Here Documents: Multi-Line Input Inline

A here document feeds several lines of input to a command without a separate file — everything between <<MARKER and a line containing only MARKER becomes the command's stdin.

Two tasks that turn on the ONE detail that trips everyone up — whether the marker is quoted. Put both in one script, /root/case/heredocs.sh, so the result can be re-run by anyone:

1. Write /root/out/motd.txt with cat and an UNQUOTED here-doc so the shell expands a variable inside it. The file must contain a line reading exactly:

Welcome, <the user running the script>

(produced by embedding $USER — as root that is "Welcome, root").

2. Write /root/out/template.sh with a QUOTED here-doc (<<'EOF') so the text is verbatim. It must contain the literal, UN-expanded line:

echo "Deploying as $USER"

Here the $USER must survive as literal text — which only a quoted marker guarantees.

Same tool, opposite behavior, decided entirely by the quotes on the marker. Grading runs your script as a different user and reads the files it writes, so the motd must really come from $USER.