你已经在等待循环结束时的 eof，你只需要使用 wait 和 catch 结果:

You're already waiting for the eof at the end of your loop, you just need to use wait and catch the result:

spawn true
expect eof
catch wait result
exit [lindex $result 3]

以 0 退出.

spawn false
expect eof
catch wait result
exit [lindex $result 3]

以 1 退出.