Linux Expect Script terminates too early

vmtouch seems like a good tool for the job.

Highlights:

• query how much of a directory is cached
• query how much of a file is cached (also which pages, graphical representation)
• load file into cache
• remove file from cache
• lock files in cache
• run as daemon

vmtouch manual

EDIT: Usage as asked in the question is listed in example 5 on vmtouch Hompage

Example 5

Daemonise and lock all files in a directory into physical memory:

vmtouch -dl /var/www/htdocs/critical/

EDIT2: As noted in the comments, there is now a git repository available.

First thing, your heredoc acts like a double quoted string, so the $expect_out variable is being substituted by the shell before expect starts. You need to ensure your heredoc is not being touched by the shell. Therefore, any shell variables need to be fetched in a different way. Here, I'm assuming IP is a shell variable, and I'm passing it through the environment.

export IP
/usr/bin/expect << 'ENDOFEXPECT'
  set prompt ":~#"
  spawn ssh root@$env(IP)  
  expect "password:"
  send "xxxx\r"
  expect $prompt
  send "grep hostname /etc/rc.d/rc.local \n"
  expect $prompt
  set line $expect_out(buffer)
  ...more script...
ENDOFEXPECT