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How to use Bash script variables in expect conditional statements?
Since you are calling this Expect script from another process, you can make use of environment variables. For example, if your parent process has exported action to the environment, then you can access its value within your expect script with: In Bash, you can mark the variable for export with the export builtin.
What to do with output from Expect script?
“send_user” output that gets sent to stdout. This is used for sending message to the screen as the script runs. It is great for user feedback, banners, and for generating error messages. Thanks for contributing an answer to Unix & Linux Stack Exchange!
How to pass argument in expect through the command line?
I am passing argument in Expect through the command line in a shell script. But it’s not working. How can I fix it? However, your method should work as well.
Which is the best way to use expect?
Another alternative is not to use expect at all, but use perl’s Expect.pm or python’s pexpect instead. These work in pretty much the same way as expect but make it easier to extract data from the expect session. I still think that there are far better ways to get the IP address of a VM than using expect on virsh console.
How to copy a variable into a file?
Also, if your variable contains a secret and you want to copy that secret into a file, you might want to not have expansion in the command line as tracing/command echo of the shell commands might reveal the secret.
How to print the contents of a variable?
Another option is printf, but printf “$var” > “$destdir” will expand any escaped characters in the variable, so if the variable contains backslashes the file contents won’t match.
How to disable output from spawned processes in expect?
To disable logging to standard output from spawned processes, Expect provides the log_user command. You can prevent your spawned processes from writing to stdout with log_user 0.