Which command line can be used to search help files that mention the word "copy"?

Luis F.Jun 26, 2026

A is the one you want here. "man -k copy" does a keyword search across all man page descriptions, so it pulls up any command that mentions "copy" in its short description line. That is exactly what you need when you don't know the specific command name but you know what it does. The other options either require you to already know the command name (man copy, whatis copy, copy --help) or are just not valid Linux commands at all (copy help).

Carlos M.Jun 23, 2026

A is right. "man -k copy" does a keyword search across all man page descriptions, which is exactly what you want when you don't know the specific command name but remember what it does. The tricky one here is B, "whatis copy," because it also queries the man page database, but whatis only returns entries where "copy" is the exact command name, not a keyword mentioned somewhere in the description. C just opens the man page for a command literally named "copy," which probably doesn't exist, and D and E don't even make sense as real syntax in any standard Unix environment.

Hiroshi T.Jun 26, 2026

man -k is the keyword search; whatis only matches exact names, so A.