Shell Programming and Scripting

This is my simple expect scritpt:

#!/usr/bin/expect -f
match_max 100000
set timeout -1
spawn telnet $IP
expect "#"
send -- "shell\r"
expect "*Ready*"
send -- "init\r"
expect "*Ready*"
send -- "readsensor \r"
expect -- "*" <<< Output of this is a 2 digit number
set val $expect_out(buffer)
puts $val <<< This is empty
the 'shell' and 'init' works fine. when I get to readsensor, the output is a 2 digit number.. Even when I expect for * my expect_out(buffer) is empty..
Is there a better regex that I shd be using?
Please help me to figure this out. am I missing something... ? Please help..

Please post the expected dialog. It would help us understand what you are trying to match. It would help also to use "exp_internal 1" to see how the matching goes.

Thanks for looking into the script:

Let me tell you a little bit about what I am intending:

Based on the output of readsensor, if its > 10 do A, if it is < 10 do B.

I found one issue. I had set timeout as -1. Removed that, thought I was timing out before getting a response:

This is my script and output with exp_internal set to 1

Script and Logs:



cat checktemp.exp
#!/usr/bin/expect -f
set ipaddr [lrange $argv 0 0]
puts $ipaddr
match_max 100000
exp_internal 1
spawn telnet 192.168.137.1
expect "#"
send -- "shell\r"
expect "*Ready*"
send -- "init\r"
expect "*Ready*"
send -- "readsensor \r"
expect -- "*"
set val $expect_out(0,string)
expect "Ready*"
sleep 10s

puts "output is \n"
puts $val
send -- "quit\r"
expect "#"
send -- "exit\r"
expect eof



[root@localhost fix]# ./checktemp.exp

spawn telnet 192.168.137.1
parent: waiting for sync byte
parent: telling child to go ahead
parent: now unsynchronized from child
spawn: returns {10426}

expect: does "" (spawn_id exp6) match glob pattern "#"? no
Trying 192.168.137.1...

expect: does "Trying 192.168.137.1...\r\r\n" (spawn_id exp6) match glob pattern "#"? no
Connected to 192.168.137.1 (192.168.137.1).
Escape character is '^]'.

expect: does "Trying 192.168.137.1...\r\r\nConnected to 192.168.137.1 (192.168.137.1).\r\r\nEscape character is '^]'.\r\r\n" (spawn_id exp6) match glob pattern "#"? no


expect: does "Trying 192.168.137.1...\r\r\nConnected to 192.168.137.1 (192.168.137.1).\r\r\nEscape character is '^]'.\r\r\n\r\r\n" (spawn_id exp6) match glob pattern "#"? no



#
expect: does "Trying 192.168.137.1...\r\r\nConnected to 192.168.137.1 (192.168.137.1).\r\r\nEscape character is '^]'.\r\r\n\r\r\n\r\n\r\nBusyBox v1.2.1 (2009.03.26-17:02+0000) Built-in shell (msh)\r\nEnter 'help' for a list of built-in commands.\r\n\r\n# " (spawn_id exp6) match glob pattern "#"? yes
expect: set expect_out(0,string) "#"
expect: set expect_out(spawn_id) "exp6"
expect: set expect_out(buffer) "Trying 192.168.137.1...\r\r\nConnected to 192.168.137.1 (192.168.137.1).\r\r\nEscape character is '^]'.\r\r\n\r\r\n\r\n\r\nBusyBox v1.2.1 (2009.03.26-17:02+0000) Built-in shell (msh)\r\nEnter 'help' for a list of built-in commands.\r\n\r\n#"
send: sending "shell\r" to { exp6 }

expect: does " " (spawn_id exp6) match glob pattern "*Ready*"? no
r
expect: does " r" (spawn_id exp6) match glob pattern "*Ready*"? no
dshell

expect: does " shell\r\n" (spawn_id exp6) match glob pattern "*Ready*"? no
[Ready]>
expect: does " shell\r\n[Ready]> " (spawn_id exp6) match glob pattern "*Ready*"? yes
expect: set expect_out(0,string) " shell\r\n[Ready]> "
expect: set expect_out(spawn_id) "exp6"
expect: set expect_out(buffer) " shell\r\n[Ready]> "
send: sending "init\r" to { exp6 }

expect: does "" (spawn_id exp6) match glob pattern "*Ready*"? no
init

expect: does "init\r\n" (spawn_id exp6) match glob pattern "*Ready*"? no
init return status is 0

