How to use expect to spawn with arguments from command line?

Question

Suppose that I call my.exp by

my.exp cmd a b c d ...

I want to pass all the arguments of my.exp to spawn. But I don't find a way to do so. Is there a way to do it with expect? Thanks.

#!/usr/bin/env expect

spawn $argv
...

Answer 1

You'd want to use tcl's argument expansion syntax to do this:

spawn {*}$argv

Example

my.exp:

#!/usr/bin/env expect
log_user 0
puts "Spawning '$argv'"
spawn {*}$argv
expect *foo* { puts "Got: '[string trim $expect_out(buffer)]'" }

Usage:

$ ./my.exp echo foo bar
Spawning 'echo foo bar'
Got: 'foo bar'