rm
FilesPackage: coreutilsHandle with care
Deletes files, with no bin and no confirmation. What rm -rf removes is gone; the only protection is what you typed before Enter, and an empty variable turns /var/www/$app into /var/www/ there.
A mistake with this command can destroy data or lock you out
rm -rfon a path built from a variable: if the variable is empty, the target is the parent directory. Write"${app:?}"so the shell refuses, andlsthe target first.
What its options do in the lessons
From the same glossary the lessons render under their commands, so the two cannot disagree.
rm -r- Removes a directory and everything in it.
rm -f- Asks nothing and ignores missing files. Combined with
-r, nothing stops you: this is the pairing never to type from memory. rm -i- Asks for confirmation on every file. Safe, and quickly unbearable: over a hundred files you answer “yes” a hundred times without reading.
rm -I- Asks once, and only from three files upwards or with
-r. This is the useful compromise: the question comes when the command is large, which is when it deserves re-reading.