Expect not waiting for prompt - script stops without sending other commands - expect

Question

Before this is chalked up as a timeout, or max_match issue, I will say that I have tried those. I have also tried using full_buffer, but it seems the only fix is to put a sleepafter theexpect when a large output comes before it. It's almost as if the expect ">$" is seen and processed by expect before the terminal can print the output.
term len 0 is a cisco command to basically prevent the default | more of the file
Example:
set timeout -1
spawn ssh host
expect "assword:"
send "$pass\r"
expect ">$"
send "term len 0\r"
expect ">$"
set size_orig [match_max]
match_max 60000000
send "show start\r"
expect ">$"
does not work. The output of "show start" is stopped x lines into the output.
If I put handling for timeout and full_buffer, the same thing happens:
set timeout -1
spawn ssh host
expect "assword:"
send "$pass\r"
expect ">$"
send "term len 0\r"
expect ">$"
set size_orig [match_max]
match_max 60000000
set timeout -1
send "show start\r"
expect {
timeout {
send $expect_out(buffer)
}
full_buffer {
send $expect_out(buffer)
}
">$" {
append outcome $expect_out(buffer)
}
}
The only way I was able to fix this was adding a sleep after the expect ">$" (I did this in the simple script below, and also in the script which handles full_buffer and timeout) :
set timeout -1
spawn ssh host
expect "assword:"
send "$pass\r"
expect ">$"
send "term len 0\r"
expect ">$"
set size_orig [match_max]
match_max 60000000
set timeout -1
send "show start\r"
expect ">$"
sleep 10
This works, but is there a proper way to do this as opposed to making the script wait by sleeping? Not all of the devices have such large outputs, so the sleep is not needed on each host.
one additional test I made was running the script with expect -d and the following was at the end of the truncated ouput:
tty_set: raw = 3, echo = 0
Thanks,
chris

Answer 1

The following resolved the issue in my script by suppressing the output displayed to the user, and rather, appending it to my log_file :
log_file -a initial_commands
log_user 0
send "some commands with large output"
log_file
log_user 1
In this case it does not matter whether the user sees the output, as I am parsing it and outputting it to a file anyway. To further disprove it was an error in my expect "<$" code, I experienced this same behavior (by complete accident) when running system "parse.pl". That perl script simply read the large output of show start and printed it line by line. Sure enough, the output stopped short and the script stopped. If anyone would like to dive deeper into this issue, please let me know and I can gladly provide more info.