff out because
         a) the prompt resp. input will be messed up:
            no prompt shows but you can write without visible
            line-editing, type <ENTER> and the prompt shows with the
            text the user entered before including the line-editing,
            e.g. history.
         b) no output shows.
         c) if the eesh command doesn't produce any output
         d) misc. other symptoms (I went through several stages to get
            to the present state, I don't want to recount everything.)

       So I had use two fd_set variables and two calls to select: one,
       which looks for readfds and writefds, and another, which only
       looks for readfds. BTW, I could use only one variable and clear
       it by FD_ZERO, any preferences on your side?

       Maybe this is all self-evident to you but I included it because
       I hope it is easier for you to spot any errors.

Bugs:
    - <CTRL d> doesn't quit the interactive mode, use <CTRL c>
    - libeditline: type <CTRL d> => segfault
    - libedit: type <CTRL d>, line-editing etc. don't work anymore;
      just continue typing, focus other windows, re-focus eesh,
      do whatever, eventually it will work again
    - just type <ENTER>, mostly the terminal hangs; focus another
      window, focus terminal with eesh again, get a new prompt
    - the indent isn't consistent with the rest of the file, I'll
      correct this for the final patch
    - I'm sure there are others, we just have to find them :-)


First of all I'd be grateful if someone could look over my code and
tell me if there any obvious errors (see my programming skills above).


Ralf

PS: I hope my further mails will be shorter. :-)