expect: does "init\r\ninit return status is 0\r\n" (spawn_id exp6) match glob pattern "*Ready*"? no
[Ready]>
expect: does "init\r\ninit return status is 0\r\n[Ready]> " (spawn_id exp6) match glob pattern "*Ready*"? yes
expect: set expect_out(0,string) "init\r\ninit return status is 0\r\n[Ready]> "
expect: set expect_out(spawn_id) "exp6"
expect: set expect_out(buffer) "init\r\ninit return status is 0\r\n[Ready]> "
send: sending "readsensor \r" to { exp6 }

expect: does "" (spawn_id exp6) match glob pattern "*"? yes
expect: set expect_out(0,string) ""
expect: set expect_out(spawn_id) "exp6"
expect: set expect_out(buffer) ""

expect: does "" (spawn_id exp6) match glob pattern "Ready*"? no
readsensor

expect: does "readsensor \r\n" (spawn_id exp6) match glob pattern "Ready*"? no
48

expect: does "readsensor \r\n48\r\n" (spawn_id exp6) match glob pattern "Ready*"? no
[Ready]>
expect: does "readsensor \r\n48\r\n[Ready]> " (spawn_id exp6) match glob pattern "Ready*"? yes
expect: set expect_out(0,string) "Ready]> "
expect: set expect_out(spawn_id) "exp6"
expect: set expect_out(buffer) "readsensor \r\n48\r\n[Ready]> "
output is


send: sending "quit\r" to { exp6 }

expect: does "" (spawn_id exp6) match glob pattern "#"? no
quit

expect: does "quit\r\n" (spawn_id exp6) match glob pattern "#"? no
#
expect: does "quit\r\n# " (spawn_id exp6) match glob pattern "#"? yes
expect: set expect_out(0,string) "#"
expect: set expect_out(spawn_id) "exp6"
expect: set expect_out(buffer) "quit\r\n#"
send: sending "exit\r" to { exp6 }
exit
Connection closed by foreign host.
expect: read eof
expect: set expect_out(spawn_id) "exp6"
expect: set expect_out(buffer) " exit\r\nConnection closed by foreign host.\r\r\n"
write() failed to write anything - will sleep(1) and retry...

You have two expect statements in a row so the second expect is not triggered. After the "ecpect -- "*"" line you need to send_user or just send "\r" so the next "expect "*Ready*" is triggered.

Code:

end -- "readsensor \r"
expect -- "*"
set val $expect_out(0,string)
expect "Ready*"

Thanks for the response.. tried it and this is what I see
this is my script..

send -- "readsensor \r"
expect -- "*"
set val $expect_out(0,string)
send -- "\r"
expect "Ready*"
sleep 10s

puts "output is \n"
puts $val
send -- "quit\r"
expect "#"
send -- "exit\r"
expect eof



expect: does "readsensor \r\n\r\n[Ready]> command error ERR_UNKNOWN_CMD - command: \r\n\r\n" (spawn_id exp6) match glob pattern "Ready*"? yes
expect: set expect_out(0,string) "Ready]> command error ERR_UNKNOWN_CMD - command: \r\n\r\n"
expect: set expect_out(spawn_id) "exp6"
expect: set expect_out(buffer) "readsensor \r\n\r\n[Ready]> command error ERR_UNKNOWN_CMD - command: \r\n\r\n"
output is


send: sending "quit\r" to { exp6 }

expect: does "" (spawn_id exp6) match glob pattern "#"? no
49
[Ready]> [Ready]>
expect: does "49\r\n[Ready]> [Ready]> " (spawn_id exp6) match glob pattern "#"? no
quit

expect: does "49\r\n[Ready]> [Ready]> quit\r\n" (spawn_id exp6) match glob pattern "#"? no
#
expect: does "49\r\n[Ready]> [Ready]> quit\r\n# " (spawn_id exp6) match glob pattern "#"? yes
expect: set expect_out(0,string) "#"
expect: set expect_out(spawn_id) "exp6"
expect: set expect_out(buffer) "49\r\n[Ready]> [Ready]> quit\r\n#"
send: sending "exit\r" to { exp6 }
exit
Connection closed by foreign host.
expect: read eof
expect: set expect_out(spawn_id) "exp6"
expect: set expect_out(buffer) " exit\r\nConnection closed by foreign host.\r\r\n"
write() failed to write anything - will sleep(1) and retry...

Based on the error it appears that hitting the {return} key "\r" is not a valid command at the [Ready] prompt. If you do not want to send a command to the utility at his point because you need to wait on some response to come back the change the (send -- "\r") to send_user -- "Waiting on response from readsensor command...\r" NOTE the '\r' may be a '\n' it has been a while sense I wrote an Expect script.