Find the one-line description of a command fast and reliably. 29.05.2026 | reading time: 2 min Need a very short description of a program? The `whatis` command returns the one-line summary from a man page so he can decide where to look next; short and direct, perfect for quick checks. Lookup in seconds Try this live: ```bash $ whatis ls ls (1) - list directory contents $ man -f ls ls (1) - list directory contents ``` This shows that `whatis` and `man -f` produce the same one-line NAME entry. Where the answers come from `whatis` reads the man-page NAME section from the whatis database that `mandb` or `makewhatis` builds, so entries exist only when a man page is installed; use `apropos` or `man -k` for broader keyword searches when `whatis` returns nothing. Practical tips If `whatis` says there is no entry, rebuild the database with `mandb` or install the package that provides the man page; remember `whatis` gives concise pointers, not full documentation, so follow up with `man` for details. Bring it together A tiny tool, but high leverage: use `whatis` to confirm names and purposes before diving into `man` or online docs, then practice frequently to build command intuition; for formal preparation consider CompTIA Linux+ or LPIC-1 study and intensive exam training at bitsandbytes.academy. Join Bits & Bytes Academy First class LINUX exam preparation. utilities troubleshooting scripting
