linux —— 基础——whatis & info & man & which & whereis
#man -k root@bae226a5b14a:/etc/dpkg/dpkg.cfg.d# man -k man add_key (2) - add a key to the kernel's key management facility at (1posix) - execute commands at a later time batch (1posix) - schedule commands to be executed in a batch queue bpf (2) - perform a command on an extended BPF map or program bsd_signal (3) - signal handling with BSD semantics command (1posix) - execute a simple command copysign (3posix) - number manipulation function cproj (3) - project into Riemann Sphere cprojf (3) - project into Riemann Sphere cprojl (3) - project into Riemann Sphere CPU_ALLOC (3) - macros for