expect script stop after sending \003 - shell

Question

Need some assistance on an expect script where it would not continue. The function of the script is to connect on remote hosts, change user then ran a command. But i place a else statement that when the change user prompts to update password it will just skip that and continue on the next host. However the script stops on the point where i send \003.The expect script is indicated below;
#!/usr/bin/expect -f
set i [open "eposhosts"]
set hosts [split [read -nonewline $i] "\n"]
foreach host $hosts {
spawn /usr/bin/ssh -q appadm#$host
expect "appadm#$host:~>"
send "su epos\r"
expect "Password:"
send "password\r"
expect {
"epos#$host:/home/appadm>" {send "grep playlist /appl/epos/bin/cron.epos\r"; exp_continue}
"(current) UNIX password:" {send "\003"; exp_continue}
}
expect {
"epos#$host:/home/appadm>" {send "exit\r"; exp_continue}
"[appadm#$host ~]" {send "exit\r"}
}
expect "appadm#$host:~>"
send "exit\r"
expect eof
}

Answer 1

From the error message, it looks like the problem is because of un-escaped open square bracket [. If you want to match literal open square bracket, then it should be,
"\\\[appadm#$host ~]"
The reason is, [ is special to both Tcl and Expect. Unless escaped, it will treated as a command call.
Change your code as,
expect {
"epos#$host:/home/appadm>" {send "exit\r"; exp_continue}
"\\\[appadm#$host ~]" {send "exit\r"}
}
Note : We don't need to escape the close square bracket.

Answer 2

The value \003 is controlC (^C), which is likely to be an interrupt character on receiving terminal. If expect sends that as expected, it can very well stop a program.
Responding to comment by #Dren:
If you send newlines, the change-password prompt will probably reject that (no empty passwords...) and will not stop your script.
For instance
{send "\n\n\n"; exp_continue}
rather than
{send "\003"; exp_continue}