Find the Command (apropos to the Rescue)

Three jobs — but this time you're not told WHICH command. Describe the job to apropos (or man -k), find the tool, run it, and save the output under /root/answers/ (already created):

1. uptime.txt — 'tell how long the system has been running.' (apropos that phrase.)

2. disk.txt — 'report file system disk space usage'

3. kernel.txt — print JUST the kernel release string. (apropos kernel — then check the command's man page for the release flag.)

Each quoted string above is the command's real one-line man description, copied exactly — apropos matches your words against those descriptions, so a word the description doesn't contain (or a trailing '.' it doesn't have) finds nothing.

Describing the job and letting the system name the tool is the reverse lookup every self-sufficient Linux user leans on.