On Mon, Aug 20, 2018 at 10:29:46AM +1000, luv-main wrote:
> Hi All,
>
> I'm having some trouble making expect work.
>
> I need it to talk to some vintage equipment over usb serial, and I think
> I'm getting hung up on opening the port.
>
> When the script runs, it just connects to the device and sits there. I can
> drive it interactively, but it doesn't attempt to automate anything.
>
> Any ideas? Thanks.
>
> My expect script looks like this:
>
> #!/usr/bin/expect -f
>
> # device
> set modem /dev/ttyUSB0
>
> # keep it open
> exec sh -c "sleep 3 < $modem" &
>
> # serial port parameters
> exec stty -F $modem 2400 raw -clocal -echo -istrip -hup
>
> # connect
> send_user "connecting to $modem, exit with ~,\n"
> spawn -open [open $modem w+]
> interact {
> ~, exit
> ~~ {send "\034"}
> }
>
> set force_conservative 1 ;# set to 1 to force conservative mode even if
> ;# script wasn't run conservatively originally
> if {$force_conservative} {
> set send_slow {1 .1}
> proc send {ignore arg} {
> sleep .1
> exp_send -s -- $arg
> }
> }
>
> set timeout -1
> match_max 100000
> send -- "\r"
> send -- "\r"
> expect ">"
> send -- "p 7d91\r"
> expect ">"
> send -- "p b2ff\r"
> expect ">"
> send -- "h\r"
> expect ">"
> send -- "td\r"
> expect "td\r
> 18 215 12 24 33\r
> >"
> send -- "gd 215\r"
> expect eof
What a mess. Could you tidy it a little, or a lot?
You don't need slow send with these short character sequences.
You can do the shell lines before you start expect (as I'll demonstrate).
I used to do a lot of (USB or not) serial stuff and never found I needed that
sleep 3 thing. Once you set serial line params, they stay that way until a
process changes them. Tcl open does not change them unless you tell it to.
Anyway, sleep 3 <$modem is likely sucking up response characters.
*exp_internal 1* is your friend when debugging expect scripts,
Cheers ... Duncan.
===================
#!/bin/sh
# expect sees the next line as a comment continuation \
# You can put shell lines here as long as you end them semicolon backslash \
modem=${modem:-/dev/ttyUSB0};\
export modem;\
stty -F $modem 2400 raw -clocal -echo -istrip -hup;\
\
# Really start expect \
exec expect -- "$0" "$@"
puts "connecting to $env(modem), exit with ~,"
spawn -open [open $env(modem) r+] ;# rw, no truncate
exp_internal 1 ;# Comment-out once working
interact {
{~,} {exit}
{~~} {send "\034"}
}
# and so on
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