与TCL /期望和思科的意外行为

Question

I'm trying to log into a Cisco switch and run a list of commands.
Using the following code, I'm able to log into the device, enable, and configure terminal:

    # Connect to single host, enable, and configure
    proc connect {host payload username password enablepassword} {

send_user "Connecting to: $host $payload $username $password $enablepassword\n"

spawn ssh -o "StrictHostKeyChecking no" -l $username $host

# # Pardon the rudeness; some switches are upper case, some are lower case
expect "assword:"
send "$password\r"

# Switch to enable mode
expect ">" 
send "en\r"

expect "assword:"
send "$enablepassword\r"
expect "*#"
send -- "conf t\r"

expect "config*#"
}

However, using the following code, I get the output below. ($payload contains a file which has one IOS command per line)

proc drop_payload {payload} {
set f [open "$payload"]
set payload [split [read $f] "\n"]
close $f

foreach pld $payload {

    send -- "$pld\r"
    expect "config*#"

    sleep 2
}
}

My expectation is that this loop will iterate over each line in the file, however, the Expect debug (from exp_internal 1) is as follows:

    HOST-0001#
expect: does " \r\HOST-0001#" (spawn_id exp7) match glob pattern "*#"? yes
expect: set expect_out(0,string) " \r\nHOST-0001#"
expect: set expect_out(spawn_id) "exp7"
expect: set expect_out(buffer) " \r\nHOST-0001#"
send: sending "conf t\r" to { exp7 }

expect: does "" (spawn_id exp7) match glob pattern "config*#"? no
c
expect: does "c" (spawn_id exp7) match glob pattern "config*#"? no
o
expect: does "co" (spawn_id exp7) match glob pattern "config*#"? no
n
expect: does "con" (spawn_id exp7) match glob pattern "config*#"? no
f
expect: does "conf" (spawn_id exp7) match glob pattern "config*#"? no

expect: does "conf " (spawn_id exp7) match glob pattern "config*#"? no
t
expect: does "conf t" (spawn_id exp7) match glob pattern "config*#"? no


expect: does "conf t\r\n" (spawn_id exp7) match glob pattern "config*#"? no
Enter configuration commands, one per line.  End with CNTL/Z.
HOST-0001(config)#
expect: does "conf t\r\nEnter configuration commands, one per line.  End with CNTL/Z.\r\nHOST-0001(config)#"     (spawn_id exp7) match glob pattern "config*#"? yes
expect: set expect_out(0,string) "configuration commands, one per line.  End with CNTL/Z.\r\nHOST-0001(config)#"
expect: set expect_out(spawn_id) "exp7"
expect: set expect_out(buffer) "conf t\r\nEnter configuration commands, one per line.  End with CNTL/Z.\r\nHOST-0001(config)#"
}end: sending "no logging 172.x.x.20\r" to { exp0 no logging 172.x.x.20

expect: does "" (spawn_id exp0) match glob pattern "config*#"? no
expect: timed out
}end: sending "no logging 172.x.x.210\r" to { exp0 no logging 172.x.x.210

expect: does "" (spawn_id exp0) match glob pattern "config*#"? no
expect: timed out
}end: sending "no logging 172.x.x.9\r" to { exp0 no logging 172.x.x.9

expect: does "" (spawn_id exp0) match glob pattern "config*#"? no
expect: timed out
}end: sending "no logging 172.x.x.210\r" to { exp0 no logging 172.x.x.210

expect: does "" (spawn_id exp0) match glob pattern "config*#"? no
expect: timed out
}end: sending "no logging 172.x.x.20\r" to { exp0 no logging 172.x.x.20

expect: does "" (spawn_id exp0) match glob pattern "config*#"? no
expect: timed out
}end: sending "logging 172.x.x.50\r" to { exp0 logging 172.x.x.50

expect: does "" (spawn_id exp0) match glob pattern "config*#"? no
expect: timed out

I'm confused as to why it's trying to expect "conf t" which is being sent to the host; not received.
I'm also confused as to why any of the commands end after conf t is applied don't hit the switch, and time out instead.

Answer 1

You can try sending the configurations with the spwan_id

spawn ssh -o "StrictHostKeyChecking no" -l $username $host
#After process creation the process id will be saved in 
#standard expect variable'spawn_id'
#Copying it to variable 'id'
set id $spawn_id

Now the variable 'id' is holding the reference to the ssh process. We can very well use the send and expect with the spawn id.

#Now we are setting the spawn id to our ssh process to make sure 
#we are sending the commands to right process
#You can pass this variable 'id' as arg in 'drop_payload'

set spawn_id $id


foreach pld $payload {

    send -- "$pld\r"
    expect "config*#"

    sleep 2
}

Or the other way around is as follows,

foreach pld $payload {
    #This way is useful, when u want to send and expect to multiple process 
    #simultaneously.
    send -i $id "$pld\r"
    expect -i $id "config*#"

    sleep 2
}

Answer 2

I found that each function/procedure was outputting to a new spawn ID.

One method is to follow Dinesh's advice and explicitly define the spawn id.

My workaround was to simply stuff everything into a single output procedure.