a question about expect and tcl

Question

I have a question about expect/tcl, I expect the following

expect "class room: classroom 1"
send "classroom"

send "classroom" will return "class room: classroom 1"

but this does not match, because the expected matching become

class room: classroom 1:

how to handle the ":" in expect?

Answer 1

First piece of advice for developing an expect program: before you spawn use this command

exp_internal 1

That will show you what expect sees, and you can see how it does and does not match your expected patterns.

Next, you can specify regular expressions for your patterns with expect -re {^pattern$}. The default pattern mode is glob-style matching, which is documented in Tcl's string match command. Tcl regular expressions are documented here.

Do you want to code this:

send "classroom\r"
expect -re {class room: classroom 1:?}

Answer 2

expect will match any substring

send "hello"
expect "he"

That will match. Where is the second ":" coming from in yours?