🚀 go-pugleaf

In article <1990Oct19.170143.7674@polyof.poly.edu> mhoffman@george.poly.edu writes:
>
>	I am working on a senior project to rewrite the history function for    UNIX.  My goal is to have the new history functon work like it does in MS_DOS.
>i.e. I want to be able to call up past commands and edit them by using the 
>control <hjkl> characters.  Additionally, I would like to write this as a stand alone program so that I do not have to rewrite the shell.

	I've written the such program (it's about 50 lines :-) sorry
	but I haven't it handy. To use it one should add the following
	alias to .cshrc:

		alias r 'eval `history | redo`'

	so if you want to edit previous lines you should enter the
	command r.

	This program was died because we (Sergey Ryzhkov & I) have made
	our own revision of csh with builtin line-editing facility.
	(So there is no need to enter commands to go to editing mode).

	It was not so simple because Unix tty drivers handle modes switching
	in the very *ugly* way - I've spent a week trying to make a
	sequence allowing do it without flushing characters. (Oh I use
	to type commands *before* a prompt appears :-).  Another
	problem was the proper processing of ^Z and ^Y - some our
	ttys used this chars (as well as ^Q and ^S) in escape sequences.
	We decided to read all characters as ordinary ones and
	process it in program - and I had to hack tty driver to allow
	TIOCSTART and TIOCSTOP to work with ordinary ttys as well as with
	ptys. Problem with ^Z/^Y was solved by non-trivial hack in csh's
	internals. Anyway it was done and works under DEMOS 2.2.

	Thus I suggest you to do the thing in the first way, it's
	much simplier and practically as suitable as the second for
	an endluser.

	Vadim Antonov
	DEMOS, Moscow, USSR

In article <1990Oct19.170143.7674@polyof.poly.edu> mhoffman@george.poly.edu writes:
>	I am working on a senior project to rewrite the history function for    UNIX.  My goal is to have the new history functon work like it does in MS_DOS.
>i.e. I want to be able to call up past commands and edit them by using the 
>control <hjkl> characters.  Additionally, I would like to write this as a stand alone program so that I do not have to rewrite the shell.


We have a shell script which lets you edit history commands
before they are reexecuted.
-ping

	The main approach I will use will be to store the previous commands in alinked list.  My only problem is that I do not know how to intercept the commandonce it has been entered, before it gets executed.  Likewise, I do ont know how to execute the command once I have retreived it form the list. i.e. I want to   display the command for possible editting and execute it when the carriage
return is pressed.
Thank You.			Mark
----------

If your version of un*x supports the command script, you may extract the
history from the script output file.  script is a terminal session
recorder.

>which may be ugly, but is quite convenient.  But ksh won't do asynch job
>notification, key rebinding, or spelling correction, so I'm stuck with an
>abomination of a shell.

  You can get asynch job notification in ksh88 by doing:

	trap "jobs -n" CHLD


Peter McLain                                          Hewlett-Packard
                                                      3404 East Harmony Road
pbm%hpfclj@hplabs.HP.COM                              Fort Collins
UUCP: hplabs!hpfcla!pbm                               CO          80525-9599

In article <32120001@hpfcdc.HP.COM> pbm@hpfcdc.HP.COM (Peter McLain) writes:
>  You can get asynch job notification in ksh88 by doing:
>
>	trap "jobs -n" CHLD

Which reminds me; why, in sh(1), does

	trap 'echo foo' 18

(where signal 18 is SIGTSTP) give a '18: bad trap' message?
The manual page (Ultrix 3.1) says that SIGCONT, SIGSTOP,
and SIGKILL are the only untrappable signals.

Dang it!  I _want_ to do some massaging on a ^Z!

				--Blair
				  "Gadzooks!  I _asked_ one... :-/"

Several people suggested:

>   You can get asynch job notification in ksh88 by doing:
> 
> 	trap "jobs -n" CHLD

This is almost, but not quite, good enough for what I want.  I want
to be able to emulate both the csh "set notify" command and the csh
"notify" command.  The above emulates only the "set notify" command.
Here's a message I set to Korn on this subject some time ago:

From shannon Sat May 27 02:24:58 1989
To: dgk@ulysses.att.com
Subject: traps

I'm playing around with trapping SIGCHLD to emulate the csh notify
command.  the following code in io_intr() causes a newline to be
printed every time you execute the trap handler, even if it produces
no other output.

		if(sh.trapnote&TRAPSET)
		{
			newline();
			fp = st.standin;
			sh_chktrap();
			io_clear(fp);
			return(0);
		}

for example, do

	trap true CHLD
	sleep 5 &

there might be cases where the newline is helpful, but in this
case it makes it impossible for me to do what I want to do.
(that coupled with the fact that functions can't effect the traps
of the mainline shell.  otherwise I could set and unset the trap
when necessary and that might be good enough.)

how do you feel about removing that call to newline(), or at least
making it conditional on something so it won't happen when catching
SIGCHLD?


FYI, here's as far as I've gotten with my notify emulation.  this
works pretty well, but I think there's other problems in the shell
that prevent it from working perfectly.  for instance, if I do

	sleep 5 & sleep 5 & notify %1 %2

sometimes it tells me about both jobs and sometimes it loses one of
the jobs.  any ideas what else could be wrong?


trap _notify CHLD
NOTIFY_ALL=false
unset NOTIFY_LIST

_notify()
{
	typeset i j

	if $NOTIFY_ALL
	then
		jobs -n
	else
		for i in ${NOTIFY_LIST[*]}
		do
			j=`jobs -n %$i`
			if [ "$j" ]
			then
				echo "$j"
				unset NOTIFY_LIST[$i]
			fi
		done
	fi
}

notify()
{
	typeset i j

	if (($# == 0))
	then
		NOTIFY_ALL=true
	else
		for i in "$@"
		do
			# turn any valid job specification into a job number
			j=`jobs "$i"`
			case "$j" in
			\[*)
				j=${j%% *}
				j=${j%\]}
				j=${j#\[}
				NOTIFY_LIST[$j]=$j
				;;
			esac
		done
	fi
}

unnotify()
{
	if (($# == 0))
	then
		NOTIFY_ALL=false
	else
		# XXX - not done yet
		:
	fi
}