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From: horia314 on 28 Jul 2010 04:34
Hello,

I've run into a strange issue while using tcl with the tclreadline and
expect libraries. I don't know if it's a bug or if I'm doing something
wrong, but any help would be appreciated.

This is the smallest test example I can think of for which the problem
is reproducible:

package require tclreadline
package require Expect

after 5000 {spawn ls} # any delay and any shell command words.

tclreadline::readline initialize history
while 1 {
tclreadline::readline read {> }
}

The readline built "shell" works fine until the after event triggers,
at which point the program stops responding and I have to kill it with
Ctrl+C (I think tclreadline dies somehow). Using other commands (even
exec and open) in the after script or using other commands that wait
(vwait) in the while script works.

I don't know why this happenes, but I suspect it has something to do
with the way expect forks a process. From what I've dug
"tclreadline::readline read" enters into a loop, waiting for
libreadline to signal that a valid line has been read, and does
Tcl_DoOneEvent in the meanwhile. Maybe after combined with spawn
messes with it's processing.

I have a workaround for this issue (I launch the tclreadline part of
the application in a separate script, with exec) but any help or
insights on this issue would be helpful.

Thank You,
Horia

PS. I use the latest tcl, tclreadline and expect versions (8.5.8,2.1.0
and 5.44.1.15 respectivly).
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