When you can’t pipe an input file to automate a process, especially when you need to enter a password such as ftp-ing to some server e.g.:

ftp user@ftp.myhost.com < myFTPCommands.txt

The above fails when ftp asks for a password. This is where expect comes to the rescue! e.g.:

#myExpectFile.exp

#Disable’s expect’s default 10 seconds timeout
set timeout -1

spawn ftp user@ftp.myhost.com
expect [...]