uptime w whoami id hostname apropos whatis

commandline session

$uptime
 20:57:47 up  1:41,  3 users,  load average: 0.64, 0.71, 0.70
$
$w
 20:57:49 up  1:41,  3 users,  load average: 0.64, 0.71, 0.70
USER     TTY      FROM             LOGIN@   IDLE   JCPU   PCPU WHAT
jeffrin  tty7     :0               19:16    1:41m  3:50   0.04s gdm-session-worker [pam/gdm3-autologin]
jeffrin  pts/0    :0               20:52    1:25   0.08s  0.08s bash
jeffrin  pts/1    :0               20:57    5.00s  0.05s  0.00s w
$
$whoami
jeffrin
$
$id
uid=1000(jeffrin) gid=1000(jeffrin) groups=1000(jeffrin),24(cdrom),25(floppy),29(audio),30(dip),44(video),46(plugdev),104(scanner),107(bluetooth),109(netdev)
$
$hostname
debian
$
$
$apropos apt-get
apt-get (8)          - APT package handling utility - - command-line interface
$
$whatis apt-get
apt-get (8)          - APT package handling utility - - command-line interface
$