df - Report file system disk space usage
free - Display amount of free and used memory in the system
ps - Report a snapshot of the current processes
top - Report a snapshot of the current processes
namedstatus - Show Internet domain name server service status
nginxstatus - Show HTTP and reverse proxy server, mail proxy server service status
phpfpmstatus - Show PHP FastCGI Process Manager service status
sshdstatus - Show OpenSSH SSH service status
date - Print or set the system date and time
uptime - Tell how long the system has been running
id - Print real and effective user and group IDs
ls - List directory contents
pwd - Print name of current/working directory
last - Show a listing of last logged in users
w - Show who is logged on and what they are doing
phpversion - Show PHP version number
sysinfo - Print system operation information
uname - Print system information
nc - Arbitrary TCP and UDP connections and listens
ping - Send ICMP ECHO_REQUEST to network hosts
telnet - User interface to the TELNET protocol
traceroute - Print the route packets trace to network host
curl - Transfer data from or to a server
dig - DNS lookup utility
whois - Client for the whois directory service