service command – list running services
The syntax is as follows for CentOS/RHEL 6.x and older (pre systemd):
service --status-all
service --status-all | more
service --status-all | grep ntpd
service --status-all | less
Print the status of any service
To print the status of apache (httpd) service:
service httpd status
List all known services (configured via SysV)
chkconfig --list
List service and their open ports
netstat -tulpn