This is a small oneshot timer utility implemented in C.
Usage: rtimer [-- command [args...]]
Examples: rtimer 5 rtimer 2.5 -- echo "Hello after 2.5s"
Behavior:
- Waits the specified number of seconds (supports fractional values).
- After the wait, if a command is given it executes it and exits with the command's exit code.
- If no command is given, exits 0 after sleeping.