.I made a simple TCL/expect script to capture via regexp some mac-addresses from a command that I usually run on our Wireless Access Controller.
The thing that I dont understand is that I always miss the first 14-15 lines of command's output from the buffer.
#!/usr/bin/expect
log_file -a -noappend wlac.log
#global spawn_id
set timeout 5
#set exp_internal 1
#exp_internal -f debug_wlac.log 1
match_max 700000
set userf userfile
#username
set pwdf pwdfile
#password
set commands "sta-all"
#commands = display station all
set hostsls "wlac"
#hostsls= hostnames list
set f [open $userf]
set user [read $f]
close $f
set f [open $pwdf]
set password [read $f]
close $f
set f [open "$hostsls"]
set hosts [split [read $f] "\n"]
close $f
set f [open "$commands"]
set commands [split [read $f] "\n"]
close $f
foreach host $hosts {
if {[string trim $host] eq ""} then continue
send_user "\n"
send_user ">>>>> Working on $host @ [exec date] <<<<<\n"
send_user "\n"
spawn ssh -o GlobalKnownHostsFile=/dev/null -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -o AddKeysToAgent=yes "$user@$host"
expect {
"assword"
{
send "$password\n"
}
">"
{
send \n
}
}
foreach cmd $commands {
expect {
">"
{
append maclist $expect_out(buffer)
send "$cmd\n"
}
"More"
{
append maclist $expect_out(buffer)
send "\n"
exp_continue
}
}
}
}
set pattern_mac {[0-9A-Fa-f]{4}[-][0-9A-Fa-f]{4}[-][0-9A-Fa-f]{4}}
set match_maclist [regexp -all -inline $pattern_mac $maclist]
puts "\n"
puts "***Beginning of Output***"
puts "\n"
puts $maclist
puts "\n"
puts "***print array elements***"
puts "\n"
foreach i $match_maclist { puts $i }
puts [llength $match_maclist]
expect ">"
send "quit\n"
close
wait
send_user "\n"
I see from the logs, that I always miss this part, that is more or less the first 14 lines of output after the command "display station all" The rest of the output buffer has everything that I expect to be there. I tried enabling the debug log, but I didn't notice anything strange.
<wlac-hostname>display station all
Rf/WLAN: Radio ID/WLAN ID
Rx/Tx: link receive rate/link transmit rate(Mbps)
---------------------------------------------------------------------------------------------------------------------------------------
STA MAC AP ID AP name Rf/WLAN Band Type Rx/Tx RSSI VLAN IP address SSID
---------------------------------------------------------------------------------------------------------------------------------------
aaaa-bbbb-cc11 1111 AP-HOSTNAME 1/1 5G 11n 130/117 -55 1111 1.1.1.1 ssid-name
aaaa-bbbb-cc11 1111 AP-HOSTNAME 1/1 5G 11n 130/117 -55 1111 1.1.1.1 ssid-name
aaaa-bbbb-cc11 1111 AP-HOSTNAME 1/1 5G 11n 130/117 -55 1111 1.1.1.1 ssid-name
aaaa-bbbb-cc11 1111 AP-HOSTNAME 1/1 5G 11n 130/117 -55 1111 1.1.1.1 ssid-name
aaaa-bbbb-cc11 1111 AP-HOSTNAME 1/1 5G 11n 130/117 -55 1111 1.1.1.1 ssid-name
aaaa-bbbb-cc11 1111 AP-HOSTNAME 1/1 5G 11n 130/117 -55 1111 1.1.1.1 ssid-name
aaaa-bbbb-cc11 1111 AP-HOSTNAME 1/1 5G 11n 130/117 -55 1111 1.1.1.1 ssid-name
aaaa-bbbb-cc11 1111 AP-HOSTNAME 1/1 5G 11n 130/117 -55 1111 1.1.1.1 ssid-name
aaaa-bbbb-cc11 1111 AP-HOSTNAME 1/1 5G 11n 130/117 -55 1111 1.1.1.1 ssid-name
aaaa-bbbb-cc11 1111 AP-HOSTNAME 1/1 5G 11n 130/117 -55 1111 1.1.1.1 ssid-name
aaaa-bbbb-cc11 1111 AP-HOSTNAME 1/1 5G 11n 130/117 -55 1111 1.1.1.1 ssid-name
(ip, hostname, and other stuff are just examples)
After this point, everything is ok. I did a check, and this isn't happening where there is a "---- More ----" but way before.
I suspect the expect input buffer is too small, which is why you have match_max 700000. Unfortunately, this has no effect as it applies to the currently spawned process, of which there is none.
You need to set at the start the default size, for future spawn commands by using:
match_max -d 700000