https://www.pantz.org/software/expect/expect_examples_and_tips.html
https://inguza.com/document/expect-and-tcl-mini-reference-manual
https://petervibert.com/wp/expect-smtp-script/
https://stackoverflow.com/questions/12320592/telnet-smtp-with-expect-or-shell-script
https://wiki.tcl-lang.org/page/Checking+your+IMAP+mail+with+Expect
https://stackoverflow.com/questions/19952070/expect-output-write-to-a-file
https://www.tcl.tk/man/tcl8.4/TclCmd/puts.htm
https://www.unix.com/shell-programming-and-scripting/148687-tcl-expect-using-puts-add-data-file.html
https://stackoverflow.com/questions/13052232/expect-puts-write-to-file