Here is a line from a bash script I am trying to understand:echo spawn myscript.sh arg1 arg2; expect \Please enter your value: \; send \myval\r\; expect eof | expectI think I understand the first expect and the send.  Q1:  Does expect work only with spawn? Q2:  What is the purpose of the last expect after the pipe? Q3:  In general, can you guess what the original author of this line was attempting to accomplish?
Help me understand this echo/spawn/send/expect construct
shell;pipe;expect
Q1: The purpose of expect is to automate interactive programs. To launch the program and interact with it, you use the spawn command.Q2: the last expect after the pipe is the expect binary. If not given a file argument, it reads its stdin to get the script to execute.Q3: The author wanted a mechanism to automatically pass a value when the script  prompts for one. That's it.I strongly suspect (depending on what myscript.sh does) that you don't need expect at all:echo myval | myscript.sh arg1 arg2